[linux-2.6-block.git] / fs / adfs / dir_f.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/fs/adfs/dir_f.c
 *
 * Copyright (C) 1997-1999 Russell King
 *
 *  E and F format directory handling
 */
#include "adfs.h"
#include "dir_f.h"

static void adfs_f_free(struct adfs_dir *dir);

/*
 * Read an (unaligned) value of length 1..4 bytes
 */
static inline unsigned int adfs_readval(unsigned char *p, int len)
{
	unsigned int val = 0;

	switch (len) {
	case 4:		val |= p[3] << 24;
			/* fall through */
	case 3:		val |= p[2] << 16;
			/* fall through */
	case 2:		val |= p[1] << 8;
			/* fall through */
	default:	val |= p[0];
	}
	return val;
}

static inline void adfs_writeval(unsigned char *p, int len, unsigned int val)
{
	switch (len) {
	case 4:		p[3] = val >> 24;
			/* fall through */
	case 3:		p[2] = val >> 16;
			/* fall through */
	case 2:		p[1] = val >> 8;
			/* fall through */
	default:	p[0] = val;
	}
}

#define ror13(v) ((v >> 13) | (v << 19))

#define dir_u8(idx)				\
	({ int _buf = idx >> blocksize_bits;	\
	   int _off = idx - (_buf << blocksize_bits);\
	  *(u8 *)(bh[_buf]->b_data + _off);	\
	})

#define dir_u32(idx)				\
	({ int _buf = idx >> blocksize_bits;	\
	   int _off = idx - (_buf << blocksize_bits);\
	  *(__le32 *)(bh[_buf]->b_data + _off);	\
	})

#define bufoff(_bh,_idx)			\
	({ int _buf = _idx >> blocksize_bits;	\
	   int _off = _idx - (_buf << blocksize_bits);\
	  (u8 *)(_bh[_buf]->b_data + _off);	\
	})

/*
 * There are some algorithms that are nice in
 * assembler, but a bitch in C...  This is one
 * of them.
 */
static u8
adfs_dir_checkbyte(const struct adfs_dir *dir)
{
	struct buffer_head * const *bh = dir->bh;
	const int blocksize_bits = dir->sb->s_blocksize_bits;
	union { __le32 *ptr32; u8 *ptr8; } ptr, end;
	u32 dircheck = 0;
	int last = 5 - 26;
	int i = 0;

	/*
	 * Accumulate each word up to the last whole
	 * word of the last directory entry.  This
	 * can spread across several buffer heads.
	 */
	do {
		last += 26;
		do {
			dircheck = le32_to_cpu(dir_u32(i)) ^ ror13(dircheck);

			i += sizeof(u32);
		} while (i < (last & ~3));
	} while (dir_u8(last) != 0);

	/*
	 * Accumulate the last few bytes.  These
	 * bytes will be within the same bh.
	 */
	if (i != last) {
		ptr.ptr8 = bufoff(bh, i);
		end.ptr8 = ptr.ptr8 + last - i;

		do {
			dircheck = *ptr.ptr8++ ^ ror13(dircheck);
		} while (ptr.ptr8 < end.ptr8);
	}

	/*
	 * The directory tail is in the final bh
	 * Note that contary to the RISC OS PRMs,
	 * the first few bytes are NOT included
	 * in the check.  All bytes are in the
	 * same bh.
	 */
	ptr.ptr8 = bufoff(bh, 2008);
	end.ptr8 = ptr.ptr8 + 36;

	do {
		__le32 v = *ptr.ptr32++;
		dircheck = le32_to_cpu(v) ^ ror13(dircheck);
	} while (ptr.ptr32 < end.ptr32);

	return (dircheck ^ (dircheck >> 8) ^ (dircheck >> 16) ^ (dircheck >> 24)) & 0xff;
}

