freebsd-nq/lib/libufs/block.c
2003-03-30 18:00:24 +00:00

105 lines
2.8 KiB
C

/*
* Copyright (c) 2002 Juli Mallett. All rights reserved.
*
* This software was written by Juli Mallett <jmallett@FreeBSD.org> for the
* FreeBSD project. Redistribution and use in source and binary forms, with
* or without modification, are permitted provided that the following
* conditions are met:
*
* 1. Redistribution of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistribution in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/disklabel.h>
#include <sys/stat.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/dinode.h>
#include <ufs/ffs/fs.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <libufs.h>
ssize_t
bread(struct uufsd *disk, ufs2_daddr_t blockno, void *data, size_t size)
{
char *buf;
ssize_t cnt;
ERROR(disk, NULL);
/*
* For when we need to work with the data as a buffer.
*/
buf = data;
cnt = pread(disk->d_fd, data, size, (off_t)(blockno * disk->d_bsize));
if (cnt == -1) {
ERROR(disk, "read error from block device");
goto fail;
}
if (cnt == 0) {
ERROR(disk, "end of file from block device");
goto fail;
}
if ((size_t)cnt != size) {
ERROR(disk, "short read or read error from block device");
goto fail;
}
return cnt;
fail: memset(buf, 0, size);
return -1;
}
ssize_t
bwrite(struct uufsd *disk, ufs2_daddr_t blockno, const void *data, size_t size)
{
ssize_t cnt;
int rv;
ERROR(disk, NULL);
rv = ufs_disk_write(disk);
if (rv == -1) {
ERROR(disk, "failed to open disk for writing");
return -1;
}
cnt = pwrite(disk->d_fd, data, size, (off_t)(blockno * disk->d_bsize));
if (cnt == -1) {
ERROR(disk, "write error to block device");
return -1;
}
if ((size_t)cnt != size) {
ERROR(disk, "short write to block device");
return -1;
}
return cnt;
}