[net-next-2.6.git] / fs / hpfs / map.c

/*
 *  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, hpfs_sb(s)->sb_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 (hpfs_sb(s)->sb_chk) if (bmp_block * 16384 > hpfs_sb(s)->sb_fs_size) {
		hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id);
		return NULL;
	}
	sec = 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;
	}
	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
 */

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 (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 (cpi >= 3) {
		printk("HPFS: Code page index out of array\n");
		return NULL;
	}
	
	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 = (unsigned 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 = (hpfs_sb(s)->sb_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 (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 (fnode->magic != FNODE_MAGIC) {
				hpfs_error(s, "bad magic on fnode %08lx",
					(unsigned long)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 %08lx",
					    (unsigned long)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 %08lx",
					    (unsigned long)ino);
					goto bail;
				}
			}
			if (fnode->ea_size_s && ((signed int)fnode->ea_offs < 0xc4 ||
			   (signed int)fnode->ea_offs + fnode->acl_size_s + fnode->ea_size_s > 0x200)) {
				hpfs_error(s,
					"bad EA info in fnode %08lx: ea_offs == %04x ea_size_s == %04x",
					(unsigned long)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 %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 (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 (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 (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) || p + 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) != de->length) {
					if (((31 + de->namelen + de->down*4 + 3) & ~3) < 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 != 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;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/hpfs/map.c
	3	*
	4	* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
	5	*
	6	* mapping structures to memory with some minimal checks
	7	*/
	8
	9	#include "hpfs_fn.h"
	10
	11	unsigned hpfs_map_dnode_bitmap(struct super_block s, struct quad_buffer_head *qbh)
	12	{
	13	return hpfs_map_4sectors(s, hpfs_sb(s)->sb_dmap, qbh, 0);
	14	}
	15
	16	unsigned int hpfs_map_bitmap(struct super_block s, unsigned bmp_block,
	17	struct quad_buffer_head qbh, char id)
	18	{
	19	secno sec;
	20	if (hpfs_sb(s)->sb_chk) if (bmp_block * 16384 > hpfs_sb(s)->sb_fs_size) {
	21	hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id);
	22	return NULL;
	23	}
	24	sec = hpfs_sb(s)->sb_bmp_dir[bmp_block];
	25	if (!sec \|\| sec > hpfs_sb(s)->sb_fs_size-4) {
	26	hpfs_error(s, "invalid bitmap block pointer %08x -> %08x at %s", bmp_block, sec, id);
	27	return NULL;
	28	}
	29	return hpfs_map_4sectors(s, sec, qbh, 4);
	30	}
	31
	32	/*
	33	* Load first code page into kernel memory, return pointer to 256-byte array,
	34	* first 128 bytes are uppercasing table for chars 128-255, next 128 bytes are
	35	* lowercasing table
	36	*/
	37
7e7742ee	38	unsigned char hpfs_load_code_page(struct super_block s, secno cps)
1da177e4 LT	39	{
	40	struct buffer_head *bh;
	41	secno cpds;
	42	unsigned cpi;
	43	unsigned char *ptr;
	44	unsigned char *cp_table;
	45	int i;
	46	struct code_page_data *cpd;
	47	struct code_page_directory *cp = hpfs_map_sector(s, cps, &bh, 0);
	48	if (!cp) return NULL;
	49	if (cp->magic != CP_DIR_MAGIC) {
	50	printk("HPFS: Code page directory magic doesn't match (magic = %08x)\n", cp->magic);
	51	brelse(bh);