/* Read and check that a directory is valid */
static int adfs_dir_read(struct super_block *sb, u32 indaddr,
			 unsigned int size, struct adfs_dir *dir)
{
	const unsigned int blocksize_bits = sb->s_blocksize_bits;
	int blk = 0;

	/*
	 * Directories which are not a multiple of 2048 bytes
	 * are considered bad v2 [3.6]
	 */
	if (size & 2047)
		goto bad_dir;

	size >>= blocksize_bits;

	dir->nr_buffers = 0;
	dir->sb = sb;

	for (blk = 0; blk < size; blk++) {
		int phys;

		phys = __adfs_block_map(sb, indaddr, blk);
		if (!phys) {
			adfs_error(sb, "dir %06x has a hole at offset %d",
				   indaddr, blk);
			goto release_buffers;
		}

		dir->bh[blk] = sb_bread(sb, phys);
		if (!dir->bh[blk])
			goto release_buffers;
	}

	memcpy(&dir->dirhead, bufoff(dir->bh, 0), sizeof(dir->dirhead));
	memcpy(&dir->dirtail, bufoff(dir->bh, 2007), sizeof(dir->dirtail));

	if (dir->dirhead.startmasseq != dir->dirtail.new.endmasseq ||
	    memcmp(&dir->dirhead.startname, &dir->dirtail.new.endname, 4))
		goto bad_dir;

	if (memcmp(&dir->dirhead.startname, "Nick", 4) &&
	    memcmp(&dir->dirhead.startname, "Hugo", 4))
		goto bad_dir;

	if (adfs_dir_checkbyte(dir) != dir->dirtail.new.dircheckbyte)
		goto bad_dir;

	dir->nr_buffers = blk;

	return 0;

bad_dir:
	adfs_error(sb, "dir %06x is corrupted", indaddr);
release_buffers:
	for (blk -= 1; blk >= 0; blk -= 1)
		brelse(dir->bh[blk]);

	dir->sb = NULL;

	return -EIO;
}

/*
 * convert a disk-based directory entry to a Linux ADFS directory entry
 */
static inline void
adfs_dir2obj(struct adfs_dir *dir, struct object_info *obj,
	struct adfs_direntry *de)
{
	unsigned int name_len;

	for (name_len = 0; name_len < ADFS_F_NAME_LEN; name_len++) {
		if (de->dirobname[name_len] < ' ')
			break;

		obj->name[name_len] = de->dirobname[name_len];
	}

	obj->name_len =	name_len;
	obj->indaddr  = adfs_readval(de->dirinddiscadd, 3);
	obj->loadaddr = adfs_readval(de->dirload, 4);
	obj->execaddr = adfs_readval(de->direxec, 4);
	obj->size     = adfs_readval(de->dirlen,  4);
	obj->attr     = de->newdiratts;

	adfs_object_fixup(dir, obj);
}

/*
 * convert a Linux ADFS directory entry to a disk-based directory entry
 */
static inline void
adfs_obj2dir(struct adfs_direntry *de, struct object_info *obj)
{
	adfs_writeval(de->dirinddiscadd, 3, obj->indaddr);
	adfs_writeval(de->dirload, 4, obj->loadaddr);
	adfs_writeval(de->direxec, 4, obj->execaddr);
	adfs_writeval(de->dirlen,  4, obj->size);
	de->newdiratts = obj->attr;
}

/*
 * get a directory entry.  Note that the caller is responsible
 * for holding the relevant locks.
 */
static int
__adfs_dir_get(struct adfs_dir *dir, int pos, struct object_info *obj)
{
	struct super_block *sb = dir->sb;
	struct adfs_direntry de;
	int thissize, buffer, offset;

	buffer = pos >> sb->s_blocksize_bits;

	if (buffer > dir->nr_buffers)
		return -EINVAL;

	offset = pos & (sb->s_blocksize - 1);
	thissize = sb->s_blocksize - offset;
	if (thissize > 26)
		thissize = 26;

