[net-next-2.6.git] / fs / adfs / dir_f.c

/*
 *  linux/fs/adfs/dir_f.c
 *
 * Copyright (C) 1997-1999 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 *  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;
	case 3:		val |= p[2] << 16;
	case 2:		val |= p[1] << 8;
	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;
	case 3:		p[2] = val >> 16;
	case 2:		p[1] = val >> 8;
	default:	p[0] = val;
	}
}

static inline int adfs_readname(char *buf, char *ptr, int maxlen)
{
	char *old_buf = buf;

	while ((unsigned char)*ptr >= ' ' && maxlen--) {
		if (*ptr == '/')
			*buf++ = '.';
		else
			*buf++ = *ptr;
		ptr++;
	}
	*buf = '\0';

	return buf - old_buf;
}

#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 object_info *obj, struct adfs_direntry *de)
{
	obj->name_len =	adfs_readname(obj->name, de->dirobname, ADFS_F_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;
}

/*
 * 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(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;
}

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
1da177e4 LT	1	/*
	2	* linux/fs/adfs/dir_f.c
	3	*
	4	* Copyright (C) 1997-1999 Russell King
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	* E and F format directory handling
	11	*/
1da177e4	12	#include <linux/buffer_head.h>
1da177e4 LT	13	#include "adfs.h"
	14	#include "dir_f.h"
	15
	16	static void adfs_f_free(struct adfs_dir *dir);
	17
	18	/*
	19	* Read an (unaligned) value of length 1..4 bytes
	20	*/
	21	static inline unsigned int adfs_readval(unsigned char *p, int len)
	22	{
	23	unsigned int val = 0;
	24
	25	switch (len) {
	26	case 4: val \|= p[3] << 24;
	27	case 3: val \|= p[2] << 16;
	28	case 2: val \|= p[1] << 8;
	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;
	38	case 3: p[2] = val >> 16;
	39	case 2: p[1] = val >> 8;
	40	default: p[0] = val;
	41	}
	42	}
	43
	44	static inline int adfs_readname(char buf, char ptr, int maxlen)
	45	{
	46	char *old_buf = buf;
	47
3223ea8c	48	while ((unsigned char)*ptr >= ' ' && maxlen--) {
1da177e4 LT	49	if (*ptr == '/')
	50	*buf++ = '.';
	51	else
	52	buf++ = ptr;
	53	ptr++;
	54	}
	55	*buf = '\0';
	56
	57	return buf - old_buf;
	58	}
	59
	60	#define ror13(v) ((v >> 13) \| (v << 19))
	61
	62	#define dir_u8(idx) \
	63	({ int _buf = idx >> blocksize_bits; \
	64	int _off = idx - (_buf << blocksize_bits);\
	65	(u8 )(bh[_buf]->b_data + _off); \
	66	})
	67
	68	#define dir_u32(idx) \
	69	({ int _buf = idx >> blocksize_bits; \
	70	int _off = idx - (_buf << blocksize_bits);\
	71	(__le32 )(bh[_buf]->b_data + _off); \
	72	})
	73
	74	#define bufoff(_bh,_idx) \
	75	({ int _buf = _idx >> blocksize_bits; \
	76	int _off = _idx - (_buf << blocksize_bits);\
	77	(u8 *)(_bh[_buf]->b_data + _off); \
	78	})
	79
	80	/*
	81	* There are some algorithms that are nice in
	82	* assembler, but a bitch in C... This is one
	83	* of them.
	84	*/
	85	static u8
	86	adfs_dir_checkbyte(const struct adfs_dir *dir)
	87	{
	88	struct buffer_head * const *bh = dir->bh;
	89	const int blocksize_bits = dir->sb->s_blocksize_bits;
	90	union { __le32 ptr32; u8 ptr8; } ptr, end;
	91	u32 dircheck = 0;
