[linux-block.git] / fs / hpfs / map.c

// 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(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 & 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;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* linux/fs/hpfs/map.c
	4	*
	5	* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
	6	*
	7	* mapping structures to memory with some minimal checks
	8	*/
	9
	10	#include "hpfs_fn.h"
	11
52576da3	12	__le32 hpfs_map_dnode_bitmap(struct super_block s, struct quad_buffer_head *qbh)
1da177e4 LT	13	{
	14	return hpfs_map_4sectors(s, hpfs_sb(s)->sb_dmap, qbh, 0);
	15	}
	16
52576da3	17	__le32 hpfs_map_bitmap(struct super_block s, unsigned bmp_block,
1da177e4 LT	18	struct quad_buffer_head qbh, char id)
	19	{
	20	secno sec;
275f495d	21	__le32 *ret;
3ebacb05 MP	22	unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;
3ebacb05 MP	23	if (hpfs_sb(s)->sb_chk) if (bmp_block >= n_bands) {
1da177e4 LT	24	hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id);
	25	return NULL;
	26	}
0b69760b	27	sec = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]);
1da177e4 LT	28	if (!sec \|\| sec > hpfs_sb(s)->sb_fs_size-4) {
	29	hpfs_error(s, "invalid bitmap block pointer %08x -> %08x at %s", bmp_block, sec, id);
	30	return NULL;
	31	}
275f495d MP	32	ret = hpfs_map_4sectors(s, sec, qbh, 4);
	33	if (ret) hpfs_prefetch_bitmap(s, bmp_block + 1);
	34	return ret;
	35	}
	36
	37	void hpfs_prefetch_bitmap(struct super_block *s, unsigned bmp_block)
	38	{
	39	unsigned to_prefetch, next_prefetch;
	40	unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;
	41	if (unlikely(bmp_block >= n_bands))
	42	return;
	43	to_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]);
	44	if (unlikely(bmp_block + 1 >= n_bands))
	45	next_prefetch = 0;
	46	else
	47	next_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block + 1]);
	48	hpfs_prefetch_sectors(s, to_prefetch, 4 + 4 * (to_prefetch + 4 == next_prefetch));
1da177e4 LT	49	}
	50
	51	/*
	52	* Load first code page into kernel memory, return pointer to 256-byte array,
	53	* first 128 bytes are uppercasing table for chars 128-255, next 128 bytes are
	54	* lowercasing table
	55	*/
	56
7e7742ee	57	unsigned char hpfs_load_code_page(struct super_block s, secno cps)
1da177e4 LT	58	{
	59	struct buffer_head *bh;
	60	secno cpds;
	61	unsigned cpi;
	62	unsigned char *ptr;
	63	unsigned char *cp_table;
	64	int i;
	65	struct code_page_data *cpd;
	66	struct code_page_directory *cp = hpfs_map_sector(s, cps, &bh, 0);
	67	if (!cp) return NULL;
0b69760b	68	if (le32_to_cpu(cp->magic) != CP_DIR_MAGIC) {
a19189e5	69	pr_err("Code page directory magic doesn't match (magic = %08x)\n",
b7cb1ce2	70	le32_to_cpu(cp->magic));
1da177e4 LT	71	brelse(bh);
	72	return NULL;
	73	}
0b69760b	74	if (!le32_to_cpu(cp->n_code_pages)) {
a19189e5	75	pr_err("n_code_pages == 0\n");
1da177e4 LT	76	brelse(bh);
	77	return NULL;
	78	}
0b69760b MP	79	cpds = le32_to_cpu(cp->array[0].code_page_data);
