patch-2.3.2 linux/fs/hpfs/map.c

• Lines: 269
• Date: Thu May 13 23:48:20 1999
• Orig file: v2.3.1/linux/fs/hpfs/map.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.1/linux/fs/hpfs/map.c linux/fs/hpfs/map.c
@@ -0,0 +1,268 @@
+/*
+ *  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, s->s_hpfs_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 (s->s_hpfs_chk) if (bmp_block * 16384 > s->s_hpfs_fs_size) {
+		hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id);
+		return NULL;
+	}
+	sec = s->s_hpfs_bmp_dir[bmp_block];
+	if (!sec || sec > s->s_hpfs_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 (!(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 = (s->s_hpfs_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 (s->s_hpfs_chk) if (hpfs_chk_sectors(s, ino, 1, "fnode")) {
+		return NULL;
+	}
+	if ((fnode = hpfs_map_sector(s, ino, bhp, FNODE_RD_AHEAD))) {
+		if (s->s_hpfs_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->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 (s->s_hpfs_chk) if (hpfs_chk_sectors(s, ano, 1, "anode")) return NULL;
+	if ((anode = hpfs_map_sector(s, ano, bhp, ANODE_RD_AHEAD)))
+		if (s->s_hpfs_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 (s->s_hpfs_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 (s->s_hpfs_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)) {
+					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) {
+					hpfs_error(s, "namelen does not match dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp);
+					goto bail;
+				}
+				if (s->s_hpfs_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;
+}