rawfs.c revision 1.1
1 /* $NetBSD: rawfs.c,v 1.1 1997/02/04 03:52:46 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1995 Gordon W. Ross 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 4. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by Gordon W. Ross 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * Raw file system - for stream devices like tapes. 35 * No random access, only sequential read allowed. 36 * This exists only to allow upper level code to be 37 * shielded from the fact that the device must be 38 * read only with whole block position and size. 39 */ 40 41 #include <sys/param.h> 42 43 #include <lib/libsa/stand.h> 44 #include <hp300/stand/common/rawfs.h> 45 46 extern int debug; 47 48 /* Our devices are generally willing to do 8K transfers. */ 49 #define RAWFS_BSIZE 0x2000 50 51 /* 52 * In-core open file. 53 */ 54 struct rawfs_file { 55 daddr_t fs_nextblk; /* block number to read next */ 56 int fs_len; /* amount left in f_buf */ 57 char * fs_ptr; /* read pointer into f_buf */ 58 char fs_buf[RAWFS_BSIZE]; 59 }; 60 61 static int 62 rawfs_get_block __P((struct open_file *)); 63 64 int 65 rawfs_open(path, f) 66 char *path; 67 struct open_file *f; 68 { 69 struct rawfs_file *fs; 70 71 /* 72 * The actual tape driver has already been opened. 73 * Just allocate the I/O buffer, etc. 74 */ 75 fs = alloc(sizeof(struct rawfs_file)); 76 fs->fs_nextblk = 0; 77 fs->fs_len = 0; 78 fs->fs_ptr = fs->fs_buf; 79 80 #ifdef DEBUG_RAWFS 81 printf("rawfs_open: fs=0x%x\n", (u_long)fs); 82 #endif 83 84 f->f_fsdata = fs; 85 return (0); 86 } 87 88 int 89 rawfs_close(f) 90 struct open_file *f; 91 { 92 struct rawfs_file *fs; 93 94 fs = (struct rawfs_file *) f->f_fsdata; 95 f->f_fsdata = (void *)0; 96 97 #ifdef DEBUG_RAWFS 98 printf("rawfs_close: fs=0x%x\n", (u_long)fs); 99 #endif 100 101 if (fs != (struct rawfs_file *)0) 102 free(fs, sizeof(*fs)); 103 104 return (0); 105 } 106 107 int 108 rawfs_read(f, start, size, resid) 109 struct open_file *f; 110 void *start; 111 u_int size; 112 u_int *resid; 113 { 114 struct rawfs_file *fs = (struct rawfs_file *)f->f_fsdata; 115 char *addr = start; 116 int error = 0; 117 size_t csize; 118 119 #ifdef DEBUG_RAWFS 120 printf("rawfs_read: file=0x%x, start=0x%x, size=%d, resid=0x%x\n", 121 (u_long)f, (u_long)start, size, resid); 122 printf(" fs=0x%x\n", (u_long)fs); 123 #endif 124 125 while (size != 0) { 126 127 if (fs->fs_len == 0) 128 if ((error = rawfs_get_block(f)) != 0) 129 break; 130 131 if (fs->fs_len <= 0) 132 break; /* EOF */ 133 134 csize = size; 135 if (csize > fs->fs_len) 136 csize = fs->fs_len; 137 138 bcopy(fs->fs_ptr, addr, csize); 139 fs->fs_ptr += csize; 140 fs->fs_len -= csize; 141 addr += csize; 142 size -= csize; 143 } 144 if (resid) 145 *resid = size; 146 return (error); 147 } 148 149 int 150 rawfs_write(f, start, size, resid) 151 struct open_file *f; 152 void *start; 153 size_t size; 154 size_t *resid; /* out */ 155 { 156 #ifdef DEBUG_RAWFS 157 printf("rawfs_write: YOU'RE NOT SUPPOSED TO GET HERE!\n"); 158 #endif 159 return (EROFS); 160 } 161 162 off_t 163 rawfs_seek(f, offset, where) 164 struct open_file *f; 165 off_t offset; 166 int where; 167 { 168 #ifdef DEBUG_RAWFS 169 printf("rawfs_seek: YOU'RE NOT SUPPOSED TO GET HERE!\n"); 170 #endif 171 return (EFTYPE); 172 } 173 174 int 175 rawfs_stat(f, sb) 176 struct open_file *f; 177 struct stat *sb; 178 { 179 #ifdef DEBUG_RAWFS 180 printf("rawfs_stat: I'll let you live only because of exec.c\n"); 181 #endif 182 /* 183 * Clear out the stat buffer so that the uid check 184 * won't fail. See sys/lib/libsa/exec.c 185 */ 186 bzero(sb, sizeof(*sb)); 187 188 return (EFTYPE); 189 } 190 191 /* 192 * Read a block from the underlying stream device 193 * (In our case, a tape drive.) 194 */ 195 static int 196 rawfs_get_block(f) 197 struct open_file *f; 198 { 199 struct rawfs_file *fs; 200 int error, len; 201 202 fs = (struct rawfs_file *)f->f_fsdata; 203 fs->fs_ptr = fs->fs_buf; 204 205 twiddle(); 206 #ifdef DEBUG_RAWFS 207 printf("rawfs_get_block: calling strategy\n"); 208 #endif 209 error = f->f_dev->dv_strategy(f->f_devdata, F_READ, 210 fs->fs_nextblk, RAWFS_BSIZE, fs->fs_buf, &len); 211 #ifdef DEBUG_RAWFS 212 printf("rawfs_get_block: strategy returned %d\n", error); 213 #endif 214 215 if (!error) { 216 fs->fs_len = len; 217 fs->fs_nextblk += (RAWFS_BSIZE / DEV_BSIZE); 218 } 219 220 return (error); 221 } 222
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