1 /* 2 * linux/fs/isofs/dir.c 3 * 4 * (C) 1992, 1993, 1994 Eric Youngdale Modified for ISO 9660 filesystem. 5 * 6 * (C) 1991 Linus Torvalds - minix filesystem 7 * 8 * Steve Beynon : Missing last directory entries fixed 9 * (stephen@askone.demon.co.uk) : 21st June 1996 10 * 11 * isofs directory handling functions 12 */ 13 #include <linux/config.h> 14 #include <linux/smp_lock.h> 15 #include "isofs.h" 16 17 static int isofs_readdir(struct file *, void *, filldir_t); 18 19 struct file_operations isofs_dir_operations = 20 { 21 .read = generic_read_dir, 22 .readdir = isofs_readdir, 23 }; 24 25 /* 26 * directories can handle most operations... 27 */ 28 struct inode_operations isofs_dir_inode_operations = 29 { 30 .lookup = isofs_lookup, 31 }; 32 33 int isofs_name_translate(struct iso_directory_record *de, char *new, struct inode *inode) 34 { 35 char * old = de->name; 36 int len = de->name_len[0]; 37 int i; 38 39 for (i = 0; i < len; i++) { 40 unsigned char c = old[i]; 41 if (!c) 42 break; 43 44 if (c >= 'A' && c <= 'Z') 45 c |= 0x20; /* lower case */ 46 47 /* Drop trailing '.;1' (ISO 9660:1988 7.5.1 requires period) */ 48 if (c == '.' && i == len - 3 && old[i + 1] == ';' && old[i + 2] == '1') 49 break; 50 51 /* Drop trailing ';1' */ 52 if (c == ';' && i == len - 2 && old[i + 1] == '1') 53 break; 54 55 /* Convert remaining ';' to '.' */ 56 /* Also '/' to '.' (broken Acorn-generated ISO9660 images) */ 57 if (c == ';' || c == '/') 58 c = '.'; 59 60 new[i] = c; 61 } 62 return i; 63 } 64 65 /* Acorn extensions written by Matthew Wilcox <willy@bofh.ai> 1998 */ 66 int get_acorn_filename(struct iso_directory_record * de, 67 char * retname, struct inode * inode) 68 { 69 int std; 70 unsigned char * chr; 71 int retnamlen = isofs_name_translate(de, retname, inode); 72 if (retnamlen == 0) return 0; 73 std = sizeof(struct iso_directory_record) + de->name_len[0]; 74 if (std & 1) std++; 75 if ((*((unsigned char *) de) - std) != 32) return retnamlen; 76 chr = ((unsigned char *) de) + std; 77 if (strncmp(chr, "ARCHIMEDES", 10)) return retnamlen; 78 if ((*retname == '_') && ((chr[19] & 1) == 1)) *retname = '!'; 79 if (((de->flags[0] & 2) == 0) && (chr[13] == 0xff) 80 && ((chr[12] & 0xf0) == 0xf0)) 81 { 82 retname[retnamlen] = ','; 83 sprintf(retname+retnamlen+1, "%3.3x", 84 ((chr[12] & 0xf) << 8) | chr[11]); 85 retnamlen += 4; 86 } 87 return retnamlen; 88 } 89 90 /* 91 * This should _really_ be cleaned up some day.. 92 */ 93 static int do_isofs_readdir(struct inode *inode, struct file *filp, 94 void *dirent, filldir_t filldir, 95 char * tmpname, struct iso_directory_record * tmpde) 96 { 97 unsigned long bufsize = ISOFS_BUFFER_SIZE(inode); 98 unsigned char bufbits = ISOFS_BUFFER_BITS(inode); 99 unsigned long block, offset, block_saved, offset_saved; 100 unsigned long inode_number = 0; /* Quiet GCC */ 101 struct buffer_head *bh = NULL; 102 int len; 103 int map; 104 int first_de = 1; 105 char *p = NULL; /* Quiet GCC */ 106 struct iso_directory_record *de; 107 struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb); 108 109 offset = filp->f_pos & (bufsize - 1); 110 block = filp->f_pos >> bufbits; 111 112 while (filp->f_pos < inode->i_size) { 113 int de_len; 114 115 if (!bh) { 116 bh = isofs_bread(inode, block); 117 if (!bh) 118 return 0; 119 } 120 121 de = (struct iso_directory_record *) (bh->b_data + offset); 122 123 de_len = *(unsigned char *) de; 124 125 /* If the length byte is zero, we should move on to the next 126 CDROM sector. If we are at the end of the directory, we 127 kick out of the while