0b69760b MP	80	cpi = le16_to_cpu(cp->array[0].index);
1da177e4 LT	81	brelse(bh);
	82
	83	if (cpi >= 3) {
a19189e5	84	pr_err("Code page index out of array\n");
1da177e4 LT	85	return NULL;
	86	}
	87
	88	if (!(cpd = hpfs_map_sector(s, cpds, &bh, 0))) return NULL;
0b69760b	89	if (le16_to_cpu(cpd->offs[cpi]) > 0x178) {
a19189e5	90	pr_err("Code page index out of sector\n");
1da177e4 LT	91	brelse(bh);
	92	return NULL;
	93	}
0b69760b	94	ptr = (unsigned char *)cpd + le16_to_cpu(cpd->offs[cpi]) + 6;
1da177e4	95	if (!(cp_table = kmalloc(256, GFP_KERNEL))) {
a19189e5	96	pr_err("out of memory for code page table\n");
1da177e4 LT	97	brelse(bh);
	98	return NULL;
	99	}
	100	memcpy(cp_table, ptr, 128);
	101	brelse(bh);
	102
	103	/* Try to build lowercasing table from uppercasing one */
	104
	105	for (i=128; i<256; i++) cp_table[i]=i;
	106	for (i=128; i<256; i++) if (cp_table[i-128]!=i && cp_table[i-128]>=128)
	107	cp_table[cp_table[i-128]] = i;
	108
	109	return cp_table;
	110	}
	111
28fe3c19	112	__le32 hpfs_load_bitmap_directory(struct super_block s, secno bmp)
1da177e4 LT	113	{
	114	struct buffer_head *bh;
	115	int n = (hpfs_sb(s)->sb_fs_size + 0x200000 - 1) >> 21;
	116	int i;
28fe3c19	117	__le32 *b;
1da177e4	118	if (!(b = kmalloc(n * 512, GFP_KERNEL))) {
a19189e5	119	pr_err("can't allocate memory for bitmap directory\n");
1da177e4 LT	120	return NULL;
	121	}
	122	for (i=0;i<n;i++) {
28fe3c19	123	__le32 *d = hpfs_map_sector(s, bmp+i, &bh, n - i - 1);
1da177e4 LT	124	if (!d) {
	125	kfree(b);
	126	return NULL;
	127	}
	128	memcpy((char )b + 512 i, d, 512);
	129	brelse(bh);
	130	}
	131	return b;
	132	}
	133
a64eefaa MP	134	void hpfs_load_hotfix_map(struct super_block s, struct hpfs_spare_block spareblock)
	135	{
	136	struct quad_buffer_head qbh;
4e728cf8	137	__le32 *directory;
a64eefaa MP	138	u32 n_hotfixes, n_used_hotfixes;
	139	unsigned i;
	140
	141	n_hotfixes = le32_to_cpu(spareblock->n_spares);
	142	n_used_hotfixes = le32_to_cpu(spareblock->n_spares_used);
	143
	144	if (n_hotfixes > 256 \|\| n_used_hotfixes > n_hotfixes) {
	145	hpfs_error(s, "invalid number of hotfixes: %u, used: %u", n_hotfixes, n_used_hotfixes);
	146	return;
	147	}
	148	if (!(directory = hpfs_map_4sectors(s, le32_to_cpu(spareblock->hotfix_map), &qbh, 0))) {
	149	hpfs_error(s, "can't load hotfix map");
	150	return;
	151	}
	152	for (i = 0; i < n_used_hotfixes; i++) {
	153	hpfs_sb(s)->hotfix_from[i] = le32_to_cpu(directory[i]);
	154	hpfs_sb(s)->hotfix_to[i] = le32_to_cpu(directory[n_hotfixes + i]);
	155	}
	156	hpfs_sb(s)->n_hotfixes = n_used_hotfixes;
	157	hpfs_brelse4(&qbh);
	158	}
	159
1da177e4 LT	160	/*
	161	* Load fnode to memory
	162	*/
	163
	164	struct fnode hpfs_map_fnode(struct super_block s, ino_t ino, struct buffer_head **bhp)
	165	{
	166	struct fnode *fnode;
	167	if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ino, 1, "fnode")) {
	168	return NULL;
	169	}
	170	if ((fnode = hpfs_map_sector(s, ino, bhp, FNODE_RD_AHEAD))) {
	171	if (hpfs_sb(s)->sb_chk) {
	172	struct extended_attribute *ea;