	memcpy(&de, dir->bh[buffer]->b_data + offset, thissize);
	if (thissize != 26)
		memcpy(((char *)&de) + thissize, dir->bh[buffer + 1]->b_data,
		       26 - thissize);

	if (!de.dirobname[0])
		return -ENOENT;

	adfs_dir2obj(dir, obj, &de);

	return 0;
}

static int
__adfs_dir_put(struct adfs_dir *dir, int pos, struct object_info *obj)
{
	struct super_block *sb = dir->sb;
	struct adfs_direntry de;
	int thissize, buffer, offset;

	buffer = pos >> sb->s_blocksize_bits;

	if (buffer > dir->nr_buffers)
		return -EINVAL;

	offset = pos & (sb->s_blocksize - 1);
	thissize = sb->s_blocksize - offset;
	if (thissize > 26)
		thissize = 26;

	/*
	 * Get the entry in total
	 */
	memcpy(&de, dir->bh[buffer]->b_data + offset, thissize);
	if (thissize != 26)
		memcpy(((char *)&de) + thissize, dir->bh[buffer + 1]->b_data,
		       26 - thissize);

	/*
	 * update it
	 */
	adfs_obj2dir(&de, obj);

	/*
	 * Put the new entry back
	 */
	memcpy(dir->bh[buffer]->b_data + offset, &de, thissize);
	if (thissize != 26)
		memcpy(dir->bh[buffer + 1]->b_data, ((char *)&de) + thissize,
		       26 - thissize);

	return 0;
}

/*
 * the caller is responsible for holding the necessary
 * locks.
 */
static int adfs_dir_find_entry(struct adfs_dir *dir, u32 indaddr)
{
	int pos, ret;

	ret = -ENOENT;

	for (pos = 5; pos < ADFS_NUM_DIR_ENTRIES * 26 + 5; pos += 26) {
		struct object_info obj;

		if (!__adfs_dir_get(dir, pos, &obj))
			break;

		if (obj.indaddr == indaddr) {
			ret = pos;
			break;
		}
	}

	return ret;
}

static int adfs_f_read(struct super_block *sb, u32 indaddr, unsigned int size,
		       struct adfs_dir *dir)
{
	int ret;

	if (size != ADFS_NEWDIR_SIZE)
		return -EIO;

	ret = adfs_dir_read(sb, indaddr, size, dir);
	if (ret)
		adfs_error(sb, "unable to read directory");
	else
		dir->parent_id = adfs_readval(dir->dirtail.new.dirparent, 3);

	return ret;
}

static int
adfs_f_setpos(struct adfs_dir *dir, unsigned int fpos)
{
	if (fpos >= ADFS_NUM_DIR_ENTRIES)
		return -ENOENT;

	dir->pos = 5 + fpos * 26;
	return 0;
}

static int
adfs_f_getnext(struct adfs_dir *dir, struct object_info *obj)
{
	unsigned int ret;

	ret = __adfs_dir_get(dir, dir->pos, obj);
	if (ret == 0)
		dir->pos += 26;

	return ret;
}

static int
adfs_f_update(struct adfs_dir *dir, struct object_info *obj)
{
	struct super_block *sb = dir->sb;
	int ret, i;

	ret = adfs_dir_find_entry(dir, obj->indaddr);
	if (ret < 0) {
		adfs_error(dir->sb, "unable to locate entry to update");
		goto out;
	}

	__adfs_dir_put(dir, ret, obj);
 
	/*
	 * Increment directory sequence number
	 */
	dir->bh[0]->b_data[0] += 1;
	dir->bh[dir->nr_buffers - 1]->b_data[sb->s_blocksize - 6] += 1;

	ret = adfs_dir_checkbyte(dir);
	/*
	 * Update directory check byte
	 */
	dir->bh[dir->nr_buffers - 1]->b_data[sb->s_blocksize - 1] = ret;