	92	int last = 5 - 26;
	93	int i = 0;
	94
	95	/*
	96	* Accumulate each word up to the last whole
	97	* word of the last directory entry. This
	98	* can spread across several buffer heads.
	99	*/
	100	do {
	101	last += 26;
	102	do {
	103	dircheck = le32_to_cpu(dir_u32(i)) ^ ror13(dircheck);
	104
	105	i += sizeof(u32);
	106	} while (i < (last & ~3));
	107	} while (dir_u8(last) != 0);
	108
	109	/*
	110	* Accumulate the last few bytes. These
	111	* bytes will be within the same bh.
	112	*/
113	if (i != last) {
114	ptr.ptr8 = bufoff(bh, i);
115	end.ptr8 = ptr.ptr8 + last - i;
116
e5949050	117	do {
1da177e4	118	dircheck = *ptr.ptr8++ ^ ror13(dircheck);
e5949050	119	} while (ptr.ptr8 < end.ptr8);
1da177e4 LT	120	}
	121
	122	/*
	123	* The directory tail is in the final bh
	124	* Note that contary to the RISC OS PRMs,
	125	* the first few bytes are NOT included
	126	* in the check. All bytes are in the
	127	* same bh.
	128	*/
	129	ptr.ptr8 = bufoff(bh, 2008);
	130	end.ptr8 = ptr.ptr8 + 36;
	131
	132	do {
	133	__le32 v = *ptr.ptr32++;
	134	dircheck = le32_to_cpu(v) ^ ror13(dircheck);
	135	} while (ptr.ptr32 < end.ptr32);
	136
	137	return (dircheck ^ (dircheck >> 8) ^ (dircheck >> 16) ^ (dircheck >> 24)) & 0xff;
	138	}
	139
	140	/*
	141	* Read and check that a directory is valid
	142	*/
	143	static int
	144	adfs_dir_read(struct super_block *sb, unsigned long object_id,
	145	unsigned int size, struct adfs_dir *dir)
	146	{
	147	const unsigned int blocksize_bits = sb->s_blocksize_bits;
	148	int blk = 0;
	149
	150	/*
	151	* Directories which are not a multiple of 2048 bytes
	152	* are considered bad v2 [3.6]
	153	*/
	154	if (size & 2047)
	155	goto bad_dir;
	156
	157	size >>= blocksize_bits;
	158
	159	dir->nr_buffers = 0;
	160	dir->sb = sb;
	161
	162	for (blk = 0; blk < size; blk++) {
	163	int phys;
	164
	165	phys = __adfs_block_map(sb, object_id, blk);
	166	if (!phys) {
	167	adfs_error(sb, "dir object %lX has a hole at offset %d",
	168	object_id, blk);
	169	goto release_buffers;
	170	}
	171
	172	dir->bh[blk] = sb_bread(sb, phys);
	173	if (!dir->bh[blk])
	174	goto release_buffers;
	175	}
	176
	177	memcpy(&dir->dirhead, bufoff(dir->bh, 0), sizeof(dir->dirhead));
	178	memcpy(&dir->dirtail, bufoff(dir->bh, 2007), sizeof(dir->dirtail));
	179
	180	if (dir->dirhead.startmasseq != dir->dirtail.new.endmasseq \|\|
	181	memcmp(&dir->dirhead.startname, &dir->dirtail.new.endname, 4))
	182	goto bad_dir;
	183
184	if (memcmp(&dir->dirhead.startname, "Nick", 4) &&
185	memcmp(&dir->dirhead.startname, "Hugo", 4))
186	goto bad_dir;
187
188	if (adfs_dir_checkbyte(dir) != dir->dirtail.new.dircheckbyte)
189	goto bad_dir;
190
191	dir->nr_buffers = blk;
192
193	return 0;
194
195	bad_dir:
196	adfs_error(sb, "corrupted directory fragment %lX",
197	object_id);
198	release_buffers:
199	for (blk -= 1; blk >= 0; blk -= 1)
200	brelse(dir->bh[blk]);
201
202	dir->sb = NULL;
203
204	return -EIO;
205	}
206
207	/*
208	* convert a disk-based directory entry to a Linux ADFS directory entry
209	*/
210	static inline void
211	adfs_dir2obj(struct object_info obj, struct adfs_direntry de)
