[linux.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 <linux/buffer_head.h>
#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, unsigned long object_id,
	      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, object_id, blk);
		if (!phys) {
			adfs_error(sb, "dir object %lX has a hole at offset %d",
				   object_id, 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, "corrupted directory fragment %lX",
		   object_id);
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->file_id  = 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->file_id);
	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, unsigned long object_id)
{
	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.file_id == object_id) {
			ret = pos;
			break;
		}
	}

	return ret;
}

static int
adfs_f_read(struct super_block *sb, unsigned int id, unsigned int sz, struct adfs_dir *dir)
{
	int ret;

	if (sz != ADFS_NEWDIR_SIZE)
		return -EIO;

	ret = adfs_dir_read(sb, id, sz, 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->file_id);
	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	9	#include <linux/buffer_head.h>
1da177e4 LT	10	#include "adfs.h"
	11	#include "dir_f.h"
	12
	13	static void adfs_f_free(struct adfs_dir *dir);
	14
	15	/*
	16	* Read an (unaligned) value of length 1..4 bytes
	17	*/
	18	static inline unsigned int adfs_readval(unsigned char *p, int len)
	19	{
	20	unsigned int val = 0;
	21
	22	switch (len) {
	23	case 4: val \|= p[3] << 24;
74f79099	24	/* fall through */
1da177e4	25	case 3: val \|= p[2] << 16;
74f79099	26	/* fall through */
1da177e4	27	case 2: val \|= p[1] << 8;
74f79099	28	/* fall through */
1da177e4 LT	29	default: val \|= p[0];
	30	}
	31	return val;
	32	}
	33
	34	static inline void adfs_writeval(unsigned char *p, int len, unsigned int val)
	35	{
	36	switch (len) {
	37	case 4: p[3] = val >> 24;
74f79099	38	/* fall through */
1da177e4	39	case 3: p[2] = val >> 16;
74f79099	40	/* fall through */
1da177e4	41	case 2: p[1] = val >> 8;
74f79099	42	/* fall through */
1da177e4 LT	43	default: p[0] = val;
	44	}
	45	}
	46
1da177e4 LT	47	#define ror13(v) ((v >> 13) \| (v << 19))
	48
	49	#define dir_u8(idx) \
	50	({ int _buf = idx >> blocksize_bits; \
	51	int _off = idx - (_buf << blocksize_bits);\
	52	(u8 )(bh[_buf]->b_data + _off); \
	53	})
	54
	55	#define dir_u32(idx) \
	56	({ int _buf = idx >> blocksize_bits; \
	57	int _off = idx - (_buf << blocksize_bits);\
	58	(__le32 )(bh[_buf]->b_data + _off); \
	59	})
	60
	61	#define bufoff(_bh,_idx) \
	62	({ int _buf = _idx >> blocksize_bits; \
	63	int _off = _idx - (_buf << blocksize_bits);\
	64	(u8 *)(_bh[_buf]->b_data + _off); \
	65	})
	66
	67	/*
	68	* There are some algorithms that are nice in
	69	* assembler, but a bitch in C... This is one
	70	* of them.
	71	*/
	72	static u8
	73	adfs_dir_checkbyte(const struct adfs_dir *dir)
	74	{
	75	struct buffer_head * const *bh = dir->bh;
	76	const int blocksize_bits = dir->sb->s_blocksize_bits;
	77	union { __le32 ptr32; u8 ptr8; } ptr, end;
	78	u32 dircheck = 0;
	79	int last = 5 - 26;
	80	int i = 0;
	81
	82	/*
	83	* Accumulate each word up to the last whole
	84	* word of the last directory entry. This
	85	* can spread across several buffer heads.
	86	*/
	87	do {
	88	last += 26;
	89	do {
	90	dircheck = le32_to_cpu(dir_u32(i)) ^ ror13(dircheck);
	91
	92	i += sizeof(u32);
	93	} while (i < (last & ~3));
	94	} while (dir_u8(last) != 0);
	95
	96	/*
	97	* Accumulate the last few bytes. These
	98	* bytes will be within the same bh.
