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usb/disk: fixed offsets in read(ctl), bug in offset calculation

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This commit is contained in:
ment 2011-05-08 23:55:58 +02:00
parent 2330fdb537
commit 52c77e17ca
1 changed files with 21 additions and 3 deletions
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24
sys/src/cmd/usb/disk/disk.c
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@ -108,6 +108,24 @@ delpart(Umsc *lun, char *s)
return 0;
}
void
fixlength(Umsc *lun, vlong blocks)
{
Part *part, *p;
part = lun->part;
part[Qdata].length = blocks;
for(p=&part[Qdata+1]; p < &part[Qmax]; p++){
if(p->inuse && p->offset + p->length > blocks){
if(p->offset > blocks){
p->offset =blocks;
p->length = 0;
}else
p->length = blocks - p->offset;
}
}
}
void
makeparts(Umsc *lun)
{
@ -143,7 +161,7 @@ ctlstring(Usbfs *fs)
for (p = &part[Qdata+1]; p < &part[Qmax]; p++)
if (p->inuse)
fmtprint(&fmt, "part %s %lld %lld\n",
p->name, p->offset, p->length);
p->name, p->offset, p->offset + p->length);
return fmtstrflush(&fmt);
}
@ -296,7 +314,7 @@ umscapacity(Umsc *lun)
}
lun->blocks++; /* SRcapacity returns LBA of last block */
lun->capacity = (vlong)lun->blocks * lun->lbsize;
lun->part[Qdata].length = lun->blocks;
fixlength(lun, lun->blocks);
if(diskdebug)
fprint(2, "disk: logical block size %lud, # blocks %llud\n",
lun->lbsize, lun->blocks);
@ -583,7 +601,6 @@ setup(Umsc *lun, Part *p, char *data, int count, vlong offset)
bno = offset >> lbshift; /* offset / lbsize */
nb = ((offset + count + lbsize - 1) >> lbshift) - bno;
bno += p->offset; /* start of partition */
if(bno + nb > p->length) /* past end of partition? */
nb = p->length - bno;
@ -593,6 +610,7 @@ setup(Umsc *lun, Part *p, char *data, int count, vlong offset)
if(bno >= p->length || nb == 0)
return 0;
bno += p->offset; /* start of partition */
lun->offset = bno;
lun->off = offset & lbmask; /* offset % lbsize */
if(lun->off == 0 && (count & lbmask) == 0)