1 /* 2 * linux/fs/hpfs/map.c 3 * 4 * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999 5 * 6 * mapping structures to memory with some minimal checks 7 */ 8 9 #include "hpfs_fn.h" 10 11 __le32 *hpfs_map_dnode_bitmap(struct super_block *s, struct quad_buffer_head *qbh) 12 { 13 return hpfs_map_4sectors(s, hpfs_sb(s)->sb_dmap, qbh, 0); 14 } 15 16 __le32 *hpfs_map_bitmap(struct super_block *s, unsigned bmp_block, 17 struct quad_buffer_head *qbh, char *id) 18 { 19 secno sec; 20 __le32 *ret; 21 unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14; 22 if (hpfs_sb(s)->sb_chk) if (bmp_block >= n_bands) { 23 hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id); 24 return NULL; 25 } 26 sec = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]); 27 if (!sec || sec > hpfs_sb(s)->sb_fs_size-4) { 28 hpfs_error(s, "invalid bitmap block pointer %08x -> %08x at %s", bmp_block, sec, id); 29 return NULL; 30 } 31 ret = hpfs_map_4sectors(s, sec, qbh, 4); 32 if (ret) hpfs_prefetch_bitmap(s, bmp_block + 1); 33 return ret; 34 } 35 36 void hpfs_prefetch_bitmap(struct super_block *s, unsigned bmp_block) 37 { 38 unsigned to_prefetch, next_prefetch; 39 unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14; 40 if (unlikely(bmp_block >= n_bands)) 41 return; 42 to_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]); 43 if (unlikely(bmp_block + 1 >= n_bands)) 44 next_prefetch = 0; 45 else 46 next_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block + 1]); 47 hpfs_prefetch_sectors(s, to_prefetch, 4 + 4 * (to_prefetch + 4 == next_prefetch)); 48 } 49 50 /* 51 * Load first code page into kernel memory, return pointer to 256-byte array, 52 * first 128 bytes are uppercasing table for chars 128-255, next 128 bytes are 53 * lowercasing table 54 */ 55 56 unsigned char *hpfs_load_code_page(struct super_block *s, secno cps) 57 { 58 struct buffer_head *bh; 59 secno cpds; 60 unsigned cpi; 61 unsigned char *ptr; 62 unsigned char *cp_table; 63 int i; 64 struct code_page_data *cpd; 65 struct code_page_directory *cp = hpfs_map_sector(s, cps, &bh, 0); 66 if (!cp) return NULL; 67 if (le32_to_cpu(cp->magic) != CP_DIR_MAGIC) { 68 printk("HPFS: Code page directory magic doesn't match (magic = %08x)\n", le32_to_cpu(cp->magic)); 69 brelse(bh); 70 return NULL; 71 } 72 if (!le32_to_cpu(cp->n_code_pages)) { 73 printk("HPFS: n_code_pages == 0\n"); 74 brelse(bh); 75 return NULL; 76 } 77 cpds = le32_to_cpu(cp->array[0].code_page_data); 78 cpi = le16_to_cpu(cp->array[0].index); 79 brelse(bh); 80 81 if (cpi >= 3) { 82 printk("HPFS: Code page index out of array\n"); 83 return NULL; 84 } 85 86 if (!(cpd = hpfs_map_sector(s, cpds, &bh, 0))) return NULL; 87 if (le16_to_cpu(cpd->offs[cpi]) > 0x178) { 88 printk("HPFS: Code page index out of sector\n"); 89 brelse(bh); 90 return NULL; 91 } 92 ptr = (unsigned char *)cpd + le16_to_cpu(cpd->offs[cpi]) + 6; 93 if (!(cp_table = kmalloc(256, GFP_KERNEL))) { 94 printk("HPFS: out of memory for code page table\n"); 95 brelse(bh); 96 return NULL; 97 } 98 memcpy(cp_table, ptr, 128); 99 brelse(bh); 100 101 /* Try to build lowercasing table from uppercasing one */ 102 103 for (i=128; i<256; i++) cp_table[i]=i; 104 for (i=128; i<256; i++) if (cp_table[i-128]!