	99	*/
	100	if (i != last) {
	101	ptr.ptr8 = bufoff(bh, i);
	102	end.ptr8 = ptr.ptr8 + last - i;
	103
e5949050	104	do {
1da177e4	105	dircheck = *ptr.ptr8++ ^ ror13(dircheck);
e5949050	106	} while (ptr.ptr8 < end.ptr8);
1da177e4 LT	107	}
	108
	109	/*
	110	* The directory tail is in the final bh
	111	* Note that contary to the RISC OS PRMs,
	112	* the first few bytes are NOT included
	113	* in the check. All bytes are in the
	114	* same bh.
	115	*/
	116	ptr.ptr8 = bufoff(bh, 2008);
	117	end.ptr8 = ptr.ptr8 + 36;
	118
	119	do {
	120	__le32 v = *ptr.ptr32++;
	121	dircheck = le32_to_cpu(v) ^ ror13(dircheck);
	122	} while (ptr.ptr32 < end.ptr32);
	123
	124	return (dircheck ^ (dircheck >> 8) ^ (dircheck >> 16) ^ (dircheck >> 24)) & 0xff;
	125	}
	126
	127	/*
	128	* Read and check that a directory is valid
	129	*/
	130	static int
	131	adfs_dir_read(struct super_block *sb, unsigned long object_id,
	132	unsigned int size, struct adfs_dir *dir)
	133	{
	134	const unsigned int blocksize_bits = sb->s_blocksize_bits;
	135	int blk = 0;
	136
	137	/*
	138	* Directories which are not a multiple of 2048 bytes
	139	* are considered bad v2 [3.6]
	140	*/
	141	if (size & 2047)
	142	goto bad_dir;
	143
	144	size >>= blocksize_bits;
	145
	146	dir->nr_buffers = 0;
	147	dir->sb = sb;
	148
	149	for (blk = 0; blk < size; blk++) {
	150	int phys;
	151
	152	phys = __adfs_block_map(sb, object_id, blk);
	153	if (!phys) {
	154	adfs_error(sb, "dir object %lX has a hole at offset %d",
	155	object_id, blk);
	156	goto release_buffers;
	157	}
	158
	159	dir->bh[blk] = sb_bread(sb, phys);
	160	if (!dir->bh[blk])
	161	goto release_buffers;
	162	}
	163
	164	memcpy(&dir->dirhead, bufoff(dir->bh, 0), sizeof(dir->dirhead));
	165	memcpy(&dir->dirtail, bufoff(dir->bh, 2007), sizeof(dir->dirtail));
	166
	167	if (dir->dirhead.startmasseq != dir->dirtail.new.endmasseq \|\|
	168	memcmp(&dir->dirhead.startname, &dir->dirtail.new.endname, 4))
	169	goto bad_dir;
	170
171	if (memcmp(&dir->dirhead.startname, "Nick", 4) &&
172	memcmp(&dir->dirhead.startname, "Hugo", 4))
173	goto bad_dir;
174
175	if (adfs_dir_checkbyte(dir) != dir->dirtail.new.dircheckbyte)
176	goto bad_dir;
177
178	dir->nr_buffers = blk;
179
180	return 0;
181
182	bad_dir:
183	adfs_error(sb, "corrupted directory fragment %lX",
184	object_id);
185	release_buffers:
186	for (blk -= 1; blk >= 0; blk -= 1)
187	brelse(dir->bh[blk]);
188
189	dir->sb = NULL;
190
191	return -EIO;
192	}
193
194	/*
195	* convert a disk-based directory entry to a Linux ADFS directory entry
196	*/
197	static inline void
da23ef05 SS	198	adfs_dir2obj(struct adfs_dir dir, struct object_info obj,
da23ef05 SS	199	struct adfs_direntry *de)
1da177e4	200	{
adb514a4 RK	201	unsigned int name_len;
	202
	203	for (name_len = 0; name_len < ADFS_F_NAME_LEN; name_len++) {
	204	if (de->dirobname[name_len] < ' ')
	205	break;
	206
	207	obj->name[name_len] = de->dirobname[name_len];
	208	}
	209
	210	obj->name_len = name_len;
1da177e4 LT	211	obj->file_id = adfs_readval(de->dirinddiscadd, 3);
	212	obj->loadaddr = adfs_readval(de->dirload, 4);
	213	obj->execaddr = adfs_readval(de->direxec, 4);
	214	obj->size = adfs_readval(de->dirlen, 4);
	215	obj->attr = de->newdiratts;
da23ef05	216
411c49bc	217	adfs_object_fixup(dir, obj);
1da177e4 LT	218	}
	219
	220	/*
	221	* convert a Linux ADFS directory entry to a disk-based directory entry
	222	*/
	223	static inline void
	224	adfs_obj2dir(struct adfs_direntry de, struct object_info obj)
	225	{
	226	adfs_writeval(de->dirinddiscadd, 3, obj->file_id);
	227	adfs_writeval(de->dirload, 4, obj->loadaddr);
	228	adfs_writeval(de->direxec, 4, obj->execaddr);
	229	adfs_writeval(de->dirlen, 4, obj->size);
	230	de->newdiratts = obj->attr;
	231	}
	232
	233	/*
	234	* get a directory entry. Note that the caller is responsible
	235	* for holding the relevant locks.
