| /* |
| * linux/fs/hpfs/map.c |
| * |
| * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999 |
| * |
| * mapping structures to memory with some minimal checks |
| */ |
| |
| #include "hpfs_fn.h" |
| |
| __le32 *hpfs_map_dnode_bitmap(struct super_block *s, struct quad_buffer_head *qbh) |
| { |
| return hpfs_map_4sectors(s, hpfs_sb(s)->sb_dmap, qbh, 0); |
| } |
| |
| __le32 *hpfs_map_bitmap(struct super_block *s, unsigned bmp_block, |
| struct quad_buffer_head *qbh, char *id) |
| { |
| secno sec; |
| if (hpfs_sb(s)->sb_chk) if (bmp_block * 16384 > hpfs_sb(s)->sb_fs_size) { |
| hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id); |
| return NULL; |
| } |
| sec = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]); |
| if (!sec || sec > hpfs_sb(s)->sb_fs_size-4) { |
| hpfs_error(s, "invalid bitmap block pointer %08x -> %08x at %s", bmp_block, sec, id); |
| return NULL; |
| } |
| return hpfs_map_4sectors(s, sec, qbh, 4); |
| } |
| |
| /* |
| * Load first code page into kernel memory, return pointer to 256-byte array, |
| * first 128 bytes are uppercasing table for chars 128-255, next 128 bytes are |
| * lowercasing table |
| */ |
| |
| unsigned char *hpfs_load_code_page(struct super_block *s, secno cps) |
| { |
| struct buffer_head *bh; |
| secno cpds; |
| unsigned cpi; |
| unsigned char *ptr; |
| unsigned char *cp_table; |
| int i; |
| struct code_page_data *cpd; |
| struct code_page_directory *cp = hpfs_map_sector(s, cps, &bh, 0); |
| if (!cp) return NULL; |
| if (le32_to_cpu(cp->magic) != CP_DIR_MAGIC) { |
| printk("HPFS: Code page directory magic doesn't match (magic = %08x)\n", le32_to_cpu(cp->magic)); |
| brelse(bh); |
| return NULL; |
| } |
| if (!le32_to_cpu(cp->n_code_pages)) { |
| printk("HPFS: n_code_pages == 0\n"); |
| brelse(bh); |
| return NULL; |
| } |
| cpds = le32_to_cpu(cp->array[0].code_page_data); |
| cpi = le16_to_cpu(cp->array[0].index); |
| brelse(bh); |
| |
| if (cpi >= 3) { |
| printk("HPFS: Code page index out of array\n"); |
| return NULL; |
| } |
| |
| if (!(cpd = hpfs_map_sector(s, cpds, &bh, 0))) return NULL; |
| if (le16_to_cpu(cpd->offs[cpi]) > 0x178) { |
| printk("HPFS: Code page index out of sector\n"); |
| brelse(bh); |
| return NULL; |
| } |
| ptr = (unsigned char *)cpd + le16_to_cpu(cpd->offs[cpi]) + 6; |
| if (!(cp_table = kmalloc(256, GFP_KERNEL))) { |
| printk("HPFS: out of memory for code page table\n"); |
| brelse(bh); |
| return NULL; |
| } |
| memcpy(cp_table, ptr, 128); |
| brelse(bh); |
| |
| /* Try to build lowercasing table from uppercasing one */ |
| |
| for (i=128; i<256; i++) cp_table[i]=i; |
| for (i=128; i<256; i++) if (cp_table[i-128]!=i && cp_table[i-128]>=128) |
| cp_table[cp_table[i-128]] = i; |
| |
| return cp_table; |
| } |
| |
| secno *hpfs_load_bitmap_directory(struct super_block *s, secno bmp) |
| { |
| struct buffer_head *bh; |
| int n = (hpfs_sb(s)->sb_fs_size + 0x200000 - 1) >> 21; |
| int i; |
| secno *b; |
| if (!(b = kmalloc(n * 512, GFP_KERNEL))) { |