#if 1
	{
	const unsigned int blocksize_bits = sb->s_blocksize_bits;

	memcpy(&dir->dirhead, bufoff(dir->bh, 0), sizeof(dir->dirhead));
	memcpy(&dir->dirtail, bufoff(dir->bh, 2007), sizeof(dir->dirtail));

	if (dir->dirhead.startmasseq != dir->dirtail.new.endmasseq ||
	    memcmp(&dir->dirhead.startname, &dir->dirtail.new.endname, 4))
		goto bad_dir;

	if (memcmp(&dir->dirhead.startname, "Nick", 4) &&
	    memcmp(&dir->dirhead.startname, "Hugo", 4))
		goto bad_dir;

	if (adfs_dir_checkbyte(dir) != dir->dirtail.new.dircheckbyte)
		goto bad_dir;
	}
#endif
	for (i = dir->nr_buffers - 1; i >= 0; i--)
		mark_buffer_dirty(dir->bh[i]);

	ret = 0;
out:
	return ret;
#if 1
bad_dir:
	adfs_error(dir->sb, "whoops!  I broke a directory!");
	return -EIO;
#endif
}

static int
adfs_f_sync(struct adfs_dir *dir)
{
	int err = 0;
	int i;

	for (i = dir->nr_buffers - 1; i >= 0; i--) {
		struct buffer_head *bh = dir->bh[i];
		sync_dirty_buffer(bh);
		if (buffer_req(bh) && !buffer_uptodate(bh))
			err = -EIO;
	}

	return err;
}

static void
adfs_f_free(struct adfs_dir *dir)
{
	int i;

	for (i = dir->nr_buffers - 1; i >= 0; i--) {
		brelse(dir->bh[i]);
		dir->bh[i] = NULL;
	}

