284 lines
7.9 KiB
C
284 lines
7.9 KiB
C
/*
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* linux/fs/hpfs/map.c
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*
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* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
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*
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* mapping structures to memory with some minimal checks
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*/
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#include "hpfs_fn.h"
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unsigned *hpfs_map_dnode_bitmap(struct super_block *s, struct quad_buffer_head *qbh)
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{
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return hpfs_map_4sectors(s, hpfs_sb(s)->sb_dmap, qbh, 0);
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}
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unsigned int *hpfs_map_bitmap(struct super_block *s, unsigned bmp_block,
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struct quad_buffer_head *qbh, char *id)
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{
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secno sec;
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if (hpfs_sb(s)->sb_chk) if (bmp_block * 16384 > hpfs_sb(s)->sb_fs_size) {
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hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id);
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return NULL;
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}
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sec = hpfs_sb(s)->sb_bmp_dir[bmp_block];
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if (!sec || sec > hpfs_sb(s)->sb_fs_size-4) {
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hpfs_error(s, "invalid bitmap block pointer %08x -> %08x at %s", bmp_block, sec, id);
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return NULL;
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}
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return hpfs_map_4sectors(s, sec, qbh, 4);
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}
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/*
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* Load first code page into kernel memory, return pointer to 256-byte array,
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* first 128 bytes are uppercasing table for chars 128-255, next 128 bytes are
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* lowercasing table
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*/
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unsigned char *hpfs_load_code_page(struct super_block *s, secno cps)
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{
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struct buffer_head *bh;
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secno cpds;
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unsigned cpi;
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unsigned char *ptr;
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unsigned char *cp_table;
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int i;
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struct code_page_data *cpd;
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struct code_page_directory *cp = hpfs_map_sector(s, cps, &bh, 0);
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if (!cp) return NULL;
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if (cp->magic != CP_DIR_MAGIC) {
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printk("HPFS: Code page directory magic doesn't match (magic = %08x)\n", cp->magic);
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brelse(bh);
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return NULL;
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}
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if (!cp->n_code_pages) {
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printk("HPFS: n_code_pages == 0\n");
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brelse(bh);
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return NULL;
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}
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cpds = cp->array[0].code_page_data;
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cpi = cp->array[0].index;
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brelse(bh);
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if (cpi >= 3) {
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printk("HPFS: Code page index out of array\n");
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return NULL;
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}
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if (!(cpd = hpfs_map_sector(s, cpds, &bh, 0))) return NULL;
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if ((unsigned)cpd->offs[cpi] > 0x178) {
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printk("HPFS: Code page index out of sector\n");
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brelse(bh);
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return NULL;
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}
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ptr = (unsigned char *)cpd + cpd->offs[cpi] + 6;
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if (!(cp_table = kmalloc(256, GFP_KERNEL))) {
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printk("HPFS: out of memory for code page table\n");
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brelse(bh);
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return NULL;
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}
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memcpy(cp_table, ptr, 128);
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brelse(bh);
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/* Try to build lowercasing table from uppercasing one */
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for (i=128; i<256; i++) cp_table[i]=i;
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for (i=128; i<256; i++) if (cp_table[i-128]!=i && cp_table[i-128]>=128)
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cp_table[cp_table[i-128]] = i;
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return cp_table;
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}
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secno *hpfs_load_bitmap_directory(struct super_block *s, secno bmp)
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{
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struct buffer_head *bh;
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int n = (hpfs_sb(s)->sb_fs_size + 0x200000 - 1) >> 21;
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int i;
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secno *b;
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if (!(b = kmalloc(n * 512, GFP_KERNEL))) {
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printk("HPFS: can't allocate memory for bitmap directory\n");
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return NULL;
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}
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for (i=0;i<n;i++) {
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secno *d = hpfs_map_sector(s, bmp+i, &bh, n - i - 1);
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if (!d) {
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kfree(b);
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return NULL;
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}
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memcpy((char *)b + 512 * i, d, 512);
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brelse(bh);
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}
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return b;
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}
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/*
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* Load fnode to memory
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*/
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struct fnode *hpfs_map_fnode(struct super_block *s, ino_t ino, struct buffer_head **bhp)
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{
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struct fnode *fnode;
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if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ino, 1, "fnode")) {
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return NULL;
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}
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if ((fnode = hpfs_map_sector(s, ino, bhp, FNODE_RD_AHEAD))) {
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if (hpfs_sb(s)->sb_chk) {
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struct extended_attribute *ea;
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struct extended_attribute *ea_end;
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if (fnode->magic != FNODE_MAGIC) {
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hpfs_error(s, "bad magic on fnode %08lx",
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(unsigned long)ino);
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goto bail;
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}
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if (!fnode->dirflag) {
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if ((unsigned)fnode->btree.n_used_nodes + (unsigned)fnode->btree.n_free_nodes !=
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(fnode->btree.internal ? 12 : 8)) {
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hpfs_error(s,
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"bad number of nodes in fnode %08lx",
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(unsigned long)ino);
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goto bail;
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}
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if (fnode->btree.first_free !=
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8 + fnode->btree.n_used_nodes * (fnode->btree.internal ? 8 : 12)) {
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hpfs_error(s,
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"bad first_free pointer in fnode %08lx",
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(unsigned long)ino);
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goto bail;
