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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 */
12#include <linux/buffer_head.h>
13#include "adfs.h"
14#include "dir_f.h"
15
16static void adfs_f_free(struct adfs_dir *dir);
17
18/*
19 * Read an (unaligned) value of length 1..4 bytes
20 */
21static 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
34static 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
44static inline int adfs_readname(char *buf, char *ptr, int maxlen)
45{
46 char *old_buf = buf;
47
48 while ((unsigned char)*ptr >= ' ' && maxlen--) {
49 if (*ptr == '/')
50 *buf++ = '.';
51 else
52 *buf++ = *ptr;
53 ptr++;
54 }
55
56 return buf - old_buf;
57}
58
59#define ror13(v) ((v >> 13) | (v << 19))
60
61#define dir_u8(idx) \
62 ({ int _buf = idx >> blocksize_bits; \
63 int _off = idx - (_buf << blocksize_bits);\
64 *(u8 *)(bh[_buf]->b_data + _off); \
65 })
66
67#define dir_u32(idx) \
68 ({ int _buf = idx >> blocksize_bits; \
69 int _off = idx - (_buf << blocksize_bits);\
70 *(__le32 *)(bh[_buf]->b_data + _off); \
71 })
72
73#define bufoff(_bh,_idx) \
74 ({ int _buf = _idx >> blocksize_bits; \
75 int _off = _idx - (_buf << blocksize_bits);\
76 (u8 *)(_bh[_buf]->b_data + _off); \
77 })
78
79/*
80 * There are some algorithms that are nice in
81 * assembler, but a bitch in C... This is one
82 * of them.
83 */
84static u8
85adfs_dir_checkbyte(const struct adfs_dir *dir)
86{
87 struct buffer_head * const *bh = dir->bh;
88 const int blocksize_bits = dir->sb->s_blocksize_bits;
89 union { __le32 *ptr32; u8 *ptr8; } ptr, end;
90 u32 dircheck = 0;
91 int last = 5 - 26;
92 int i = 0;
93
94 /*
95 * Accumulate each word up to the last whole
96 * word of the last directory entry. This
97 * can spread across several buffer heads.
98 */
99 do {
100 last += 26;
101 do {
102 dircheck = le32_to_cpu(dir_u32(i)) ^ ror13(dircheck);
103
104 i += sizeof(u32);
105 } while (i < (last & ~3));
106 } while (dir_u8(last) != 0);
107
108 /*
109 * Accumulate the last few bytes. These
110 * bytes will be within the same bh.
111 */
112 if (i != last) {
113 ptr.ptr8 = bufoff(bh, i);
114 end.ptr8 = ptr.ptr8 + last - i;
115
116 do {
117 dircheck = *ptr.ptr8++ ^ ror13(dircheck);
118 } while (ptr.ptr8 < end.ptr8);
119 }
120
121 /*
122 * The directory tail is in the final bh
123 * Note that contary to the RISC OS PRMs,
124 * the first few bytes are NOT included
125 * in the check. All bytes are in the
126 * same bh.
127 */
128 ptr.ptr8 = bufoff(bh, 2008);
129 end.ptr8 = ptr.ptr8 + 36;
130
131 do {
132 __le32 v = *ptr.ptr32++;
133 dircheck = le32_to_cpu(v) ^ ror13(dircheck);
134 } while (ptr.ptr32 < end.ptr32);
135
136 return (dircheck ^ (dircheck >> 8) ^ (dircheck >> 16) ^ (dircheck >> 24)) & 0xff;
137}
138
139/*
140 * Read and check that a directory is valid
141 */
142static int
143adfs_dir_read(struct super_block *sb, unsigned long object_id,
144 unsigned int size, struct adfs_dir *dir)
145{
146 const unsigned int blocksize_bits = sb->s_blocksize_bits;
147 int blk = 0;
148
149 /*
150 * Directories which are not a multiple of 2048 bytes
151 * are considered bad v2 [3.6]
152 */
153 if (size & 2047)
154 goto bad_dir;
155
156 size >>= blocksize_bits;
157
158 dir->nr_buffers = 0;
159 dir->sb = sb;
160
161 for (blk = 0; blk < size; blk++) {
162 int phys;
163
164 phys = __adfs_block_map(sb, object_id, blk);
165 if (!phys) {
166 adfs_error(sb, "dir object %lX has a hole at offset %d",
167 object_id, blk);
168 goto release_buffers;
169 }
170
171 dir->bh[blk] = sb_bread(sb, phys);
172 if (!dir->bh[blk])
173 goto release_buffers;
174 }
175
176 memcpy(&dir->dirhead, bufoff(dir->bh, 0), sizeof(dir->dirhead));
177 memcpy(&dir->dirtail, bufoff(dir->bh, 2007), sizeof(dir->dirtail));
178
179 if (dir->dirhead.startmasseq != dir->dirtail.new.endmasseq ||
180 memcmp(&dir->dirhead.startname, &dir->dirtail.new.endname, 4))
181 goto bad_dir;
182
183 if (memcmp(&dir->dirhead.startname, "Nick", 4) &&
184 memcmp(&dir->dirhead.startname, "Hugo", 4))
185 goto bad_dir;
186
187 if (adfs_dir_checkbyte(dir) != dir->dirtail.new.dircheckbyte)
188 goto bad_dir;
189
190 dir->nr_buffers = blk;
191
192 return 0;
193
194bad_dir:
195 adfs_error(sb, "corrupted directory fragment %lX",
196 object_id);
197release_buffers:
198 for (blk -= 1; blk >= 0; blk -= 1)
199 brelse(dir->bh[blk]);
200
201 dir->sb = NULL;
202
203 return -EIO;
204}
205
206/*
207 * convert a disk-based directory entry to a Linux ADFS directory entry
208 */
209static inline void
210adfs_dir2obj(struct adfs_dir *dir, struct object_info *obj,
211 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 obj->filetype = -1;
220
221 /*
222 * object is a file and is filetyped and timestamped?
