Patch for sd.c

H.J. Lu (hjl@lucon.org)
Thu, 11 Apr 1996 00:10:35 -0700 (PDT)

Hi,

Here is a patch for drivers/scsi/sd.c to fix the overflow
bug.

-- 
H.J. Lu (hjl@gnu.ai.mit.edu)

---
Index: sd.c
===================================================================
RCS file: /home/cvs/linux/linux/drivers/scsi/sd.c,v
retrieving revision 1.1.1.11
diff -c -r1.1.1.11 sd.c
*** sd.c	1996/04/11 05:46:39	1.1.1.11
--- sd.c	1996/04/11 06:59:28
***************
*** 1161,1174 ****
  	 * So I have created this table. See ll_rw_blk.c
  	 * Jacques Gelinas (Jacques@solucorp.qc.ca)
  	 */
! 	int m, mb;
          int sz_quot, sz_rem;
  	int hard_sector = rscsi_disks[i].sector_size;
  	/* There are 16 minors allocated for each major device */
  	for (m=i<<4; m<((i+1)<<4); m++){
  	    sd_hardsizes[m] = hard_sector;
  	}
!         mb = (hard_sector * rscsi_disks[i].capacity) / (1024*1024);
          /* sz = div(m/100, 10);  this seems to not be in the libr */
          m = (mb + 50) / 100;
          sz_quot = m / 10;
--- 1161,1190 ----
  	 * So I have created this table. See ll_rw_blk.c
  	 * Jacques Gelinas (Jacques@solucorp.qc.ca)
  	 */
! 	int m, mb, one_mb;
          int sz_quot, sz_rem;
  	int hard_sector = rscsi_disks[i].sector_size;
  	/* There are 16 minors allocated for each major device */
  	for (m=i<<4; m<((i+1)<<4); m++){
  	    sd_hardsizes[m] = hard_sector;
  	}
! 	/*
!          * mb = (hard_sector * rscsi_disks[i].capacity) / (1024*1024);
! 	 *
! 	 * hard_sector * rscsi_disks[i].capacity may be overflow.
! 	 * We should be very careful. 1 MB is 1 << 20.
! 	 * H.J. (hjl@lucon.org).
! 	 */
! 	one_mb = 20;
! 	for (mb = hard_sector; (mb & 0x1) == 0 && one_mb > 0;
! 		mb >>= 1, one_mb--);
! 	for (mb *= rscsi_disks[i].capacity;
! 		(mb & 0x1) == 0 && one_mb > 0;
! 		mb >>= 1, one_mb--);
! 	if (one_mb > 0)
! 	{
! 	  mb >>= one_mb;
! 	}
          /* sz = div(m/100, 10);  this seems to not be in the libr */
          m = (mb + 50) / 100;
          sz_quot = m / 10;