	173	struct extended_attribute *ea_end;
0b69760b	174	if (le32_to_cpu(fnode->magic) != FNODE_MAGIC) {
18debbbc RD	175	hpfs_error(s, "bad magic on fnode %08lx",
18debbbc RD	176	(unsigned long)ino);
1da177e4 LT	177	goto bail;
1da177e4 LT	178	}
c4c99543	179	if (!fnode_is_dir(fnode)) {
1da177e4	180	if ((unsigned)fnode->btree.n_used_nodes + (unsigned)fnode->btree.n_free_nodes !=
ddc19e6e	181	(bp_internal(&fnode->btree) ? 12 : 8)) {
18debbbc RD	182	hpfs_error(s,
	183	"bad number of nodes in fnode %08lx",
	184	(unsigned long)ino);
1da177e4 LT	185	goto bail;
1da177e4 LT	186	}
0b69760b	187	if (le16_to_cpu(fnode->btree.first_free) !=
ddc19e6e	188	8 + fnode->btree.n_used_nodes * (bp_internal(&fnode->btree) ? 8 : 12)) {
18debbbc RD	189	hpfs_error(s,
	190	"bad first_free pointer in fnode %08lx",
	191	(unsigned long)ino);
1da177e4 LT	192	goto bail;
	193	}
	194	}
0b69760b MP	195	if (le16_to_cpu(fnode->ea_size_s) && (le16_to_cpu(fnode->ea_offs) < 0xc4 \|\|
0b69760b MP	196	le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s) + le16_to_cpu(fnode->ea_size_s) > 0x200)) {
18debbbc RD	197	hpfs_error(s,
	198	"bad EA info in fnode %08lx: ea_offs == %04x ea_size_s == %04x",
	199	(unsigned long)ino,
0b69760b	200	le16_to_cpu(fnode->ea_offs), le16_to_cpu(fnode->ea_size_s));
1da177e4 LT	201	goto bail;
	202	}
	203	ea = fnode_ea(fnode);
	204	ea_end = fnode_end_ea(fnode);
	205	while (ea != ea_end) {
	206	if (ea > ea_end) {
18debbbc RD	207	hpfs_error(s, "bad EA in fnode %08lx",
18debbbc RD	208	(unsigned long)ino);
1da177e4 LT	209	goto bail;
	210	}
	211	ea = next_ea(ea);
	212	}
	213	}
	214	}
	215	return fnode;
	216	bail:
	217	brelse(*bhp);
	218	return NULL;
	219	}
	220
	221	struct anode hpfs_map_anode(struct super_block s, anode_secno ano, struct buffer_head **bhp)
	222	{
	223	struct anode *anode;
	224	if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ano, 1, "anode")) return NULL;
	225	if ((anode = hpfs_map_sector(s, ano, bhp, ANODE_RD_AHEAD)))
	226	if (hpfs_sb(s)->sb_chk) {
0b69760b	227	if (le32_to_cpu(anode->magic) != ANODE_MAGIC) {
1da177e4 LT	228	hpfs_error(s, "bad magic on anode %08x", ano);
	229	goto bail;
	230	}
0b69760b MP	231	if (le32_to_cpu(anode->self) != ano) {
	232	hpfs_error(s, "self pointer invalid on anode %08x", ano);
	233	goto bail;
	234	}
1da177e4	235	if ((unsigned)anode->btree.n_used_nodes + (unsigned)anode->btree.n_free_nodes !=
ddc19e6e	236	(bp_internal(&anode->btree) ? 60 : 40)) {
1da177e4 LT	237	hpfs_error(s, "bad number of nodes in anode %08x", ano);
	238	goto bail;
	239	}
0b69760b	240	if (le16_to_cpu(anode->btree.first_free) !=
ddc19e6e	241	8 + anode->btree.n_used_nodes * (bp_internal(&anode->btree) ? 8 : 12)) {
1da177e4 LT	242	hpfs_error(s, "bad first_free pointer in anode %08x", ano);
	243	goto bail;
	244	}
	245	}
	246	return anode;
	247	bail:
	248	brelse(*bhp);
	249	return NULL;
	250	}
	251
	252	/*
	253	* Load dnode to memory and do some checks
	254	*/
	255
	256	struct dnode hpfs_map_dnode(struct super_block s, unsigned secno,