	dir->nr_buffers = 0;
	dir->sb = NULL;
}

const struct adfs_dir_ops adfs_f_dir_ops = {
	.read		= adfs_f_read,
	.setpos		= adfs_f_setpos,
	.getnext	= adfs_f_getnext,
	.update		= adfs_f_update,
	.sync		= adfs_f_sync,
	.free		= adfs_f_free
};
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	/*
	3	* linux/fs/adfs/dir_f.c
	4	*
	5	* Copyright (C) 1997-1999 Russell King
	6	*
1da177e4 LT	7	* E and F format directory handling
1da177e4 LT	8	*/
1da177e4 LT	9	#include "adfs.h"
	10	#include "dir_f.h"
	11
	12	static void adfs_f_free(struct adfs_dir *dir);
	13
	14	/*
	15	* Read an (unaligned) value of length 1..4 bytes
	16	*/
	17	static inline unsigned int adfs_readval(unsigned char *p, int len)
	18	{
	19	unsigned int val = 0;
	20
	21	switch (len) {
	22	case 4: val \|= p[3] << 24;
74f79099	23	/* fall through */
1da177e4	24	case 3: val \|= p[2] << 16;
74f79099	25	/* fall through */
1da177e4	26	case 2: val \|= p[1] << 8;
74f79099	27	/* fall through */
1da177e4 LT	28	default: val \|= p[0];
	29	}
	30	return val;
	31	}
	32
	33	static inline void adfs_writeval(unsigned char *p, int len, unsigned int val)
	34	{
	35	switch (len) {
	36	case 4: p[3] = val >> 24;
74f79099	37	/* fall through */
1da177e4	38	case 3: p[2] = val >> 16;
74f79099	39	/* fall through */
1da177e4	40	case 2: p[1] = val >> 8;
74f79099	41	/* fall through */
1da177e4 LT	42	default: p[0] = val;
	43	}
	44	}
	45
1da177e4 LT	46	#define ror13(v) ((v >> 13) \| (v << 19))
	47
	48	#define dir_u8(idx) \
	49	({ int _buf = idx >> blocksize_bits; \
	50	int _off = idx - (_buf << blocksize_bits);\
	51	(u8 )(bh[_buf]->b_data + _off); \
	52	})
	53
	54	#define dir_u32(idx) \
	55	({ int _buf = idx >> blocksize_bits; \
	56	int _off = idx - (_buf << blocksize_bits);\
	57	(__le32 )(bh[_buf]->b_data + _off); \
	58	})
	59
	60	#define bufoff(_bh,_idx) \
	61	({ int _buf = _idx >> blocksize_bits; \
	62	int _off = _idx - (_buf << blocksize_bits);\
	63	(u8 *)(_bh[_buf]->b_data + _off); \
	64	})
	65
	66	/*
	67	* There are some algorithms that are nice in
	68	* assembler, but a bitch in C... This is one
	69	* of them.
	70	*/
	71	static u8
	72	adfs_dir_checkbyte(const struct adfs_dir *dir)
	73	{
	74	struct buffer_head * const *bh = dir->bh;
	75	const int blocksize_bits = dir->sb->s_blocksize_bits;
	76	union { __le32 ptr32; u8 ptr8; } ptr, end;
	77	u32 dircheck = 0;
	78	int last = 5 - 26;
	79	int i = 0;
	80
	81	/*
	82	* Accumulate each word up to the last whole
	83	* word of the last directory entry. This
	84	* can spread across several buffer heads.
	85	*/
	86	do {
	87	last += 26;
	88	do {
	89	dircheck = le32_to_cpu(dir_u32(i)) ^ ror13(dircheck);
	90
	91	i += sizeof(u32);
	92	} while (i < (last & ~3));
	93	} while (dir_u8(last) != 0);
	94
	95	/*
	96	* Accumulate the last few bytes. These
	97	* bytes will be within the same bh.
	98	*/
	99	if (i != last) {
	100	ptr.ptr8 = bufoff(bh, i);
	101	end.ptr8 = ptr.ptr8 + last - i;
	102
e5949050	103	do {
1da177e4	104	dircheck = *ptr.ptr8++ ^ ror13(dircheck);
e5949050	105	} while (ptr.ptr8 < end.ptr8);
1da177e4 LT	106	}
	107
	108	/*
	109	* The directory tail is in the final bh