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}
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}
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if (fnode->ea_size_s && ((signed int)fnode->ea_offs < 0xc4 ||
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(signed int)fnode->ea_offs + fnode->acl_size_s + fnode->ea_size_s > 0x200)) {
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hpfs_error(s,
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"bad EA info in fnode %08lx: ea_offs == %04x ea_size_s == %04x",
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(unsigned long)ino,
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fnode->ea_offs, fnode->ea_size_s);
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goto bail;
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}
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ea = fnode_ea(fnode);
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ea_end = fnode_end_ea(fnode);
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while (ea != ea_end) {
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if (ea > ea_end) {
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hpfs_error(s, "bad EA in fnode %08lx",
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(unsigned long)ino);
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goto bail;
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}
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ea = next_ea(ea);
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}
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}
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}
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return fnode;
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bail:
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brelse(*bhp);
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return NULL;
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}
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struct anode *hpfs_map_anode(struct super_block *s, anode_secno ano, struct buffer_head **bhp)
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{
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struct anode *anode;
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if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ano, 1, "anode")) return NULL;
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if ((anode = hpfs_map_sector(s, ano, bhp, ANODE_RD_AHEAD)))
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if (hpfs_sb(s)->sb_chk) {
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if (anode->magic != ANODE_MAGIC || anode->self != ano) {
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hpfs_error(s, "bad magic on anode %08x", ano);
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goto bail;
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}
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if ((unsigned)anode->btree.n_used_nodes + (unsigned)anode->btree.n_free_nodes !=
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(anode->btree.internal ? 60 : 40)) {
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hpfs_error(s, "bad number of nodes in anode %08x", ano);
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goto bail;
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}
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if (anode->btree.first_free !=
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8 + anode->btree.n_used_nodes * (anode->btree.internal ? 8 : 12)) {
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hpfs_error(s, "bad first_free pointer in anode %08x", ano);
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goto bail;
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}
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}
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return anode;
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bail:
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brelse(*bhp);
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return NULL;
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}
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/*
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* Load dnode to memory and do some checks
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*/
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struct dnode *hpfs_map_dnode(struct super_block *s, unsigned secno,
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struct quad_buffer_head *qbh)
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{
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struct dnode *dnode;
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if (hpfs_sb(s)->sb_chk) {
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if (hpfs_chk_sectors(s, secno, 4, "dnode")) return NULL;
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if (secno & 3) {
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hpfs_error(s, "dnode %08x not byte-aligned", secno);
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return NULL;
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}
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}
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if ((dnode = hpfs_map_4sectors(s, secno, qbh, DNODE_RD_AHEAD)))
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if (hpfs_sb(s)->sb_chk) {
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unsigned p, pp = 0;
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unsigned char *d = (unsigned char *)dnode;
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int b = 0;
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if (dnode->magic != DNODE_MAGIC) {
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hpfs_error(s, "bad magic on dnode %08x", secno);
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goto bail;
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}
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if (dnode->self != secno)
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hpfs_error(s, "bad self pointer on dnode %08x self = %08x", secno, dnode->self);
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/* Check dirents - bad dirents would cause infinite
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loops or shooting to memory */
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if (dnode->first_free > 2048/* || dnode->first_free < 84*/) {
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hpfs_error(s, "dnode %08x has first_free == %08x", secno, dnode->first_free);
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goto bail;
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}
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for (p = 20; p < dnode->first_free; p += d[p] + (d[p+1] << 8)) {
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struct hpfs_dirent *de = (struct hpfs_dirent *)((char *)dnode + p);
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if (de->length > 292 || (de->length < 32) || (de->length & 3) || p + de->length > 2048) {
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hpfs_error(s, "bad dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp);
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goto bail;
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}
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if (((31 + de->namelen + de->down*4 + 3) & ~3) != de->length) {
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if (((31 + de->namelen + de->down*4 + 3) & ~3) < de->length && s->s_flags & MS_RDONLY) goto ok;
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hpfs_error(s, "namelen does not match dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp);
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goto bail;
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}
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ok:
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if (hpfs_sb(s)->sb_chk >= 2) b |= 1 << de->down;
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if (de->down) if (de_down_pointer(de) < 0x10) {
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hpfs_error(s, "bad down pointer in dnode %08x, dirent %03x, last %03x", secno, p, pp);
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goto bail;
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}
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pp = p;
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}
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if (p != dnode->first_free) {
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hpfs_error(s, "size on last dirent does not match first_free; dnode %08x", secno);
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goto bail;
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}
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if (d[pp + 30] != 1 || d[pp + 31] != 255) {
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hpfs_error(s, "dnode %08x does not end with \\377 entry", secno);
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goto bail;
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}
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if (b == 3) printk("HPFS: warning: unbalanced dnode tree, dnode %08x; see hpfs.txt 4 more info\n", secno);
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}
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return dnode;
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bail:
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hpfs_brelse4(qbh);
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return NULL;
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}
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dnode_secno hpfs_fnode_dno(struct super_block *s, ino_t ino)
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{
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struct buffer_head *bh;
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struct fnode *fnode;
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dnode_secno dno;
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fnode = hpfs_map_fnode(s, ino, &bh);
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if (!fnode)
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return 0;
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dno = fnode->u.external[0].disk_secno;
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brelse(bh);
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return dno;
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}
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