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-rw-r--r--fs/hpfs/map.c335
1 files changed, 335 insertions, 0 deletions
diff --git a/fs/hpfs/map.c b/fs/hpfs/map.c
new file mode 100644
index 000000000..ecd9fccd1
--- /dev/null
+++ b/fs/hpfs/map.c
@@ -0,0 +1,335 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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_array(n, 512, GFP_KERNEL))) {
+ pr_err("can't allocate memory for bitmap directory\n");
+ return NULL;
+ }
+ for (i=0;i<n;i++) {
+ __le32 *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;
+}
+
+void hpfs_load_hotfix_map(struct super_block *s, struct hpfs_spare_block *spareblock)
+{
+ struct quad_buffer_head qbh;
+ __le32 *directory;
+ u32 n_hotfixes, n_used_hotfixes;
+ unsigned i;
+
+ n_hotfixes = le32_to_cpu(spareblock->n_spares);
+ n_used_hotfixes = le32_to_cpu(spareblock->n_spares_used);
+
+ if (n_hotfixes > 256 || n_used_hotfixes > n_hotfixes) {
+ hpfs_error(s, "invalid number of hotfixes: %u, used: %u", n_hotfixes, n_used_hotfixes);
+ return;
+ }
+ if (!(directory = hpfs_map_4sectors(s, le32_to_cpu(spareblock->hotfix_map), &qbh, 0))) {
+ hpfs_error(s, "can't load hotfix map");
+ return;
+ }
+ for (i = 0; i < n_used_hotfixes; i++) {
+ hpfs_sb(s)->hotfix_from[i] = le32_to_cpu(directory[i]);
+ hpfs_sb(s)->hotfix_to[i] = le32_to_cpu(directory[n_hotfixes + i]);
+ }
+ hpfs_sb(s)->n_hotfixes = n_used_hotfixes;
+ hpfs_brelse4(&qbh);
+}
+
+/*
+ * 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 !=
+ (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 & SB_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;
+}
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