	110	* Note that contary to the RISC OS PRMs,
	111	* the first few bytes are NOT included
	112	* in the check. All bytes are in the
	113	* same bh.
	114	*/
	115	ptr.ptr8 = bufoff(bh, 2008);
	116	end.ptr8 = ptr.ptr8 + 36;
	117
	118	do {
	119	__le32 v = *ptr.ptr32++;
	120	dircheck = le32_to_cpu(v) ^ ror13(dircheck);
	121	} while (ptr.ptr32 < end.ptr32);
	122
	123	return (dircheck ^ (dircheck >> 8) ^ (dircheck >> 16) ^ (dircheck >> 24)) & 0xff;
	124	}
	125
5ed70bb4 RK	126	/* Read and check that a directory is valid */
	127	static int adfs_dir_read(struct super_block *sb, u32 indaddr,
	128	unsigned int size, struct adfs_dir *dir)
1da177e4 LT	129	{
	130	const unsigned int blocksize_bits = sb->s_blocksize_bits;
	131	int blk = 0;
	132
	133	/*
	134	* Directories which are not a multiple of 2048 bytes
	135	* are considered bad v2 [3.6]
	136	*/
	137	if (size & 2047)
	138	goto bad_dir;
	139
	140	size >>= blocksize_bits;
	141
	142	dir->nr_buffers = 0;
	143	dir->sb = sb;
	144
	145	for (blk = 0; blk < size; blk++) {
	146	int phys;
	147
5ed70bb4	148	phys = __adfs_block_map(sb, indaddr, blk);
1da177e4	149	if (!phys) {
5ed70bb4 RK	150	adfs_error(sb, "dir %06x has a hole at offset %d",
5ed70bb4 RK	151	indaddr, blk);
1da177e4 LT	152	goto release_buffers;
	153	}
	154
	155	dir->bh[blk] = sb_bread(sb, phys);
	156	if (!dir->bh[blk])
	157	goto release_buffers;
	158	}
	159
	160	memcpy(&dir->dirhead, bufoff(dir->bh, 0), sizeof(dir->dirhead));
	161	memcpy(&dir->dirtail, bufoff(dir->bh, 2007), sizeof(dir->dirtail));
	162
	163	if (dir->dirhead.startmasseq != dir->dirtail.new.endmasseq \|\|
	164	memcmp(&dir->dirhead.startname, &dir->dirtail.new.endname, 4))
	165	goto bad_dir;
	166
	167	if (memcmp(&dir->dirhead.startname, "Nick", 4) &&
	168	memcmp(&dir->dirhead.startname, "Hugo", 4))
	169	goto bad_dir;
	170
	171	if (adfs_dir_checkbyte(dir) != dir->dirtail.new.dircheckbyte)
	172	goto bad_dir;
	173
	174	dir->nr_buffers = blk;
	175
	176	return 0;
	177
	178	bad_dir:
5ed70bb4	179	adfs_error(sb, "dir %06x is corrupted", indaddr);
1da177e4 LT	180	release_buffers:
	181	for (blk -= 1; blk >= 0; blk -= 1)
	182	brelse(dir->bh[blk]);
	183
	184	dir->sb = NULL;
	185
	186	return -EIO;
	187	}
	188
	189	/*
	190	* convert a disk-based directory entry to a Linux ADFS directory entry
	191	*/
	192	static inline void
da23ef05 SS	193	adfs_dir2obj(struct adfs_dir dir, struct object_info obj,
da23ef05 SS	194	struct adfs_direntry *de)
1da177e4	195	{
adb514a4 RK	196	unsigned int name_len;
	197
	198	for (name_len = 0; name_len < ADFS_F_NAME_LEN; name_len++) {
	199	if (de->dirobname[name_len] < ' ')
	200	break;
	201
	202	obj->name[name_len] = de->dirobname[name_len];
	203	}
	204
	205	obj->name_len = name_len;
5ed70bb4	206	obj->indaddr = adfs_readval(de->dirinddiscadd, 3);
1da177e4 LT	207	obj->loadaddr = adfs_readval(de->dirload, 4);
	208	obj->execaddr = adfs_readval(de->direxec, 4);
	209	obj->size = adfs_readval(de->dirlen, 4);
	210	obj->attr = de->newdiratts;
da23ef05	211
411c49bc	212	adfs_object_fixup(dir, obj);
1da177e4 LT	213	}
	214
	215	/*
	216	* convert a Linux ADFS directory entry to a disk-based directory entry
