/* $OpenBSD: rawfs.c,v 1.3 2002/03/14 01:26:47 millert Exp $ */ /* $NetBSD: rawfs.c,v 1.1 1995/10/17 22:58:27 gwr 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 #include #include extern int debug; /* Our devices are generally willing to do 8K transfers. */ #define RAWFS_BSIZE 0x2000 /* * In-core open file. */ struct 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(struct open_file *); int rawfs_open(path, f) char *path; struct open_file *f; { struct file *fs; /* * The actual PROM driver has already been opened. * Just allocate the I/O buffer, etc. */ fs = alloc(sizeof(struct 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", fs); #endif f->f_fsdata = fs; return (0); } int rawfs_close(f) struct open_file *f; { struct file *fs; fs = (struct file *) f->f_fsdata; f->f_fsdata = (void *)0; #ifdef DEBUG_RAWFS if (debug) { printf("rawfs_close: breakpoint...", fs->fs_buf); __asm (" trap #0"); } #endif if (fs != (struct 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 file *fs = (struct file *)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 */ { #ifdef DEBUG_RAWFS panic("rawfs_write"); #endif return (EROFS); } off_t rawfs_seek(f, offset, where) struct open_file *f; off_t offset; int where; { #ifdef DEBUG_RAWFS panic("rawfs_seek"); #endif return (EFTYPE); } int rawfs_stat(f, sb) struct open_file *f; struct stat *sb; { #ifdef DEBUG_RAWFS panic("rawfs_stat"); #endif 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 file *fs; int error, len; fs = (struct file *)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); }