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/* $OpenBSD: rawfs.c,v 1.4 2006/05/16 22:52:09 miod Exp $ */
/*
* Copyright (c) 1995 Gordon W. Ross
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
* 4. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Gordon W. Ross
*
* 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.
*/
/*
* Raw file system - for stream devices like tapes.
* No random access, only sequential read allowed.
* This exists only to allow upper level code to be
* shielded from the fact that the device must be
* read only with whole block position and size.
*/
#include <sys/param.h>
#include <stand.h>
#include <rawfs.h>
#define RAWFS_BSIZE 512
/*
* In-core open file.
*/
struct cfile {
daddr_t fs_nextblk; /* block number to read next */
int fs_len; /* amount left in f_buf */
char * fs_ptr; /* read pointer into f_buf */
char fs_buf[RAWFS_BSIZE];
};
static int
rawfs_get_block(struct open_file *);
int rawfs_open(path, f)
char *path;
struct open_file *f;
{
struct cfile *fs;
/*
* The actual PROM driver has already been opened.
* Just allocate the I/O buffer, etc.
*/
fs = alloc(sizeof(struct cfile));
fs->fs_nextblk = 0;
fs->fs_len = 0;
fs->fs_ptr = fs->fs_buf;
f->f_fsdata = fs;
return (0);
}
int rawfs_close(f)
struct open_file *f;
{
struct cfile *fs;
fs = (struct cfile *) f->f_fsdata;
f->f_fsdata = (void *)0;
if (fs != (struct cfile *)0)
free(fs, sizeof(*fs));
return (0);
}
int rawfs_read(f, start, size, resid)
struct open_file *f;
void *start;
size_t size;
size_t *resid;
{
struct cfile *fs = (struct cfile *)f->f_fsdata;
char *addr = start;
int error = 0;
size_t csize;
while (size != 0) {
if (fs->fs_len == 0)
if ((error = rawfs_get_block(f)) != 0)
break;
if (fs->fs_len <= 0)
break; /* EOF */
csize = size;
if (csize > fs->fs_len)
csize = fs->fs_len;
bcopy(fs->fs_ptr, addr, csize);
fs->fs_ptr += csize;
fs->fs_len -= csize;
addr += csize;
size -= csize;
}
if (resid)
*resid = size;
return (error);
}
int rawfs_write(f, start, size, resid)
struct open_file *f;
void *start;
size_t size;
size_t *resid; /* out */
{
return (EROFS);
}
off_t rawfs_seek(f, offset, where)
struct open_file *f;
off_t offset;
int where;
{
return (EFTYPE);
}
int rawfs_stat(f, sb)
struct open_file *f;
struct stat *sb;
{
return (EFTYPE);
}
/*
* Read a block from the underlying stream device
* (In our case, a tape drive.)
*/
static int
rawfs_get_block(f)
struct open_file *f;
{
struct cfile *fs;
int error;
size_t len;
fs = (struct cfile *)f->f_fsdata;
fs->fs_ptr = fs->fs_buf;
twiddle();
error = f->f_dev->dv_strategy(f->f_devdata, F_READ,
fs->fs_nextblk, RAWFS_BSIZE, fs->fs_buf, &len);
if (!error) {
fs->fs_len = len;
fs->fs_nextblk += (RAWFS_BSIZE / DEV_BSIZE);
}
return (error);
}
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