	217	*/
	218	static inline void
	219	adfs_obj2dir(struct adfs_direntry de, struct object_info obj)
	220	{
5ed70bb4	221	adfs_writeval(de->dirinddiscadd, 3, obj->indaddr);
1da177e4 LT	222	adfs_writeval(de->dirload, 4, obj->loadaddr);
	223	adfs_writeval(de->direxec, 4, obj->execaddr);
	224	adfs_writeval(de->dirlen, 4, obj->size);
	225	de->newdiratts = obj->attr;
	226	}
	227
	228	/*
	229	* get a directory entry. Note that the caller is responsible
	230	* for holding the relevant locks.
	231	*/
	232	static int
	233	__adfs_dir_get(struct adfs_dir dir, int pos, struct object_info obj)
	234	{
	235	struct super_block *sb = dir->sb;
	236	struct adfs_direntry de;
	237	int thissize, buffer, offset;
	238
	239	buffer = pos >> sb->s_blocksize_bits;
	240
	241	if (buffer > dir->nr_buffers)
	242	return -EINVAL;
	243
	244	offset = pos & (sb->s_blocksize - 1);
	245	thissize = sb->s_blocksize - offset;
	246	if (thissize > 26)
	247	thissize = 26;
	248
	249	memcpy(&de, dir->bh[buffer]->b_data + offset, thissize);
	250	if (thissize != 26)
	251	memcpy(((char *)&de) + thissize, dir->bh[buffer + 1]->b_data,
	252	26 - thissize);
	253
	254	if (!de.dirobname[0])
	255	return -ENOENT;
	256
da23ef05	257	adfs_dir2obj(dir, obj, &de);
1da177e4 LT	258
	259	return 0;
	260	}
	261
	262	static int
	263	__adfs_dir_put(struct adfs_dir dir, int pos, struct object_info obj)
	264	{
	265	struct super_block *sb = dir->sb;
	266	struct adfs_direntry de;
	267	int thissize, buffer, offset;
	268
	269	buffer = pos >> sb->s_blocksize_bits;
	270
	271	if (buffer > dir->nr_buffers)
	272	return -EINVAL;
	273
	274	offset = pos & (sb->s_blocksize - 1);
	275	thissize = sb->s_blocksize - offset;
	276	if (thissize > 26)
	277	thissize = 26;
	278
	279	/*
	280	* Get the entry in total
	281	*/
	282	memcpy(&de, dir->bh[buffer]->b_data + offset, thissize);
	283	if (thissize != 26)
	284	memcpy(((char *)&de) + thissize, dir->bh[buffer + 1]->b_data,
	285	26 - thissize);
	286
	287	/*
	288	* update it
	289	*/
	290	adfs_obj2dir(&de, obj);
	291
	292	/*
	293	* Put the new entry back
	294	*/
	295	memcpy(dir->bh[buffer]->b_data + offset, &de, thissize);
	296	if (thissize != 26)
	297	memcpy(dir->bh[buffer + 1]->b_data, ((char *)&de) + thissize,
	298	26 - thissize);
	299
	300	return 0;
	301	}
	302
	303	/*
	304	* the caller is responsible for holding the necessary
	305	* locks.
	306	*/
5ed70bb4	307	static int adfs_dir_find_entry(struct adfs_dir *dir, u32 indaddr)
1da177e4 LT	308	{
	309	int pos, ret;
	310
	311	ret = -ENOENT;
	312
	313	for (pos = 5; pos < ADFS_NUM_DIR_ENTRIES * 26 + 5; pos += 26) {
	314	struct object_info obj;
	315
	316	if (!__adfs_dir_get(dir, pos, &obj))
	317	break;
	318
5ed70bb4	319	if (obj.indaddr == indaddr) {
1da177e4 LT	320	ret = pos;
	321	break;
	322	}
	323	}
	324
	325	return ret;
	326	}
	327
5ed70bb4 RK	328	static int adfs_f_read(struct super_block *sb, u32 indaddr, unsigned int size,
5ed70bb4 RK	329	struct adfs_dir *dir)
1da177e4 LT	330	{
	331	int ret;
	332
5ed70bb4	333	if (size != ADFS_NEWDIR_SIZE)
1da177e4 LT	334	return -EIO;
1da177e4 LT	335
5ed70bb4	336	ret = adfs_dir_read(sb, indaddr, size, dir);
