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Use near bpb on the stack in bpb_to_dpb. 

Make sure the number of FAT sectors is actually enough to hold that
many clusters. Otherwise back the number of clusters down (LG & AB)


git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/trunk@655 6ac86273-5f31-0410-b378-82cca8765d1b
This commit is contained in:
Bart Oldeman 2003-08-28 20:30:09 +00:00
parent 68805961dc
commit c444161296
1 changed files with 36 additions and 15 deletions
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51
kernel/fatfs.c
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@ -1985,24 +1985,45 @@ VOID bpb_to_dpb(bpb FAR * bpbp, REG struct dpb FAR * dpbp)
{
ULONG size;
REG UWORD shftcnt;
bpb sbpb;
for (shftcnt = 0; (bpbp->bpb_nsector >> shftcnt) > 1; shftcnt++)
fmemcpy(&sbpb, bpbp, sizeof(sbpb));
for (shftcnt = 0; (sbpb.bpb_nsector >> shftcnt) > 1; shftcnt++)
;
dpbp->dpb_shftcnt = shftcnt;
dpbp->dpb_mdb = bpbp->bpb_mdesc;
dpbp->dpb_secsize = bpbp->bpb_nbyte;
dpbp->dpb_clsmask = bpbp->bpb_nsector - 1;
dpbp->dpb_fatstrt = bpbp->bpb_nreserved;
dpbp->dpb_fats = bpbp->bpb_nfat;
dpbp->dpb_dirents = bpbp->bpb_ndirent;
size = bpbp->bpb_nsize == 0 ? bpbp->bpb_huge : (ULONG) bpbp->bpb_nsize;
dpbp->dpb_fatsize = bpbp->bpb_nfsect;
dpbp->dpb_mdb = sbpb.bpb_mdesc;
dpbp->dpb_secsize = sbpb.bpb_nbyte;
dpbp->dpb_clsmask = sbpb.bpb_nsector - 1;
dpbp->dpb_fatstrt = sbpb.bpb_nreserved;
dpbp->dpb_fats = sbpb.bpb_nfat;
dpbp->dpb_dirents = sbpb.bpb_ndirent;
size = sbpb.bpb_nsize == 0 ? sbpb.bpb_huge : (ULONG) sbpb.bpb_nsize;
dpbp->dpb_fatsize = sbpb.bpb_nfsect;
dpbp->dpb_dirstrt = dpbp->dpb_fatstrt + dpbp->dpb_fats * dpbp->dpb_fatsize;
dpbp->dpb_data = dpbp->dpb_dirstrt
+ (dpbp->dpb_dirents + dpbp->dpb_secsize/DIRENT_SIZE - 1) /
(dpbp->dpb_secsize/DIRENT_SIZE);
dpbp->dpb_size = ((size - dpbp->dpb_data) >> shftcnt) + 1;
{ /* Make sure the number of FAT sectors is actually enough to hold that */
/* many clusters. Otherwise back the number of clusters down (LG & AB) */
unsigned fatsiz;
ULONG tmp = dpbp->dpb_fatsize * (ULONG)(dpbp->dpb_secsize / 2);/* entries/2 */
if (tmp >= 0x10000)
goto ckok;
fatsiz = (unsigned) tmp;
if (dpbp->dpb_size > FAT_MAGIC) {/* FAT16 */
if (fatsiz <= FAT_MAGIC) /* FAT12 - let it pass through rather */
goto ckok; /* than lose data correcting FAT type */
} else { /* FAT12 */
if (fatsiz >= 0x4000)
goto ckok;
fatsiz = fatsiz * 4 / 3;
}
if (dpbp->dpb_size >= fatsiz) /* FAT too short */
dpbp->dpb_size = fatsiz - 1; /* - 2 reserved entries + 1 */
ckok:;
}
dpbp->dpb_flags = 0;
dpbp->dpb_cluster = UNKNCLUSTER;
/* number of free clusters */
@ -2011,8 +2032,8 @@ VOID bpb_to_dpb(bpb FAR * bpbp, REG struct dpb FAR * dpbp)
#ifdef WITHFAT32
if (extended)
{
dpbp->dpb_xfatsize = bpbp->bpb_nfsect == 0 ? bpbp->bpb_xnfsect
: bpbp->bpb_nfsect;
dpbp->dpb_xfatsize = sbpb.bpb_nfsect == 0 ? sbpb.bpb_xnfsect
: sbpb.bpb_nfsect;
dpbp->dpb_xcluster = UNKNCLUSTER;
dpbp->dpb_xnfreeclst = XUNKNCLSTFREE; /* number of free clusters */
@ -2025,16 +2046,16 @@ VOID bpb_to_dpb(bpb FAR * bpbp, REG struct dpb FAR * dpbp)
if (ISFAT32(dpbp))
{
dpbp->dpb_xflags = bpbp->bpb_xflags;
dpbp->dpb_xfsinfosec = bpbp->bpb_xfsinfosec;
dpbp->dpb_xbackupsec = bpbp->bpb_xbackupsec;
dpbp->dpb_xflags = sbpb.bpb_xflags;
dpbp->dpb_xfsinfosec = sbpb.bpb_xfsinfosec;
dpbp->dpb_xbackupsec = sbpb.bpb_xbackupsec;
dpbp->dpb_dirents = 0;
dpbp->dpb_dirstrt = 0xffff;
dpbp->dpb_size = 0;
dpbp->dpb_xdata =
dpbp->dpb_fatstrt + dpbp->dpb_fats * dpbp->dpb_xfatsize;
dpbp->dpb_xsize = ((size - dpbp->dpb_xdata) >> shftcnt) + 1;
dpbp->dpb_xrootclst = bpbp->bpb_xrootclst;
dpbp->dpb_xrootclst = sbpb.bpb_xrootclst;
read_fsinfo(dpbp);
}
}