212	{
213	obj->name_len = adfs_readname(obj->name, de->dirobname, ADFS_F_NAME_LEN);
214	obj->file_id = adfs_readval(de->dirinddiscadd, 3);
215	obj->loadaddr = adfs_readval(de->dirload, 4);
216	obj->execaddr = adfs_readval(de->direxec, 4);
217	obj->size = adfs_readval(de->dirlen, 4);
218	obj->attr = de->newdiratts;
219	}
220
221	/*
222	* convert a Linux ADFS directory entry to a disk-based directory entry
223	*/
224	static inline void
225	adfs_obj2dir(struct adfs_direntry de, struct object_info obj)
226	{
227	adfs_writeval(de->dirinddiscadd, 3, obj->file_id);
228	adfs_writeval(de->dirload, 4, obj->loadaddr);
229	adfs_writeval(de->direxec, 4, obj->execaddr);
230	adfs_writeval(de->dirlen, 4, obj->size);
231	de->newdiratts = obj->attr;
232	}
233
234	/*
235	* get a directory entry. Note that the caller is responsible
236	* for holding the relevant locks.
237	*/
238	static int
239	__adfs_dir_get(struct adfs_dir dir, int pos, struct object_info obj)
240	{
241	struct super_block *sb = dir->sb;
242	struct adfs_direntry de;
243	int thissize, buffer, offset;
244
245	buffer = pos >> sb->s_blocksize_bits;
246
247	if (buffer > dir->nr_buffers)
248	return -EINVAL;
249
250	offset = pos & (sb->s_blocksize - 1);
251	thissize = sb->s_blocksize - offset;
252	if (thissize > 26)
253	thissize = 26;
254
255	memcpy(&de, dir->bh[buffer]->b_data + offset, thissize);
256	if (thissize != 26)
257	memcpy(((char *)&de) + thissize, dir->bh[buffer + 1]->b_data,
258	26 - thissize);
259
260	if (!de.dirobname[0])
261	return -ENOENT;
262
263	adfs_dir2obj(obj, &de);
264
265	return 0;
266	}
267
268	static int
269	__adfs_dir_put(struct adfs_dir dir, int pos, struct object_info obj)
270	{
271	struct super_block *sb = dir->sb;
272	struct adfs_direntry de;
273	int thissize, buffer, offset;
274
275	buffer = pos >> sb->s_blocksize_bits;
276
277	if (buffer > dir->nr_buffers)
278	return -EINVAL;
279
280	offset = pos & (sb->s_blocksize - 1);
281	thissize = sb->s_blocksize - offset;
282	if (thissize > 26)
283	thissize = 26;
284
285	/*
286	* Get the entry in total
287	*/
288	memcpy(&de, dir->bh[buffer]->b_data + offset, thissize);
289	if (thissize != 26)
290	memcpy(((char *)&de) + thissize, dir->bh[buffer + 1]->b_data,
291	26 - thissize);
292
293	/*
294	* update it
295	*/
296	adfs_obj2dir(&de, obj);
297
298	/*
299	* Put the new entry back
300	*/
301	memcpy(dir->bh[buffer]->b_data + offset, &de, thissize);
302	if (thissize != 26)
303	memcpy(dir->bh[buffer + 1]->b_data, ((char *)&de) + thissize,
304	26 - thissize);
305
306	return 0;
307	}
308
309	/*
310	* the caller is responsible for holding the necessary
311	* locks.
312	*/
313	static int
314	adfs_dir_find_entry(struct adfs_dir *dir, unsigned long object_id)
315	{
316	int pos, ret;
317
318	ret = -ENOENT;
319
320	for (pos = 5; pos < ADFS_NUM_DIR_ENTRIES * 26 + 5; pos += 26) {
321	struct object_info obj;
322
323	if (!__adfs_dir_get(dir, pos, &obj))
324	break;
325
326	if (obj.file_id == object_id) {
327	ret = pos;
328	break;
329	}
330	}
331
332	return ret;
333	}
334
335	static int
336	adfs_f_read(struct super_block sb, unsigned int id, unsigned int sz, struct adfs_dir dir)
