rawfs.c revision 1.3
1 /* $NetBSD: rawfs.c,v 1.3 2003/11/14 16:52:40 tsutsui 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 rawfs_get_block(struct open_file *); 62 63 int 64 rawfs_open(path, f) 65 const char *path; 66 struct open_file *f; 67 { 68 struct rawfs_file *fs; 69 70 /* 71 * The actual tape driver has already been opened. 72 * Just allocate the I/O buffer, etc. 73 */ 74 fs = alloc(sizeof(struct rawfs_file)); 75 fs->fs_nextblk = 0; 76 fs->fs_len = 0; 77 fs->fs_ptr = fs->fs_buf; 78 79 #ifdef DEBUG_RAWFS 80 printf("rawfs_open: fs=0x%x\n", (u_long)fs); 81 #endif 82 83 f->f_fsdata = fs; 84 return 0; 85 } 86 87 int 88 rawfs_close(f) 89 struct open_file *f; 90 { 91 struct rawfs_file *fs; 92 93 fs = (struct rawfs_file *) f->f_fsdata; 94 f->f_fsdata = (void *)0; 95 96 #ifdef DEBUG_RAWFS 97 printf("rawfs_close: fs=0x%x\n", (u_long)fs); 98 #endif 99 100 if (fs != (struct rawfs_file *)0) 101 free(fs, sizeof(*fs)); 102 103 return 0; 104 } 105 106 int 107 rawfs_read(f, start, size, resid) 108 struct open_file *f; 109 void *start; 110 u_int size; 111 u_int *resid; 112 { 113 struct rawfs_file *fs = (struct rawfs_file *)f->f_fsdata; 114 char *addr = start; 115 int error = 0; 116 size_t csize; 117 118 #ifdef DEBUG_RAWFS 119 printf("rawfs_read: file=0x%x, start=0x%x, size=%d, resid=0x%x\n", 120 (u_long)f, (u_long)start, size, resid); 121 printf(" fs=0x%x\n", (u_long)fs); 122 #endif 123 124 while (size != 0) { 125 126 if (fs->fs_len == 0) 127 if ((error = rawfs_get_block(f)) != 0) 128 break; 129 130 if (fs->fs_len <= 0) 131 break; /* EOF */ 132 133 csize = size; 134 if (csize > fs->fs_len) 135 csize = fs->fs_len; 136 137 memcpy(addr, fs->fs_ptr, csize); 138 fs->fs_ptr += csize; 139 fs->fs_len -= csize; 140 addr += csize; 141 size -= csize; 142 } 143 if (resid) 144 *resid = size; 145 return error; 146 } 147 148 int 149 rawfs_write(f, start, size, resid) 150 struct open_file *f; 151 void *start; 152 size_t size; 153 size_t *resid; /* out */ 154 { 155 #ifdef DEBUG_RAWFS 156 printf("rawfs_write: YOU'RE NOT SUPPOSED TO GET HERE!\n"); 157 #endif 158 return EROFS; 159 } 160 161 off_t 162 rawfs_seek(f, offset, where) 163 struct open_file *f; 164 off_t offset; 165 int where; 166 { 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 { 179 180 #ifdef DEBUG_RAWFS 181 printf("rawfs_stat: I'll let you live only because of exec.c\n"); 182 #endif 183 /* 184 * Clear out the stat buffer so that the uid check 185 * won't fail. See sys/lib/libsa/exec.c 186 */ 187 memset(sb, 0, sizeof(*sb)); 188 189 return EFTYPE; 190 } 191 192 /* 193 * Read a block from the underlying stream device 194 * (In our case, a tape drive.) 195 */ 196 static int 197 rawfs_get_block(f) 198 struct open_file *f; 199 { 200 struct rawfs_file *fs; 201 int error, len; 202 203 fs = (struct rawfs_file *)f->f_fsdata; 204 fs->fs_ptr = fs->fs_buf; 205 206 twiddle(); 207 #ifdef DEBUG_RAWFS 208 printf("rawfs_get_block: calling strategy\n"); 209 #endif 210 error = f->f_dev->dv_strategy(f->f_devdata, F_READ, 211 fs->fs_nextblk, RAWFS_BSIZE, fs->fs_buf, &len); 212 #ifdef DEBUG_RAWFS 213 printf("rawfs_get_block: strategy returned %d\n", error); 214 #endif 215 216 if (!error) { 217 fs->fs_len = len; 218 fs->fs_nextblk += (RAWFS_BSIZE / DEV_BSIZE); 219 } 220 221 return error; 222 } 223
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