loop. */ 128 129 if (de_len == 0) { 130 brelse(bh); 131 bh = NULL; 132 filp->f_pos = (filp->f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1); 133 block = filp->f_pos >> bufbits; 134 offset = 0; 135 continue; 136 } 137 138 block_saved = block; 139 offset_saved = offset; 140 offset += de_len; 141 142 /* Make sure we have a full directory entry */ 143 if (offset >= bufsize) { 144 int slop = bufsize - offset + de_len; 145 memcpy(tmpde, de, slop); 146 offset &= bufsize - 1; 147 block++; 148 brelse(bh); 149 bh = NULL; 150 if (offset) { 151 bh = isofs_bread(inode, block); 152 if (!bh) 153 return 0; 154 memcpy((void *) tmpde + slop, bh->b_data, offset); 155 } 156 de = tmpde; 157 } 158 159 if (first_de) { 160 isofs_normalize_block_and_offset(de, 161 &block_saved, 162 &offset_saved); 163 inode_number = isofs_get_ino(block_saved, 164 offset_saved, 165 bufbits); 166 } 167 168 if (de->flags[-sbi->s_high_sierra] & 0x80) { 169 first_de = 0; 170 filp->f_pos += de_len; 171 continue; 172 } 173 first_de = 1; 174 175 /* Handle the case of the '.' directory */ 176 if (de->name_len[0] == 1 && de->name[0] == 0) { 177 if (filldir(dirent, ".", 1, filp->f_pos, inode->i_ino, DT_DIR) < 0) 178 break; 179 filp->f_pos += de_len; 180 continue; 181 } 182 183 len = 0; 184 185 /* Handle the case of the '..' directory */ 186 if (de->name_len[0] == 1 && de->name[0] == 1) { 187 inode_number = parent_ino(filp->f_dentry); 188 if (filldir(dirent, "..", 2, filp->f_pos, inode_number, DT_DIR) < 0) 189 break; 190 filp->f_pos += de_len; 191 continue; 192 } 193 194 /* Handle everything else. Do name translation if there 195 is no Rock Ridge NM field. */ 196 197 /* 198 * Do not report hidden files if so instructed, or associated 199 * files unless instructed to do so 200 */ 201 if ((sbi->s_hide == 'y' && 202 (de->flags[-sbi->s_high_sierra] & 1)) || 203 (sbi->s_showassoc =='n' && 204 (de->flags[-sbi->s_high_sierra] & 4))) { 205 filp->f_pos += de_len; 206 continue; 207 } 208 209 map = 1; 210 if (sbi->s_rock) { 211 len = get_rock_ridge_filename(de, tmpname, inode); 212 if (len != 0) { /* may be -1 */ 213 p = tmpname; 214 map = 0; 215 } 216 } 217 if (map) { 218 #ifdef CONFIG_JOLIET 219 if (sbi->s_joliet_level) { 220 len = get_joliet_filename(de, tmpname, inode); 221 p = tmpname; 222 } else 223 #endif 224 if (sbi->s_mapping == 'a') { 225 len = get_acorn_filename(de, tmpname, inode); 226 p = tmpname; 227 } else 228 if (sbi->s_mapping == 'n') { 229 len = isofs_name_translate(de, tmpname, inode); 230 p = tmpname; 231 } else { 232 p = de->name; 233 len = de->name_len[0]; 234 } 235 } 236 if (len > 0) { 237 if (filldir(dirent, p, len, filp->f_pos, inode_number, DT_UNKNOWN) < 0) 238 break; 239 } 240 filp->f_pos += de_len; 241 242 continue; 243 } 244 if (bh) brelse(bh); 245 return 0; 246 } 247 248 /* 249 * Handle allocation of temporary space for name translation and 250 * handling split directory entries.. The real work is done by 251 * "do_isofs_readdir()". 252 */ 253 static int isofs_readdir(struct file *filp, 254 void *dirent, filldir_t filldir) 255 { 256 int result; 257 char * tmpname; 258 struct iso_directory_record * tmpde; 259 struct inode *inode = filp->f_dentry->d_inode; 260 261 262 tmpname = (char *)__get_free_page(GFP_KERNEL); 263 if (tmpname == NULL) 264 return -ENOMEM; 265 266 lock_kernel(); 267 tmpde = (struct iso_directory_record *) (tmpname+1024); 268 269 result = do_isofs_readdir(inode, filp, dirent, filldir, tmpname, tmpde); 270 271 free_page((unsigned long) tmpname); 272 unlock_kernel(); 273 return result; 274 } 275