337	{
338	int ret;
339
340	if (sz != ADFS_NEWDIR_SIZE)
341	return -EIO;
342
343	ret = adfs_dir_read(sb, id, sz, dir);
344	if (ret)
345	adfs_error(sb, "unable to read directory");
346	else
347	dir->parent_id = adfs_readval(dir->dirtail.new.dirparent, 3);
348
349	return ret;
350	}
351
352	static int
353	adfs_f_setpos(struct adfs_dir *dir, unsigned int fpos)
354	{
355	if (fpos >= ADFS_NUM_DIR_ENTRIES)
356	return -ENOENT;
357
358	dir->pos = 5 + fpos * 26;
359	return 0;
360	}
361
362	static int
363	adfs_f_getnext(struct adfs_dir dir, struct object_info obj)
364	{
365	unsigned int ret;
366
367	ret = __adfs_dir_get(dir, dir->pos, obj);
368	if (ret == 0)
369	dir->pos += 26;
370
371	return ret;
372	}
373
374	static int
375	adfs_f_update(struct adfs_dir dir, struct object_info obj)
376	{
377	struct super_block *sb = dir->sb;
378	int ret, i;
379
380	ret = adfs_dir_find_entry(dir, obj->file_id);
381	if (ret < 0) {
382	adfs_error(dir->sb, "unable to locate entry to update");
383	goto out;
384	}
385
386	__adfs_dir_put(dir, ret, obj);
387
388	/*
389	* Increment directory sequence number
390	*/
391	dir->bh[0]->b_data[0] += 1;
392	dir->bh[dir->nr_buffers - 1]->b_data[sb->s_blocksize - 6] += 1;
393
394	ret = adfs_dir_checkbyte(dir);
395	/*
396	* Update directory check byte
397	*/
398	dir->bh[dir->nr_buffers - 1]->b_data[sb->s_blocksize - 1] = ret;
399
400	#if 1
401	{
402	const unsigned int blocksize_bits = sb->s_blocksize_bits;
403
404	memcpy(&dir->dirhead, bufoff(dir->bh, 0), sizeof(dir->dirhead));
405	memcpy(&dir->dirtail, bufoff(dir->bh, 2007), sizeof(dir->dirtail));
406
407	if (dir->dirhead.startmasseq != dir->dirtail.new.endmasseq \|\|
408	memcmp(&dir->dirhead.startname, &dir->dirtail.new.endname, 4))
409	goto bad_dir;
410
411	if (memcmp(&dir->dirhead.startname, "Nick", 4) &&
412	memcmp(&dir->dirhead.startname, "Hugo", 4))
413	goto bad_dir;
414
415	if (adfs_dir_checkbyte(dir) != dir->dirtail.new.dircheckbyte)
416	goto bad_dir;
417	}
418	#endif
419	for (i = dir->nr_buffers - 1; i >= 0; i--)
420	mark_buffer_dirty(dir->bh[i]);
421
422	ret = 0;
423	out:
424	return ret;
425	#if 1
426	bad_dir:
427	adfs_error(dir->sb, "whoops! I broke a directory!");
428	return -EIO;
429	#endif
430	}
431
ffdc9064 AV	432	static int
	433	adfs_f_sync(struct adfs_dir *dir)
	434	{
	435	int err = 0;
	436	int i;
	437
	438	for (i = dir->nr_buffers - 1; i >= 0; i--) {
	439	struct buffer_head *bh = dir->bh[i];
	440	sync_dirty_buffer(bh);
	441	if (buffer_req(bh) && !buffer_uptodate(bh))
	442	err = -EIO;
	443	}
	444
	445	return err;
	446	}
	447
1da177e4 LT	448	static void
	449	adfs_f_free(struct adfs_dir *dir)
	450	{
	451	int i;
	452
	453	for (i = dir->nr_buffers - 1; i >= 0; i--) {
	454	brelse(dir->bh[i]);
	455	dir->bh[i] = NULL;
	456	}
	457
	458	dir->nr_buffers = 0;
	459	dir->sb = NULL;
	460	}
	461
	462	struct adfs_dir_ops adfs_f_dir_ops = {
	463	.read = adfs_f_read,
	464	.setpos = adfs_f_setpos,
	465	.getnext = adfs_f_getnext,
	466	.update = adfs_f_update,
ffdc9064	467	.sync = adfs_f_sync,
1da177e4 LT	468	.free = adfs_f_free
1da177e4 LT	469	};