223 * RISC OS 12-bit filetype is stored in load_address[19:8]
224 */
225 if ((0 == (obj->attr & ADFS_NDA_DIRECTORY)) &&
226 (0xfff00000 == (0xfff00000 & obj->loadaddr))) {
227 obj->filetype = (__u16) ((0x000fff00 & obj->loadaddr) >> 8);
228
229 /* optionally append the ,xyz hex filetype suffix */
230 if (ADFS_SB(dir->sb)->s_ftsuffix)
231 obj->name_len +=
232 append_filetype_suffix(
233 &obj->name[obj->name_len],
234 obj->filetype);
235 }
236}
237
238/*
239 * convert a Linux ADFS directory entry to a disk-based directory entry
240 */
241static inline void
242adfs_obj2dir(struct adfs_direntry *de, struct object_info *obj)
243{
244 adfs_writeval(de->dirinddiscadd, 3, obj->file_id);
245 adfs_writeval(de->dirload, 4, obj->loadaddr);
246 adfs_writeval(de->direxec, 4, obj->execaddr);
247 adfs_writeval(de->dirlen, 4, obj->size);
248 de->newdiratts = obj->attr;
249}
250
251/*
252 * get a directory entry. Note that the caller is responsible
253 * for holding the relevant locks.
254 */
255static int
256__adfs_dir_get(struct adfs_dir *dir, int pos, struct object_info *obj)
257{
258 struct super_block *sb = dir->sb;
259 struct adfs_direntry de;
260 int thissize, buffer, offset;
261
262 buffer = pos >> sb->s_blocksize_bits;
263
264 if (buffer > dir->nr_buffers)
265 return -EINVAL;
266
267 offset = pos & (sb->s_blocksize - 1);
268 thissize = sb->s_blocksize - offset;
269 if (thissize > 26)
270 thissize = 26;
271
272 memcpy(&de, dir->bh[buffer]->b_data + offset, thissize);
273 if (thissize != 26)
274 memcpy(((char *)&de) + thissize, dir->bh[buffer + 1]->b_data,
275 26 - thissize);
276
277 if (!de.dirobname[0])
278 return -ENOENT;
279
280 adfs_dir2obj(dir, obj, &de);
281
282 return 0;
283}
284
285static int
286__adfs_dir_put(struct adfs_dir *dir, int pos, struct object_info *obj)
287{
288 struct super_block *sb = dir->sb;
289 struct adfs_direntry de;
290 int thissize, buffer, offset;
291
292 buffer = pos >> sb->s_blocksize_bits;
293
294 if (buffer > dir->nr_buffers)
295 return -EINVAL;
296
297 offset = pos & (sb->s_blocksize - 1);
298 thissize = sb->s_blocksize - offset;
299 if (thissize > 26)
300 thissize = 26;
301
302 /*
303 * Get the entry in total
304 */
305 memcpy(&de, dir->bh[buffer]->b_data + offset, thissize);
306 if (thissize != 26)
307 memcpy(((char *)&de) + thissize, dir->bh[buffer + 1]->b_data,
308 26 - thissize);
309
310 /*
311 * update it
312 */
313 adfs_obj2dir(&de, obj);
314
315 /*
316 * Put the new entry back
317 */
318 memcpy(dir->bh[buffer]->b_data + offset, &de, thissize);
319 if (thissize != 26)
320 memcpy(dir->bh[buffer + 1]->b_data, ((char *)&de) + thissize,
321 26 - thissize);
322
323 return 0;
324}
325
326/*
327 * the caller is responsible for holding the necessary
328 * locks.