=i && cp_table[i-128]>=128) 105 cp_table[cp_table[i-128]] = i; 106 107 return cp_table; 108 } 109 110 __le32 *hpfs_load_bitmap_directory(struct super_block *s, secno bmp) 111 { 112 struct buffer_head *bh; 113 int n = (hpfs_sb(s)->sb_fs_size + 0x200000 - 1) >> 21; 114 int i; 115 __le32 *b; 116 if (!(b = kmalloc(n * 512, GFP_KERNEL))) { 117 printk("HPFS: can't allocate memory for bitmap directory\n"); 118 return NULL; 119 } 120 for (i=0;i<n;i++) { 121 __le32 *d = hpfs_map_sector(s, bmp+i, &bh, n - i - 1); 122 if (!d) { 123 kfree(b); 124 return NULL; 125 } 126 memcpy((char *)b + 512 * i, d, 512); 127 brelse(bh); 128 } 129 return b; 130 } 131 132 /* 133 * Load fnode to memory 134 */ 135 136 struct fnode *hpfs_map_fnode(struct super_block *s, ino_t ino, struct buffer_head **bhp) 137 { 138 struct fnode *fnode; 139 if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ino, 1, "fnode")) { 140 return NULL; 141 } 142 if ((fnode = hpfs_map_sector(s, ino, bhp, FNODE_RD_AHEAD))) { 143 if (hpfs_sb(s)->sb_chk) { 144 struct extended_attribute *ea; 145 struct extended_attribute *ea_end; 146 if (le32_to_cpu(fnode->magic) != FNODE_MAGIC) { 147 hpfs_error(s, "bad magic on fnode %08lx", 148 (unsigned long)ino); 149 goto bail; 150 } 151 if (!fnode_is_dir(fnode)) { 152 if ((unsigned)fnode->btree.n_used_nodes + (unsigned)fnode->btree.n_free_nodes != 153 (bp_internal(&fnode->btree) ? 12 : 8)) { 154 hpfs_error(s, 155 "bad number of nodes in fnode %08lx", 156 (unsigned long)ino); 157 goto bail; 158 } 159 if (le16_to_cpu(fnode->btree.first_free) != 160 8 + fnode->btree.n_used_nodes * (bp_internal(&fnode->btree) ? 8 : 12)) { 161 hpfs_error(s, 162 "bad first_free pointer in fnode %08lx", 163 (unsigned long)ino); 164 goto bail; 165 } 166 } 167 if (le16_to_cpu(fnode->ea_size_s) && (le16_to_cpu(fnode->ea_offs) < 0xc4 || 168 le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s) + le16_to_cpu(fnode->ea_size_s) > 0x200)) { 169 hpfs_error(s, 170 "bad EA info in fnode %08lx: ea_offs == %04x ea_size_s == %04x", 171 (unsigned long)ino, 172 le16_to_cpu(fnode->ea_offs), le16_to_cpu(fnode->ea_size_s)); 173 goto bail; 174 } 175 ea = fnode_ea(fnode); 176 ea_end = fnode_end_ea(fnode); 177 while (ea != ea_end) { 178 if (ea > ea_end) { 179 hpfs_error(s, "bad EA in fnode %08lx", 180 (unsigned long)ino); 181 goto bail; 182 } 183 ea = next_ea(ea); 184 } 185 } 186 } 187 return fnode; 188 bail: 189 brelse(*bhp); 190 return NULL; 191 } 192 193 struct anode *hpfs_map_anode(struct super_block *s, anode_secno ano, struct buffer_head **bhp) 194 { 195 struct anode *anode; 196 if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ano, 1, "anode")) return NULL; 197 if ((anode = hpfs_map_sector(s, ano, bhp, ANODE_RD_AHEAD))) 198 if (hpfs_sb(s)->sb_chk) { 199 if (le32_to_cpu(anode->magic) != ANODE_MAGIC) { 200 hpfs_error(s, "bad magic on anode %08x", ano); 201 goto bail; 202 } 203 if (le32_to_cpu(anode->self) != ano) { 204 hpfs_error(s, "self pointer invalid on anode %08x", ano); 205 goto bail; 206 } 207 if ((unsigned)anode->btree.n_used_nodes + (unsigned)anode->btree.n_free_nodes != 208 (bp_internal(&anode->btree) ? 