NetBSD/sys/arch/hp300/stand/common/rawfs.c

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/* $NetBSD: rawfs.c,v 1.1 1997/02/04 03:52:46 thorpej 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 <lib/libsa/stand.h>
#include <hp300/stand/common/rawfs.h>
extern int debug;
/* Our devices are generally willing to do 8K transfers. */
#define RAWFS_BSIZE 0x2000
/*
* In-core open file.
*/
struct rawfs_file {
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 __P((struct open_file *));
int
rawfs_open(path, f)
char *path;
struct open_file *f;
{
struct rawfs_file *fs;
/*
* The actual tape driver has already been opened.
* Just allocate the I/O buffer, etc.
*/
fs = alloc(sizeof(struct rawfs_file));
fs->fs_nextblk = 0;
fs->fs_len = 0;
fs->fs_ptr = fs->fs_buf;
#ifdef DEBUG_RAWFS
printf("rawfs_open: fs=0x%x\n", (u_long)fs);
#endif
f->f_fsdata = fs;
return (0);
}
int
rawfs_close(f)
struct open_file *f;
{
struct rawfs_file *fs;
fs = (struct rawfs_file *) f->f_fsdata;
f->f_fsdata = (void *)0;
#ifdef DEBUG_RAWFS
printf("rawfs_close: fs=0x%x\n", (u_long)fs);
#endif
if (fs != (struct rawfs_file *)0)
free(fs, sizeof(*fs));
return (0);
}
int
rawfs_read(f, start, size, resid)
struct open_file *f;
void *start;
u_int size;
u_int *resid;
{
struct rawfs_file *fs = (struct rawfs_file *)f->f_fsdata;
char *addr = start;
int error = 0;
size_t csize;
#ifdef DEBUG_RAWFS
printf("rawfs_read: file=0x%x, start=0x%x, size=%d, resid=0x%x\n",
(u_long)f, (u_long)start, size, resid);
printf(" fs=0x%x\n", (u_long)fs);
#endif
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 */
{
#ifdef DEBUG_RAWFS
printf("rawfs_write: YOU'RE NOT SUPPOSED TO GET HERE!\n");
#endif
return (EROFS);
}
off_t
rawfs_seek(f, offset, where)
struct open_file *f;
off_t offset;
int where;
{
#ifdef DEBUG_RAWFS
printf("rawfs_seek: YOU'RE NOT SUPPOSED TO GET HERE!\n");
#endif
return (EFTYPE);
}
int
rawfs_stat(f, sb)
struct open_file *f;
struct stat *sb;
{
#ifdef DEBUG_RAWFS
printf("rawfs_stat: I'll let you live only because of exec.c\n");
#endif
/*
* Clear out the stat buffer so that the uid check
* won't fail. See sys/lib/libsa/exec.c
*/
bzero(sb, sizeof(*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 rawfs_file *fs;
int error, len;
fs = (struct rawfs_file *)f->f_fsdata;
fs->fs_ptr = fs->fs_buf;
twiddle();
#ifdef DEBUG_RAWFS
printf("rawfs_get_block: calling strategy\n");
#endif
error = f->f_dev->dv_strategy(f->f_devdata, F_READ,
fs->fs_nextblk, RAWFS_BSIZE, fs->fs_buf, &len);
#ifdef DEBUG_RAWFS
printf("rawfs_get_block: strategy returned %d\n", error);
#endif
if (!error) {
fs->fs_len = len;
fs->fs_nextblk += (RAWFS_BSIZE / DEV_BSIZE);
}
return (error);
}