| printk("HPFS: can't allocate memory for bitmap directory\n"); |
| return NULL; |
| } |
| for (i=0;i<n;i++) { |
| secno *d = hpfs_map_sector(s, bmp+i, &bh, n - i - 1); |
| if (!d) { |
| kfree(b); |
| return NULL; |
| } |
| memcpy((char *)b + 512 * i, d, 512); |
| brelse(bh); |
| } |
| return b; |
| } |
| |
| /* |
| * Load fnode to memory |
| */ |
| |
| struct fnode *hpfs_map_fnode(struct super_block *s, ino_t ino, struct buffer_head **bhp) |
| { |
| struct fnode *fnode; |
| if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ino, 1, "fnode")) { |
| return NULL; |
| } |
| if ((fnode = hpfs_map_sector(s, ino, bhp, FNODE_RD_AHEAD))) { |
| if (hpfs_sb(s)->sb_chk) { |
| struct extended_attribute *ea; |
| struct extended_attribute *ea_end; |
| if (le32_to_cpu(fnode->magic) != FNODE_MAGIC) { |
| hpfs_error(s, "bad magic on fnode %08lx", |
| (unsigned long)ino); |
| goto bail; |
| } |
| if (!fnode_is_dir(fnode)) { |
| if ((unsigned)fnode->btree.n_used_nodes + (unsigned)fnode->btree.n_free_nodes != |
| (fnode->btree.internal ? 12 : 8)) { |
| hpfs_error(s, |
| "bad number of nodes in fnode %08lx", |
| (unsigned long)ino); |
| goto bail; |
| } |
| if (le16_to_cpu(fnode->btree.first_free) != |
| 8 + fnode->btree.n_used_nodes * (fnode->btree.internal ? 8 : 12)) { |
| hpfs_error(s, |
| "bad first_free pointer in fnode %08lx", |
| (unsigned long)ino); |
| goto bail; |
| } |
| } |
| if (le16_to_cpu(fnode->ea_size_s) && (le16_to_cpu(fnode->ea_offs) < 0xc4 || |
| le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s) + le16_to_cpu(fnode->ea_size_s) > 0x200)) { |
| hpfs_error(s, |
| "bad EA info in fnode %08lx: ea_offs == %04x ea_size_s == %04x", |
| (unsigned long)ino, |
| le16_to_cpu(fnode->ea_offs), le16_to_cpu(fnode->ea_size_s)); |
| goto bail; |
| } |
| ea = fnode_ea(fnode); |
| ea_end = fnode_end_ea(fnode); |
| while (ea != ea_end) { |
| if (ea > ea_end) { |
| hpfs_error(s, "bad EA in fnode %08lx", |
| (unsigned long)ino); |
| goto bail; |
| } |
| ea = next_ea(ea); |
| } |
| } |
| } |
| return fnode; |
| bail: |
| brelse(*bhp); |
| return NULL; |
| } |
| |
| struct anode *hpfs_map_anode(struct super_block *s, anode_secno ano, struct buffer_head **bhp) |
| { |
| struct anode *anode; |
| if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ano, 1, "anode")) return NULL; |
| if ((anode = hpfs_map_sector(s, ano, bhp, ANODE_RD_AHEAD))) |
| if (hpfs_sb(s)->sb_chk) { |
| if (le32_to_cpu(anode->magic) != ANODE_MAGIC) { |
| hpfs_error(s, "bad magic on anode %08x", ano); |
| goto bail; |
| } |
| if (le32_to_cpu(anode->self) != ano) { |
| hpfs_error(s, "self pointer invalid on anode %08x", ano); |
| goto bail; |
| } |
| if ((unsigned)anode->btree.n_used_nodes + (unsigned)anode->btree.n_free_nodes != |
| (anode->btree.internal ? 60 : 40)) { |
| hpfs_error(s, "bad number of nodes in anode %08x", ano); |
| goto bail; |
| } |
| if (le16_to_cpu(anode->btree.first_free) != |
| 8 + anode->btree.n_used_nodes * (anode->btree.internal ? 8 : 12)) { |