	257	struct quad_buffer_head *qbh)
	258	{
	259	struct dnode *dnode;
	260	if (hpfs_sb(s)->sb_chk) {
	261	if (hpfs_chk_sectors(s, secno, 4, "dnode")) return NULL;
	262	if (secno & 3) {
	263	hpfs_error(s, "dnode %08x not byte-aligned", secno);
	264	return NULL;
	265	}
	266	}
	267	if ((dnode = hpfs_map_4sectors(s, secno, qbh, DNODE_RD_AHEAD)))
	268	if (hpfs_sb(s)->sb_chk) {
	269	unsigned p, pp = 0;
7e7742ee	270	unsigned char d = (unsigned char )dnode;
1da177e4	271	int b = 0;
0b69760b	272	if (le32_to_cpu(dnode->magic) != DNODE_MAGIC) {
1da177e4 LT	273	hpfs_error(s, "bad magic on dnode %08x", secno);
	274	goto bail;
	275	}
0b69760b MP	276	if (le32_to_cpu(dnode->self) != secno)
0b69760b MP	277	hpfs_error(s, "bad self pointer on dnode %08x self = %08x", secno, le32_to_cpu(dnode->self));
1da177e4 LT	278	/* Check dirents - bad dirents would cause infinite
1da177e4 LT	279	loops or shooting to memory */
0b69760b MP	280	if (le32_to_cpu(dnode->first_free) > 2048) {
0b69760b MP	281	hpfs_error(s, "dnode %08x has first_free == %08x", secno, le32_to_cpu(dnode->first_free));
1da177e4 LT	282	goto bail;
1da177e4 LT	283	}
0b69760b	284	for (p = 20; p < le32_to_cpu(dnode->first_free); p += d[p] + (d[p+1] << 8)) {
1da177e4	285	struct hpfs_dirent de = (struct hpfs_dirent )((char *)dnode + p);
0b69760b	286	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) {
1da177e4 LT	287	hpfs_error(s, "bad dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp);
	288	goto bail;
	289	}
0b69760b MP	290	if (((31 + de->namelen + de->down*4 + 3) & ~3) != le16_to_cpu(de->length)) {
0b69760b MP	291	if (((31 + de->namelen + de->down*4 + 3) & ~3) < le16_to_cpu(de->length) && s->s_flags & MS_RDONLY) goto ok;
1da177e4 LT	292	hpfs_error(s, "namelen does not match dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp);
	293	goto bail;
	294	}
	295	ok:
	296	if (hpfs_sb(s)->sb_chk >= 2) b \|= 1 << de->down;
	297	if (de->down) if (de_down_pointer(de) < 0x10) {
	298	hpfs_error(s, "bad down pointer in dnode %08x, dirent %03x, last %03x", secno, p, pp);
	299	goto bail;
	300	}
	301	pp = p;
	302
	303	}
0b69760b	304	if (p != le32_to_cpu(dnode->first_free)) {
1da177e4 LT	305	hpfs_error(s, "size on last dirent does not match first_free; dnode %08x", secno);
	306	goto bail;
	307	}
	308	if (d[pp + 30] != 1 \|\| d[pp + 31] != 255) {
	309	hpfs_error(s, "dnode %08x does not end with \\377 entry", secno);
	310	goto bail;
	311	}
b7cb1ce2	312	if (b == 3)
a19189e5	313	pr_err("unbalanced dnode tree, dnode %08x; see hpfs.txt 4 more info\n",
b7cb1ce2	314	secno);
1da177e4 LT	315	}
	316	return dnode;
	317	bail:
	318	hpfs_brelse4(qbh);
	319	return NULL;
	320	}
	321
	322	dnode_secno hpfs_fnode_dno(struct super_block *s, ino_t ino)
	323	{
	324	struct buffer_head *bh;
	325	struct fnode *fnode;
	326	dnode_secno dno;
	327
	328	fnode = hpfs_map_fnode(s, ino, &bh);
	329	if (!fnode)
	330	return 0;
	331
0b69760b	332	dno = le32_to_cpu(fnode->u.external[0].disk_secno);
1da177e4 LT	333	brelse(bh);
	334	return dno;
	335	}