	236	*/
	237	static int
	238	__adfs_dir_get(struct adfs_dir dir, int pos, struct object_info obj)
	239	{
	240	struct super_block *sb = dir->sb;
	241	struct adfs_direntry de;
	242	int thissize, buffer, offset;
	243
	244	buffer = pos >> sb->s_blocksize_bits;
	245
	246	if (buffer > dir->nr_buffers)
	247	return -EINVAL;
	248
	249	offset = pos & (sb->s_blocksize - 1);
	250	thissize = sb->s_blocksize - offset;
	251	if (thissize > 26)
	252	thissize = 26;
	253
	254	memcpy(&de, dir->bh[buffer]->b_data + offset, thissize);
	255	if (thissize != 26)
	256	memcpy(((char *)&de) + thissize, dir->bh[buffer + 1]->b_data,
	257	26 - thissize);
	258
	259	if (!de.dirobname[0])
	260	return -ENOENT;
	261
da23ef05	262	adfs_dir2obj(dir, obj, &de);
1da177e4 LT	263
	264	return 0;
	265	}
	266
	267	static int
	268	__adfs_dir_put(struct adfs_dir dir, int pos, struct object_info obj)
	269	{
	270	struct super_block *sb = dir->sb;
	271	struct adfs_direntry de;
	272	int thissize, buffer, offset;
	273
	274	buffer = pos >> sb->s_blocksize_bits;
	275
	276	if (buffer > dir->nr_buffers)
	277	return -EINVAL;
	278
	279	offset = pos & (sb->s_blocksize - 1);
	280	thissize = sb->s_blocksize - offset;
	281	if (thissize > 26)
	282	thissize = 26;
	283
	284	/*
	285	* Get the entry in total
	286	*/
	287	memcpy(&de, dir->bh[buffer]->b_data + offset, thissize);
	288	if (thissize != 26)
	289	memcpy(((char *)&de) + thissize, dir->bh[buffer + 1]->b_data,
	290	26 - thissize);
	291
	292	/*
	293	* update it
	294	*/
	295	adfs_obj2dir(&de, obj);
	296
	297	/*
	298	* Put the new entry back
	299	*/
	300	memcpy(dir->bh[buffer]->b_data + offset, &de, thissize);
	301	if (thissize != 26)
	302	memcpy(dir->bh[buffer + 1]->b_data, ((char *)&de) + thissize,
	303	26 - thissize);
	304
	305	return 0;
	306	}
	307
	308	/*
	309	* the caller is responsible for holding the necessary
	310	* locks.
