freebsd-skq/lib/libdisk/blocks.c
jkh 5b33a2af7c + add u_long sector_size to struct disk (documented in libdisk.3)
+ make Open_Disk sense the sector size by trying 512, 1024 and 2048
  in this order. This makes the kernel note that
  dscheck(cd1): bio_bcount 512 is not on a sector boundary (ssize 2048)
  dscheck(cd1): bio_bcount 1024 is not on a sector boundary (ssize 2048)
  if 2048 is the sector size. If this worries anyone: the message is from
  /usr/src/sys/kern/subr_diskslice.c and shutups are to be placed there.
+ Have read_block and write_block use an additional parameter, the
  sector size.
+ replace all barfout calls with return NULL, 0, __LINE__, etc.
  Note that this does NOT emit diagnostics. More often than not,
  you don't want library functions to scribble on stderr -- it may
  not even be available. The right thing is to propagate the error
  condition to upper management. The app should take care of errors.
+ use d1->sector_size instead of 512 in various places. I've left many
  places untouched, especially those writing MBRs. I simply added
  another arg hardcoded as 512. This is because I would not know what
  I'm doing... I felt this approach would be reasonably backward
  compatible and not introduce any new bugs in critical software.
  Famous last words. Messing with MBRs might soon put me in the same
  screwup meister category as, uh, never mind.  :-)
+ bump the max no of disks from 20 to 32 (due to PR 24503).

PR:		8434 / 8436 / 24503
Submitted by:	Jens Schweikhardt <schweikh@schweikhardt.net>
2001-05-13 20:08:54 +00:00

46 lines
1.1 KiB
C

/*
* ----------------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
* <phk@login.dknet.dk> wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you think
* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
* ----------------------------------------------------------------------------
*
* $FreeBSD$
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "libdisk.h"
void *
read_block(int fd, daddr_t block, u_long sector_size)
{
void *foo;
foo = malloc(sector_size);
if (!foo)
return NULL;
if (-1 == lseek(fd, (off_t)block * sector_size, SEEK_SET)) {
free (foo);
return NULL;
}
if (sector_size != read(fd, foo, sector_size)) {
free (foo);
return NULL;
}
return foo;
}
int
write_block(int fd, daddr_t block, void *foo, u_long sector_size)
{
if (-1 == lseek(fd, (off_t)block * sector_size, SEEK_SET))
return -1;
if (sector_size != write(fd, foo, sector_size))
return -1;
return 0;
}