	52	return NULL;
	53	}
	54	if (!cp->n_code_pages) {
	55	printk("HPFS: n_code_pages == 0\n");
	56	brelse(bh);
	57	return NULL;
	58	}
	59	cpds = cp->array[0].code_page_data;
	60	cpi = cp->array[0].index;
	61	brelse(bh);
	62
	63	if (cpi >= 3) {
	64	printk("HPFS: Code page index out of array\n");
	65	return NULL;
	66	}
	67
	68	if (!(cpd = hpfs_map_sector(s, cpds, &bh, 0))) return NULL;
	69	if ((unsigned)cpd->offs[cpi] > 0x178) {
	70	printk("HPFS: Code page index out of sector\n");
	71	brelse(bh);
	72	return NULL;
	73	}
7e7742ee	74	ptr = (unsigned char *)cpd + cpd->offs[cpi] + 6;
1da177e4 LT	75	if (!(cp_table = kmalloc(256, GFP_KERNEL))) {
	76	printk("HPFS: out of memory for code page table\n");
	77	brelse(bh);
	78	return NULL;
	79	}
	80	memcpy(cp_table, ptr, 128);
	81	brelse(bh);
	82
	83	/* Try to build lowercasing table from uppercasing one */
	84
	85	for (i=128; i<256; i++) cp_table[i]=i;
	86	for (i=128; i<256; i++) if (cp_table[i-128]!=i && cp_table[i-128]>=128)
	87	cp_table[cp_table[i-128]] = i;
	88
	89	return cp_table;
	90	}
	91
	92	secno hpfs_load_bitmap_directory(struct super_block s, secno bmp)
	93	{
	94	struct buffer_head *bh;
	95	int n = (hpfs_sb(s)->sb_fs_size + 0x200000 - 1) >> 21;
	96	int i;
	97	secno *b;
	98	if (!(b = kmalloc(n * 512, GFP_KERNEL))) {
	99	printk("HPFS: can't allocate memory for bitmap directory\n");
	100	return NULL;
	101	}
	102	for (i=0;i<n;i++) {
	103	secno *d = hpfs_map_sector(s, bmp+i, &bh, n - i - 1);
	104	if (!d) {
	105	kfree(b);
	106	return NULL;
	107	}
	108	memcpy((char )b + 512 i, d, 512);
	109	brelse(bh);
	110	}
	111	return b;
	112	}
	113
	114	/*
	115	* Load fnode to memory
	116	*/
	117
	118	struct fnode hpfs_map_fnode(struct super_block s, ino_t ino, struct buffer_head **bhp)
	119	{
	120	struct fnode *fnode;
	121	if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ino, 1, "fnode")) {
	122	return NULL;
	123	}
	124	if ((fnode = hpfs_map_sector(s, ino, bhp, FNODE_RD_AHEAD))) {
	125	if (hpfs_sb(s)->sb_chk) {
	126	struct extended_attribute *ea;
	127	struct extended_attribute *ea_end;
	128	if (fnode->magic != FNODE_MAGIC) {
18debbbc RD	129	hpfs_error(s, "bad magic on fnode %08lx",
18debbbc RD	130	(unsigned long)ino);
1da177e4 LT	131	goto bail;
	132	}
	133	if (!fnode->dirflag) {
	134	if ((unsigned)fnode->btree.n_used_nodes + (unsigned)fnode->btree.n_free_nodes !=
	135	(fnode->btree.internal ? 12 : 8)) {
18debbbc RD	136	hpfs_error(s,
	137	"bad number of nodes in fnode %08lx",
	138	(unsigned long)ino);
1da177e4 LT	139	goto bail;
	140	}
	141	if (fnode->btree.first_free !=
	142	8 + fnode->btree.n_used_nodes * (fnode->btree.internal ? 8 : 12)) {
18debbbc RD	143	hpfs_error(s,
	144	"bad first_free pointer in fnode %08lx",
	145	(unsigned long)ino);
1da177e4 LT	146	goto bail;
	147	}
	148	}
	149	if (fnode->ea_size_s && ((signed int)fnode->ea_offs < 0xc4 \|\|
	150	(signed int)fnode->ea_offs + fnode->acl_size_s + fnode->ea_size_s > 0x200)) {
18debbbc RD	151	hpfs_error(s,
	152	"bad EA info in fnode %08lx: ea_offs == %04x ea_size_s == %04x",
	153	(unsigned long)ino,
	154	fnode->ea_offs, fnode->ea_size_s);
1da177e4 LT	155	goto bail;
	156	}
	157	ea = fnode_ea(fnode);
	158	ea_end = fnode_end_ea(fnode);
	159	while (ea != ea_end) {
	160	if (ea > ea_end) {
18debbbc RD	161	hpfs_error(s, "bad EA in fnode %08lx",
18debbbc RD	162	(unsigned long)ino);
1da177e4 LT	163	goto bail;
	164	}
	165	ea = next_ea(ea);
	166	}
	167	}
	168	}
	169	return fnode;
	170	bail:
	171	brelse(*bhp);
	172	return NULL;
	173	}
	174
	175	struct anode hpfs_map_anode(struct super_block s, anode_secno ano, struct buffer_head **bhp)
	176	{
	177	struct anode *anode;