1da177e4 LT	337	if (ret)
	338	adfs_error(sb, "unable to read directory");
	339	else
	340	dir->parent_id = adfs_readval(dir->dirtail.new.dirparent, 3);
	341
	342	return ret;
	343	}
	344
	345	static int
	346	adfs_f_setpos(struct adfs_dir *dir, unsigned int fpos)
	347	{
	348	if (fpos >= ADFS_NUM_DIR_ENTRIES)
	349	return -ENOENT;
	350
	351	dir->pos = 5 + fpos * 26;
	352	return 0;
	353	}
	354
	355	static int
	356	adfs_f_getnext(struct adfs_dir dir, struct object_info obj)
	357	{
	358	unsigned int ret;
	359
	360	ret = __adfs_dir_get(dir, dir->pos, obj);
	361	if (ret == 0)
	362	dir->pos += 26;
	363
	364	return ret;
	365	}
	366
	367	static int
	368	adfs_f_update(struct adfs_dir dir, struct object_info obj)
	369	{
	370	struct super_block *sb = dir->sb;
	371	int ret, i;
	372
5ed70bb4	373	ret = adfs_dir_find_entry(dir, obj->indaddr);
1da177e4 LT	374	if (ret < 0) {
	375	adfs_error(dir->sb, "unable to locate entry to update");
	376	goto out;
	377	}
	378
	379	__adfs_dir_put(dir, ret, obj);
	380
	381	/*
	382	* Increment directory sequence number
	383	*/
	384	dir->bh[0]->b_data[0] += 1;
	385	dir->bh[dir->nr_buffers - 1]->b_data[sb->s_blocksize - 6] += 1;
	386
	387	ret = adfs_dir_checkbyte(dir);
	388	/*
	389	* Update directory check byte
	390	*/
	391	dir->bh[dir->nr_buffers - 1]->b_data[sb->s_blocksize - 1] = ret;
	392
	393	#if 1
	394	{
	395	const unsigned int blocksize_bits = sb->s_blocksize_bits;
	396
	397	memcpy(&dir->dirhead, bufoff(dir->bh, 0), sizeof(dir->dirhead));
	398	memcpy(&dir->dirtail, bufoff(dir->bh, 2007), sizeof(dir->dirtail));
	399
	400	if (dir->dirhead.startmasseq != dir->dirtail.new.endmasseq \|\|
	401	memcmp(&dir->dirhead.startname, &dir->dirtail.new.endname, 4))
	402	goto bad_dir;
	403
	404	if (memcmp(&dir->dirhead.startname, "Nick", 4) &&
	405	memcmp(&dir->dirhead.startname, "Hugo", 4))
	406	goto bad_dir;
	407
	408	if (adfs_dir_checkbyte(dir) != dir->dirtail.new.dircheckbyte)
	409	goto bad_dir;
	410	}
	411	#endif
	412	for (i = dir->nr_buffers - 1; i >= 0; i--)
	413	mark_buffer_dirty(dir->bh[i]);
	414
	415	ret = 0;
	416	out:
	417	return ret;
	418	#if 1
	419	bad_dir:
	420	adfs_error(dir->sb, "whoops! I broke a directory!");
	421	return -EIO;
	422	#endif
	423	}
	424
ffdc9064 AV	425	static int
	426	adfs_f_sync(struct adfs_dir *dir)
	427	{
	428	int err = 0;
	429	int i;
	430
	431	for (i = dir->nr_buffers - 1; i >= 0; i--) {
	432	struct buffer_head *bh = dir->bh[i];
	433	sync_dirty_buffer(bh);
	434	if (buffer_req(bh) && !buffer_uptodate(bh))
	435	err = -EIO;
	436	}
	437
	438	return err;
	439	}
	440
1da177e4 LT	441	static void
	442	adfs_f_free(struct adfs_dir *dir)
	443	{
	444	int i;
	445
	446	for (i = dir->nr_buffers - 1; i >= 0; i--) {
	447	brelse(dir->bh[i]);
	448	dir->bh[i] = NULL;
	449	}
	450
	451	dir->nr_buffers = 0;
	452	dir->sb = NULL;
	453	}
	454
0125f504	455	const struct adfs_dir_ops adfs_f_dir_ops = {
1da177e4 LT	456	.read = adfs_f_read,
	457	.setpos = adfs_f_setpos,
	458	.getnext = adfs_f_getnext,
	459	.update = adfs_f_update,
ffdc9064	460	.sync = adfs_f_sync,
1da177e4 LT	461	.free = adfs_f_free
1da177e4 LT	462	};