| hpfs_error(s, "bad first_free pointer in anode %08x", ano); |
| goto bail; |
| } |
| } |
| return anode; |
| bail: |
| brelse(*bhp); |
| return NULL; |
| } |
| |
| /* |
| * Load dnode to memory and do some checks |
| */ |
| |
| struct dnode *hpfs_map_dnode(struct super_block *s, unsigned secno, |
| struct quad_buffer_head *qbh) |
| { |
| struct dnode *dnode; |
| if (hpfs_sb(s)->sb_chk) { |
| if (hpfs_chk_sectors(s, secno, 4, "dnode")) return NULL; |
| if (secno & 3) { |
| hpfs_error(s, "dnode %08x not byte-aligned", secno); |
| return NULL; |
| } |
| } |
| if ((dnode = hpfs_map_4sectors(s, secno, qbh, DNODE_RD_AHEAD))) |
| if (hpfs_sb(s)->sb_chk) { |
| unsigned p, pp = 0; |
| unsigned char *d = (unsigned char *)dnode; |
| int b = 0; |
| if (le32_to_cpu(dnode->magic) != DNODE_MAGIC) { |
| hpfs_error(s, "bad magic on dnode %08x", secno); |
| goto bail; |
| } |
| if (le32_to_cpu(dnode->self) != secno) |
| hpfs_error(s, "bad self pointer on dnode %08x self = %08x", secno, le32_to_cpu(dnode->self)); |
| /* Check dirents - bad dirents would cause infinite |
| loops or shooting to memory */ |
| if (le32_to_cpu(dnode->first_free) > 2048) { |
| hpfs_error(s, "dnode %08x has first_free == %08x", secno, le32_to_cpu(dnode->first_free)); |
| goto bail; |
| } |
| for (p = 20; p < le32_to_cpu(dnode->first_free); p += d[p] + (d[p+1] << 8)) { |
| struct hpfs_dirent *de = (struct hpfs_dirent *)((char *)dnode + p); |
| 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) { |
| hpfs_error(s, "bad dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp); |
| goto bail; |
| } |
| if (((31 + de->namelen + de->down*4 + 3) & ~3) != le16_to_cpu(de->length)) { |
| if (((31 + de->namelen + de->down*4 + 3) & ~3) < le16_to_cpu(de->length) && s->s_flags & MS_RDONLY) goto ok; |
| hpfs_error(s, "namelen does not match dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp); |
| goto bail; |
| } |
| ok: |
| if (hpfs_sb(s)->sb_chk >= 2) b |= 1 << de->down; |
| if (de->down) if (de_down_pointer(de) < 0x10) { |
| hpfs_error(s, "bad down pointer in dnode %08x, dirent %03x, last %03x", secno, p, pp); |
| goto bail; |
| } |
| pp = p; |
| |
| } |
| if (p != le32_to_cpu(dnode->first_free)) { |
| hpfs_error(s, "size on last dirent does not match first_free; dnode %08x", secno); |
| goto bail; |
| } |
| if (d[pp + 30] != 1 || d[pp + 31] != 255) { |
| hpfs_error(s, "dnode %08x does not end with \\377 entry", secno); |
| goto bail; |
| } |
| if (b == 3) printk("HPFS: warning: unbalanced dnode tree, dnode %08x; see hpfs.txt 4 more info\n", secno); |
| } |
| return dnode; |
| bail: |
| hpfs_brelse4(qbh); |
| return NULL; |
| } |
| |
| dnode_secno hpfs_fnode_dno(struct super_block *s, ino_t ino) |
| { |
| struct buffer_head *bh; |
| struct fnode *fnode; |
| dnode_secno dno; |
| |
| fnode = hpfs_map_fnode(s, ino, &bh); |
| if (!fnode) |
| return 0; |
| |
| dno = le32_to_cpu(fnode->u.external[0].disk_secno); |
| brelse(bh); |
| return dno; |
| } |