60 : 40)) { 209 hpfs_error(s, "bad number of nodes in anode %08x", ano); 210 goto bail; 211 } 212 if (le16_to_cpu(anode->btree.first_free) != 213 8 + anode->btree.n_used_nodes * (bp_internal(&anode->btree) ? 8 : 12)) { 214 hpfs_error(s, "bad first_free pointer in anode %08x", ano); 215 goto bail; 216 } 217 } 218 return anode; 219 bail: 220 brelse(*bhp); 221 return NULL; 222 } 223 224 /* 225 * Load dnode to memory and do some checks 226 */ 227 228 struct dnode *hpfs_map_dnode(struct super_block *s, unsigned secno, 229 struct quad_buffer_head *qbh) 230 { 231 struct dnode *dnode; 232 if (hpfs_sb(s)->sb_chk) { 233 if (hpfs_chk_sectors(s, secno, 4, "dnode")) return NULL; 234 if (secno & 3) { 235 hpfs_error(s, "dnode %08x not byte-aligned", secno); 236 return NULL; 237 } 238 } 239 if ((dnode = hpfs_map_4sectors(s, secno, qbh, DNODE_RD_AHEAD))) 240 if (hpfs_sb(s)->sb_chk) { 241 unsigned p, pp = 0; 242 unsigned char *d = (unsigned char *)dnode; 243 int b = 0; 244 if (le32_to_cpu(dnode->magic) != DNODE_MAGIC) { 245 hpfs_error(s, "bad magic on dnode %08x", secno); 246 goto bail; 247 } 248 if (le32_to_cpu(dnode->self) != secno) 249 hpfs_error(s, "bad self pointer on dnode %08x self = %08x", secno, le32_to_cpu(dnode->self)); 250 /* Check dirents - bad dirents would cause infinite 251 loops or shooting to memory */ 252 if (le32_to_cpu(dnode->first_free) > 2048) { 253 hpfs_error(s, "dnode %08x has first_free == %08x", secno, le32_to_cpu(dnode->first_free)); 254 goto bail; 255 } 256 for (p = 20; p < le32_to_cpu(dnode->first_free); p += d[p] + (d[p+1] << 8)) { 257 struct hpfs_dirent *de = (struct hpfs_dirent *)((char *)dnode + p); 258 if (le16_to_cpu(de->length) > 292 || (le16_to_cpu(de->length) < 32) || (le16_to_cpu(de->length) & 3) || p + le16_to_cpu(de->length) > 2048) { 259 hpfs_error(s, "bad dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp); 260 goto bail; 261 } 262 if (((31 + de->namelen + de->down*4 + 3) & ~3) != le16_to_cpu(de->length)) { 263 if (((31 + de->namelen + de->down*4 + 3) & ~3) < le16_to_cpu(de->length) && s->s_flags & MS_RDONLY) goto ok; 264 hpfs_error(s, "namelen does not match dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp); 265 goto bail; 266 } 267 ok: 268 if (hpfs_sb(s)->sb_chk >= 2) b |= 1 << de->down; 269 if (de->down) if (de_down_pointer(de) < 0x10) { 270 hpfs_error(s, "bad down pointer in dnode %08x, dirent %03x, last %03x", secno, p, pp); 271 goto bail; 272 } 273 pp = p; 274 275 } 276 if (p != le32_to_cpu(dnode->first_free)) { 277 hpfs_error(s, "size on last dirent does not match first_free; dnode %08x", secno); 278 goto bail; 279 } 280 if (d[pp + 30] != 1 || d[pp + 31] != 255) { 281 hpfs_error(s, "dnode %08x does not end with \\377 entry", secno); 282 goto bail; 283 } 284 if (b == 3) printk("HPFS: warning: unbalanced dnode tree, dnode %08x; see hpfs.txt 4 more info\n", secno); 285 } 286 return dnode; 287 bail: 288 hpfs_brelse4(qbh); 289 return NULL; 290 } 291 292 dnode_secno hpfs_fnode_dno(struct super_block *s, ino_t ino) 293 { 294 struct buffer_head *bh; 295 struct fnode *fnode; 296 dnode_secno dno; 297 298 fnode = hpfs_map_fnode(s, ino, &bh); 299 if (!fnode) 300 return 0; 301 302 dno = le32_to_cpu(fnode->u.external[0].disk_secno); 303 brelse(bh); 304 return dno; 305 } 306