rawfs.c revision 1.4
1 /* $NetBSD: rawfs.c,v 1.4 2005/02/20 13:59:27 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(const char *path, struct open_file *f) 65 { 66 struct rawfs_file *fs; 67 68 /* 69 * The actual tape driver has already been opened. 70 * Just allocate the I/O buffer, etc. 71 */ 72 fs = alloc(sizeof(struct rawfs_file)); 73 fs->fs_nextblk = 0; 74 fs->fs_len = 0; 75 fs->fs_ptr = fs->fs_buf; 76 77 #ifdef DEBUG_RAWFS 78 printf("rawfs_open: fs=0x%x\n", (u_long)fs); 79 #endif 80 81 f->f_fsdata = fs; 82 return 0; 83 } 84 85 int 86 rawfs_close(struct open_file *f) 87 { 88 struct rawfs_file *fs; 89 90 fs = (struct rawfs_file *) f->f_fsdata; 91 f->f_fsdata = (void *)0; 92 93 #ifdef DEBUG_RAWFS 94 printf("rawfs_close: fs=0x%x\n", (u_long)fs); 95 #endif 96 97 if (fs != (struct rawfs_file *)0) 98 free(fs, sizeof(*fs)); 99 100 return 0; 101 } 102 103 int 104 rawfs_read(struct open_file *f, void *start, u_int size, u_int *resid) 105 { 106 struct rawfs_file *fs = (struct rawfs_file *)f->f_fsdata; 107 char *addr = start; 108 int error = 0; 109 size_t csize; 110 111 #ifdef DEBUG_RAWFS 112 printf("rawfs_read: file=0x%x, start=0x%x, size=%d, resid=0x%x\n", 113 (u_long)f, (u_long)start, size, resid); 114 printf(" fs=0x%x\n", (u_long)fs); 115 #endif 116 117 while (size != 0) { 118 119 if (fs->fs_len == 0) 120 if ((error = rawfs_get_block(f)) != 0) 121 break; 122 123 if (fs->fs_len <= 0) 124 break; /* EOF */ 125 126 csize = size; 127 if (csize > fs->fs_len) 128 csize = fs->fs_len; 129 130 memcpy(addr, fs->fs_ptr, csize); 131 fs->fs_ptr += csize; 132 fs->fs_len -= csize; 133 addr += csize; 134 size -= csize; 135 } 136 if (resid) 137 *resid = size; 138 return error; 139 } 140 141 int 142 rawfs_write(struct open_file *f, void *start, size_t size, size_t *resid) 143 { 144 145 #ifdef DEBUG_RAWFS 146 printf("rawfs_write: YOU'RE NOT SUPPOSED TO GET HERE!\n"); 147 #endif 148 return EROFS; 149 } 150 151 off_t 152 rawfs_seek(struct open_file *f, off_t offset, int where) 153 { 154 155 #ifdef DEBUG_RAWFS 156 printf("rawfs_seek: YOU'RE NOT SUPPOSED TO GET HERE!\n"); 157 #endif 158 return EFTYPE; 159 } 160 161 int 162 rawfs_stat(struct open_file *f, struct stat *sb) 163 { 164 165 #ifdef DEBUG_RAWFS 166 printf("rawfs_stat: I'll let you live only because of exec.c\n"); 167 #endif 168 /* 169 * Clear out the stat buffer so that the uid check 170 * won't fail. See sys/lib/libsa/exec.c 171 */ 172 memset(sb, 0, sizeof(*sb)); 173 174 return EFTYPE; 175 } 176 177 /* 178 * Read a block from the underlying stream device 179 * (In our case, a tape drive.) 180 */ 181 static int 182 rawfs_get_block(struct open_file *f) 183 { 184 struct rawfs_file *fs; 185 int error, len; 186 187 fs = (struct rawfs_file *)f->f_fsdata; 188 fs->fs_ptr = fs->fs_buf; 189 190 twiddle(); 191 #ifdef DEBUG_RAWFS 192 printf("rawfs_get_block: calling strategy\n"); 193 #endif 194 error = f->f_dev->dv_strategy(f->f_devdata, F_READ, 195 fs->fs_nextblk, RAWFS_BSIZE, fs->fs_buf, &len); 196 #ifdef DEBUG_RAWFS 197 printf("rawfs_get_block: strategy returned %d\n", error); 198 #endif 199 200 if (!error) { 201 fs->fs_len = len; 202 fs->fs_nextblk += (RAWFS_BSIZE / DEV_BSIZE); 203 } 204 205 return error; 206 } 207
Indexes created Thu Oct 02 01:09:59 GMT 2025