	178	if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ano, 1, "anode")) return NULL;
	179	if ((anode = hpfs_map_sector(s, ano, bhp, ANODE_RD_AHEAD)))
	180	if (hpfs_sb(s)->sb_chk) {
	181	if (anode->magic != ANODE_MAGIC \|\| anode->self != ano) {
	182	hpfs_error(s, "bad magic on anode %08x", ano);
	183	goto bail;
	184	}
	185	if ((unsigned)anode->btree.n_used_nodes + (unsigned)anode->btree.n_free_nodes !=
	186	(anode->btree.internal ? 60 : 40)) {
	187	hpfs_error(s, "bad number of nodes in anode %08x", ano);
	188	goto bail;
	189	}
	190	if (anode->btree.first_free !=
	191	8 + anode->btree.n_used_nodes * (anode->btree.internal ? 8 : 12)) {
	192	hpfs_error(s, "bad first_free pointer in anode %08x", ano);
	193	goto bail;
	194	}
	195	}
	196	return anode;
	197	bail:
	198	brelse(*bhp);
	199	return NULL;
	200	}
	201
	202	/*
	203	* Load dnode to memory and do some checks
	204	*/
	205
	206	struct dnode hpfs_map_dnode(struct super_block s, unsigned secno,
	207	struct quad_buffer_head *qbh)
	208	{
	209	struct dnode *dnode;
	210	if (hpfs_sb(s)->sb_chk) {
	211	if (hpfs_chk_sectors(s, secno, 4, "dnode")) return NULL;
	212	if (secno & 3) {
	213	hpfs_error(s, "dnode %08x not byte-aligned", secno);
	214	return NULL;
	215	}
	216	}
	217	if ((dnode = hpfs_map_4sectors(s, secno, qbh, DNODE_RD_AHEAD)))
	218	if (hpfs_sb(s)->sb_chk) {
	219	unsigned p, pp = 0;
7e7742ee	220	unsigned char d = (unsigned char )dnode;
1da177e4 LT	221	int b = 0;
	222	if (dnode->magic != DNODE_MAGIC) {
	223	hpfs_error(s, "bad magic on dnode %08x", secno);
	224	goto bail;
	225	}
	226	if (dnode->self != secno)
	227	hpfs_error(s, "bad self pointer on dnode %08x self = %08x", secno, dnode->self);
	228	/* Check dirents - bad dirents would cause infinite
	229	loops or shooting to memory */
	230	if (dnode->first_free > 2048/* \|\| dnode->first_free < 84*/) {
	231	hpfs_error(s, "dnode %08x has first_free == %08x", secno, dnode->first_free);
	232	goto bail;
	233	}
	234	for (p = 20; p < dnode->first_free; p += d[p] + (d[p+1] << 8)) {
	235	struct hpfs_dirent de = (struct hpfs_dirent )((char *)dnode + p);
	236	if (de->length > 292 \|\| (de->length < 32) \|\| (de->length & 3) \|\| p + de->length > 2048) {
	237	hpfs_error(s, "bad dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp);
	238	goto bail;
	239	}
	240	if (((31 + de->namelen + de->down*4 + 3) & ~3) != de->length) {
	241	if (((31 + de->namelen + de->down*4 + 3) & ~3) < de->length && s->s_flags & MS_RDONLY) goto ok;
	242	hpfs_error(s, "namelen does not match dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp);
	243	goto bail;
	244	}
	245	ok:
	246	if (hpfs_sb(s)->sb_chk >= 2) b \|= 1 << de->down;
	247	if (de->down) if (de_down_pointer(de) < 0x10) {
	248	hpfs_error(s, "bad down pointer in dnode %08x, dirent %03x, last %03x", secno, p, pp);
	249	goto bail;
	250	}
	251	pp = p;
	252
	253	}
	254	if (p != dnode->first_free) {
	255	hpfs_error(s, "size on last dirent does not match first_free; dnode %08x", secno);
	256	goto bail;
	257	}
	258	if (d[pp + 30] != 1 \|\| d[pp + 31] != 255) {
	259	hpfs_error(s, "dnode %08x does not end with \\377 entry", secno);
	260	goto bail;
	261	}
	262	if (b == 3) printk("HPFS: warning: unbalanced dnode tree, dnode %08x; see hpfs.txt 4 more info\n", secno);
	263	}
	264	return dnode;
	265	bail:
	266	hpfs_brelse4(qbh);
	267	return NULL;
	268	}
	269
	270	dnode_secno hpfs_fnode_dno(struct super_block *s, ino_t ino)
	271	{
	272	struct buffer_head *bh;
	273	struct fnode *fnode;
	274	dnode_secno dno;
	275
	276	fnode = hpfs_map_fnode(s, ino, &bh);
	277	if (!fnode)
	278	return 0;
	279
	280	dno = fnode->u.external[0].disk_secno;
	281	brelse(bh);
	282	return dno;
	283	}