	311	*/
	312	static int
	313	adfs_dir_find_entry(struct adfs_dir *dir, unsigned long object_id)
	314	{
	315	int pos, ret;
	316
	317	ret = -ENOENT;
	318
	319	for (pos = 5; pos < ADFS_NUM_DIR_ENTRIES * 26 + 5; pos += 26) {
	320	struct object_info obj;
	321
	322	if (!__adfs_dir_get(dir, pos, &obj))
	323	break;
	324
	325	if (obj.file_id == object_id) {
	326	ret = pos;
327	break;
328	}
329	}
330
331	return ret;
332	}
333
334	static int
335	adfs_f_read(struct super_block sb, unsigned int id, unsigned int sz, struct adfs_dir dir)
336	{
337	int ret;
338
339	if (sz != ADFS_NEWDIR_SIZE)
340	return -EIO;
341
342	ret = adfs_dir_read(sb, id, sz, dir);
343	if (ret)
344	adfs_error(sb, "unable to read directory");
345	else
346	dir->parent_id = adfs_readval(dir->dirtail.new.dirparent, 3);
347
348	return ret;
349	}
350
351	static int
352	adfs_f_setpos(struct adfs_dir *dir, unsigned int fpos)
353	{
354	if (fpos >= ADFS_NUM_DIR_ENTRIES)
355	return -ENOENT;
356
357	dir->pos = 5 + fpos * 26;
358	return 0;
359	}
360
361	static int
362	adfs_f_getnext(struct adfs_dir dir, struct object_info obj)
363	{
364	unsigned int ret;
365
366	ret = __adfs_dir_get(dir, dir->pos, obj);
367	if (ret == 0)
368	dir->pos += 26;
369
370	return ret;
371	}
372
373	static int
374	adfs_f_update(struct adfs_dir dir, struct object_info obj)
375	{
376	struct super_block *sb = dir->sb;
377	int ret, i;
378
379	ret = adfs_dir_find_entry(dir, obj->file_id);
380	if (ret < 0) {
381	adfs_error(dir->sb, "unable to locate entry to update");
382	goto out;
383	}
384
385	__adfs_dir_put(dir, ret, obj);
386
387	/*
388	* Increment directory sequence number
389	*/
390	dir->bh[0]->b_data[0] += 1;
391	dir->bh[dir->nr_buffers - 1]->b_data[sb->s_blocksize - 6] += 1;
392
393	ret = adfs_dir_checkbyte(dir);
394	/*
395	* Update directory check byte
396	*/
397	dir->bh[dir->nr_buffers - 1]->b_data[sb->s_blocksize - 1] = ret;
398
399	#if 1
400	{
401	const unsigned int blocksize_bits = sb->s_blocksize_bits;
402
403	memcpy(&dir->dirhead, bufoff(dir->bh, 0), sizeof(dir->dirhead));
404	memcpy(&dir->dirtail, bufoff(dir->bh, 2007), sizeof(dir->dirtail));
405
406	if (dir->dirhead.startmasseq != dir->dirtail.new.endmasseq \|\|
407	memcmp(&dir->dirhead.startname, &dir->dirtail.new.endname, 4))
408	goto bad_dir;
409
410	if (memcmp(&dir->dirhead.startname, "Nick", 4) &&
411	memcmp(&dir->dirhead.startname, "Hugo", 4))
412	goto bad_dir;
413
414	if (adfs_dir_checkbyte(dir) != dir->dirtail.new.dircheckbyte)
415	goto bad_dir;
416	}
417	#endif
418	for (i = dir->nr_buffers - 1; i >= 0; i--)
419	mark_buffer_dirty(dir->bh[i]);
420
421	ret = 0;
422	out:
423	return ret;
424	#if 1
425	bad_dir:
426	adfs_error(dir->sb, "whoops! I broke a directory!");
427	return -EIO;
428	#endif
429	}
430
ffdc9064 AV	431	static int
	432	adfs_f_sync(struct adfs_dir *dir)
	433	{
	434	int err = 0;
	435	int i;
	436
	437	for (i = dir->nr_buffers - 1; i >= 0; i--) {
	438	struct buffer_head *bh = dir->bh[i];
	439	sync_dirty_buffer(bh);
	440	if (buffer_req(bh) && !buffer_uptodate(bh))
	441	err = -EIO;
	442	}
	443
	444	return err;
	445	}
	446
1da177e4 LT	447	static void
	448	adfs_f_free(struct adfs_dir *dir)
	449	{
	450	int i;
	451
	452	for (i = dir->nr_buffers - 1; i >= 0; i--) {
	453	brelse(dir->bh[i]);
	454	dir->bh[i] = NULL;
	455	}
	456
	457	dir->nr_buffers = 0;
	458	dir->sb = NULL;
	459	}
	460
0125f504	461	const struct adfs_dir_ops adfs_f_dir_ops = {
1da177e4 LT	462	.read = adfs_f_read,
	463	.setpos = adfs_f_setpos,
	464	.getnext = adfs_f_getnext,
	465	.update = adfs_f_update,
ffdc9064	466	.sync = adfs_f_sync,
1da177e4 LT	467	.free = adfs_f_free
1da177e4 LT	468	};