fs/hpfs/map.c

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