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Clean up bounds_check_with_label(). Round request to sector size in label,

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and return EINVAL if bcount is less than the sector size or negative.
This commit is contained in:
mycroft 1995-01-13 06:51:38 +00:00
parent 002aa598e1
commit dc63598a7f
1 changed files with 38 additions and 38 deletions
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74
sys/arch/i386/i386/disksubr.c
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@ -1,4 +1,4 @@
/* $NetBSD: disksubr.c,v 1.14 1994/12/14 15:17:22 mycroft Exp $ */
/* $NetBSD: disksubr.c,v 1.15 1995/01/13 06:51:38 mycroft Exp $ */
/*
* Copyright (c) 1982, 1986, 1988 Regents of the University of California.
@ -352,55 +352,55 @@ done:
* if needed, and signal errors or early completion.
*/
int
bounds_check_with_label(struct buf *bp, struct disklabel *lp, int wlabel)
bounds_check_with_label(bp, lp, wlabel)
struct buf *bp;
struct disklabel *lp;
int wlabel;
{
struct partition *p = lp->d_partitions + DISKPART(bp->b_dev);
int labelsect = lp->d_partitions[0].p_offset;
int maxsz = p->p_size,
sz = (bp->b_bcount + DEV_BSIZE - 1) >> DEV_BSHIFT;
int labelsect = lp->d_partitions[2].p_offset + LABELSECTOR;
int sz;
/* overwriting disk label ? */
/* XXX should also protect bootstrap in first 8K */
if (bp->b_blkno + p->p_offset <= LABELSECTOR + labelsect &&
#if LABELSECTOR != 0
bp->b_blkno + p->p_offset + sz > LABELSECTOR + labelsect &&
#endif
(bp->b_flags & B_READ) == 0 && wlabel == 0) {
bp->b_error = EROFS;
goto bad;
}
#if defined(DOSBBSECTOR) && defined(notyet)
/* overwriting master boot record? */
if (bp->b_blkno + p->p_offset <= DOSBBSECTOR &&
(bp->b_flags & B_READ) == 0 && wlabel == 0) {
bp->b_error = EROFS;
goto bad;
}
#endif
/* beyond partition? */
if (bp->b_blkno < 0 || bp->b_blkno + sz > maxsz) {
/* if exactly at end of disk, return an EOF */
if (bp->b_blkno == maxsz) {
bp->b_resid = bp->b_bcount;
return(0);
}
/* or truncate if part of it fits */
sz = maxsz - bp->b_blkno;
if (sz <= 0) {
if (bp->b_bcount < lp->d_secsize) {
/* No whole sectors requested. */
bp->b_error = EINVAL;
goto bad;
}
sz = (bp->b_bcount + lp->d_secsize - 1) / lp->d_secsize;
/* Overwriting disk label? */
/* XXX Also protect MBR and boot program? */
if (bp->b_blkno + p->p_offset <= labelsect &&
#if LABELSECTOR != 0
bp->b_blkno + p->p_offset + sz > labelsect &&
#endif
(bp->b_flags & B_READ) == 0 && wlabel == 0) {
bp->b_error = EROFS;
goto bad;
}
if (bp->b_blkno + sz > p->p_size) {
sz = p->p_size - bp->b_blkno;
if (sz == 0) {
/* If exactly at end of disk, return EOF. */
bp->b_resid = bp->b_bcount;
return (0);
if (sz < 0) {
/* If past end of disk, return EINVAL. */
bp->b_error = EINVAL;
goto bad;
}
/* Otherwise, truncate request. */
bp->b_bcount = sz << DEV_BSHIFT;
}
/* calculate cylinder for disksort to order transfers with */
bp->b_cylin = (bp->b_blkno + p->p_offset) / lp->d_secpercyl;
return(1);
return (1);
bad:
bp->b_flags |= B_ERROR;
return(-1);
return (-1);
}