From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- fs/hpfs/map.c | 308 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 308 insertions(+) create mode 100644 fs/hpfs/map.c (limited to 'fs/hpfs/map.c') diff --git a/fs/hpfs/map.c b/fs/hpfs/map.c new file mode 100644 index 000000000..442770edc --- /dev/null +++ b/fs/hpfs/map.c @@ -0,0 +1,308 @@ +/* + * 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; + __le32 *ret; + unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14; + if (hpfs_sb(s)->sb_chk) if (bmp_block >= n_bands) { + 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; + } + ret = hpfs_map_4sectors(s, sec, qbh, 4); + if (ret) hpfs_prefetch_bitmap(s, bmp_block + 1); + return ret; +} + +void hpfs_prefetch_bitmap(struct super_block *s, unsigned bmp_block) +{ + unsigned to_prefetch, next_prefetch; + unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14; + if (unlikely(bmp_block >= n_bands)) + return; + to_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]); + if (unlikely(bmp_block + 1 >= n_bands)) + next_prefetch = 0; + else + next_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block + 1]); + hpfs_prefetch_sectors(s, to_prefetch, 4 + 4 * (to_prefetch + 4 == next_prefetch)); +} + +/* + * 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) { + pr_err("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)) { + pr_err("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) { + pr_err("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) { + pr_err("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))) { + pr_err("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; +} + +__le32 *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; + __le32 *b; + if (!(b = kmalloc(n * 512, GFP_KERNEL))) { + pr_err("can't allocate memory for bitmap directory\n"); + return NULL; + } + for (i=0;isb_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 != + (bp_internal(&fnode->btree) ? 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 * (bp_internal(&fnode->btree) ? 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 != + (bp_internal(&anode->btree) ? 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 * (bp_internal(&anode->btree) ? 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) + pr_err("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; +} -- cgit v1.2.3-54-g00ecf