diff options
Diffstat (limited to 'fs/hpfs/map.c')
| -rw-r--r-- | fs/hpfs/map.c | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/fs/hpfs/map.c b/fs/hpfs/map.c new file mode 100644 index 0000000..0fecdac --- /dev/null +++ b/fs/hpfs/map.c @@ -0,0 +1,275 @@ +/* + * 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" + +unsigned *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); +} + +unsigned int *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 = 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 + */ + +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 (cp->magic != CP_DIR_MAGIC) { + printk("HPFS: Code page directory magic doesn't match (magic = %08x)\n", cp->magic); + brelse(bh); + return NULL; + } + if (!cp->n_code_pages) { + printk("HPFS: n_code_pages == 0\n"); + brelse(bh); + return NULL; + } + cpds = cp->array[0].code_page_data; + cpi = 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 ((unsigned)cpd->offs[cpi] > 0x178) { + printk("HPFS: Code page index out of sector\n"); + brelse(bh); + return NULL; + } + ptr = (char *)cpd + 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 (fnode->magic != FNODE_MAGIC) { + hpfs_error(s, "bad magic on fnode %08x", ino); + goto bail; + } + if (!fnode->dirflag) { + 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 %08x", ino); + goto bail; + } + if (fnode->btree.first_free != + 8 + fnode->btree.n_used_nodes * (fnode->btree.internal ? 8 : 12)) { + hpfs_error(s, "bad first_free pointer in fnode %08x", ino); + goto bail; + } + } + if (fnode->ea_size_s && ((signed int)fnode->ea_offs < 0xc4 || + (signed int)fnode->ea_offs + fnode->acl_size_s + fnode->ea_size_s > 0x200)) { + hpfs_error(s, "bad EA info in fnode %08x: ea_offs == %04x ea_size_s == %04x", + ino, fnode->ea_offs, 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 %08x", 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 (anode->magic != ANODE_MAGIC || anode->self != ano) { + hpfs_error(s, "bad magic 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 (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 = (char *)dnode; + int b = 0; + if (dnode->magic != DNODE_MAGIC) { + hpfs_error(s, "bad magic on dnode %08x", secno); + goto bail; + } + if (dnode->self != secno) + hpfs_error(s, "bad self pointer on dnode %08x self = %08x", secno, dnode->self); + /* Check dirents - bad dirents would cause infinite + loops or shooting to memory */ + if (dnode->first_free > 2048/* || dnode->first_free < 84*/) { + hpfs_error(s, "dnode %08x has first_free == %08x", secno, dnode->first_free); + goto bail; + } + for (p = 20; p < dnode->first_free; p += d[p] + (d[p+1] << 8)) { + struct hpfs_dirent *de = (struct hpfs_dirent *)((char *)dnode + p); + if (de->length > 292 || (de->length < 32) || (de->length & 3) || p + 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) != de->length) { + if (((31 + de->namelen + de->down*4 + 3) & ~3) < 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 != 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 = fnode->u.external[0].disk_secno; + brelse(bh); + return dno; +} |
