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 if (sbi->s_unhide == 'n') { 197 /* Do not report hidden or associated files */ 198 if (de->flags[-sbi->s_high_sierra] & 5) { 199 filp->f_pos += de_len; 200 continue; 201 } 202 } 203 204 map = 1; 205 if (sbi->s_rock) { 206 len = get_rock_ridge_filename(de, tmpname, inode); 207 if (len != 0) { /* may be -1 */ 208 p = tmpname; 209 map = 0; 210 } 211 } 212 if (map) { 213 #ifdef CONFIG_JOLIET 214 if (sbi->s_joliet_level) { 215 len = get_joliet_filename(de, tmpname, inode); 216 p = tmpname; 217 } else 218 #endif 219 if (sbi->s_mapping == 'a') { 220 len = get_acorn_filename(de, tmpname, inode); 221 p = tmpname; 222 } else 223 if (sbi->s_mapping == 'n') { 224 len = isofs_name_translate(de, tmpname, inode); 225 p = tmpname; 226 } else { 227 p = de->name; 228 len = de->name_len[0]; 229 } 230 } 231 if (len > 0) { 232 if (filldir(dirent, p, len, filp->f_pos, inode_number, DT_UNKNOWN) < 0) 233 break; 234 } 235 filp->f_pos += de_len; 236 237 continue; 238 } 239 if (bh) brelse(bh); 240 return 0; 241 } 242 243 /* 244 * Handle allocation of temporary space for name translation and 245 * handling split directory entries.. The real work is done by 246 * "do_isofs_readdir()". 247 */ 248 static int isofs_readdir(struct file *filp, 249 void *dirent, filldir_t filldir) 250 { 251 int result; 252 char * tmpname; 253 struct iso_directory_record * tmpde; 254 struct inode *inode = filp->f_dentry->d_inode; 255 256 257 tmpname = (char *)__get_free_page(GFP_KERNEL); 258 if (tmpname == NULL) 259 return -ENOMEM; 260 261 lock_kernel(); 262 tmpde = (struct iso_directory_record *) (tmpname+1024); 263 264 result = do_isofs_readdir(inode, filp, dirent, filldir, tmpname, tmpde); 265 266 free_page((unsigned long) tmpname); 267 unlock_kernel(); 268 return result; 269 } 270