329 */
330static int
331adfs_dir_find_entry(struct adfs_dir *dir, unsigned long object_id)
332{
333 int pos, ret;
334
335 ret = -ENOENT;
336
337 for (pos = 5; pos < ADFS_NUM_DIR_ENTRIES * 26 + 5; pos += 26) {
338 struct object_info obj;
339
340 if (!__adfs_dir_get(dir, pos, &obj))
341 break;
342
343 if (obj.file_id == object_id) {
344 ret = pos;
345 break;
346 }
347 }
348
349 return ret;
350}
351
352static int
353adfs_f_read(struct super_block *sb, unsigned int id, unsigned int sz, struct adfs_dir *dir)
354{
355 int ret;
356
357 if (sz != ADFS_NEWDIR_SIZE)
358 return -EIO;
359
360 ret = adfs_dir_read(sb, id, sz, dir);
361 if (ret)
362 adfs_error(sb, "unable to read directory");
363 else
364 dir->parent_id = adfs_readval(dir->dirtail.new.dirparent, 3);
365
366 return ret;
367}
368
369static int
370adfs_f_setpos(struct adfs_dir *dir, unsigned int fpos)
371{
372 if (fpos >= ADFS_NUM_DIR_ENTRIES)
373 return -ENOENT;
374
375 dir->pos = 5 + fpos * 26;
376 return 0;
377}
378
379static int
380adfs_f_getnext(struct adfs_dir *dir, struct object_info *obj)
381{
382 unsigned int ret;
383
384 ret = __adfs_dir_get(dir, dir->pos, obj);
385 if (ret == 0)
386 dir->pos += 26;
387
388 return ret;
389}
390
391static int
392adfs_f_update(struct adfs_dir *dir, struct object_info *obj)
393{
394 struct super_block *sb = dir->sb;
395 int ret, i;
396
397 ret = adfs_dir_find_entry(dir, obj->file_id);
398 if (ret < 0) {
399 adfs_error(dir->sb, "unable to locate entry to update");
400 goto out;
401 }
402
403 __adfs_dir_put(dir, ret, obj);
404
405 /*
406 * Increment directory sequence number
407 */
408 dir->bh[0]->b_data[0] += 1;
409 dir->bh[dir->nr_buffers - 1]->b_data[sb->s_blocksize - 6] += 1;
410
411 ret = adfs_dir_checkbyte(dir);
412 /*
413 * Update directory check byte
414 */
415 dir->bh[dir->nr_buffers - 1]->b_data[sb->s_blocksize - 1] = ret;
416
417#if 1
418 {
419 const unsigned int blocksize_bits = sb->s_blocksize_bits;
420
421 memcpy(&dir->dirhead, bufoff(dir->bh, 0), sizeof(dir->dirhead));
422 memcpy(&dir->dirtail, bufoff(dir->bh, 2007), sizeof(dir->dirtail));
423
424 if (dir->dirhead.startmasseq != dir->dirtail.new.endmasseq ||
425 memcmp(&dir->dirhead.startname, &dir->dirtail.new.endname, 4))
426 goto bad_dir;
427
428 if (memcmp(&dir->dirhead.startname, "Nick", 4) &&
429 memcmp(&dir->dirhead.startname, "Hugo", 4))
430 goto bad_dir;
431
432 if (adfs_dir_checkbyte(dir) != dir->dirtail.new.dircheckbyte)
433 goto bad_dir;
434 }
435#endif
436 for (i = dir->nr_buffers - 1; i >= 0; i--)
437 mark_buffer_dirty(dir->bh[i]);
438
439 ret = 0;
440out:
441 return ret;
442#if 1
443bad_dir:
444 adfs_error(dir->sb, "whoops! I broke a directory!");
445 return -EIO;
446#endif
447}
448
449static int
450adfs_f_sync(struct adfs_dir *dir)
451{
452 int err = 0;
453 int i;
454
455 for (i = dir->nr_buffers - 1; i >= 0; i--) {
456 struct buffer_head *bh = dir->bh[i];
457 sync_dirty_buffer(bh);
458 if (buffer_req(bh) && !buffer_uptodate(bh))
459 err = -EIO;
460 }
461
462 return err;
463}
464
465static void
466adfs_f_free(struct adfs_dir *dir)
467{
468 int i;
469
470 for (i = dir->nr_buffers - 1; i >= 0; i--) {
471 brelse(dir->bh[i]);
472 dir->bh[i] = NULL;
473 }
474
475 dir->nr_buffers = 0;
476 dir->sb = NULL;
477}
478
479const struct adfs_dir_ops adfs_f_dir_ops = {
480 .read = adfs_f_read,
481 .setpos = adfs_f_setpos,
482 .getnext = adfs_f_getnext,
483 .update = adfs_f_update,
484 .sync = adfs_f_sync,
485 .free = adfs_f_free
486};
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/adfs/dir_f.c
4 *
5 * Copyright (C) 1997-1999 Russell King
6 *
7 * E and F format directory handling
8 */
9#include "adfs.h"
10#include "dir_f.h"
11
12static void adfs_f_free(struct adfs_dir *dir);
13
14/*
15 * Read an (unaligned) value of length 1..4 bytes
16 */
17static 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;
23 /* fall through */
24 case 3: val |= p[2] << 16;
25 /* fall through */
26 case 2: val |= p[1] << 8;
27 /* fall through */
28 default: val |= p[0];
29 }
30 return val;
31}
32
33static inline void adfs_writeval(unsigned char *p, int len, unsigned int val)
34{
35 switch (len) {
36 case 4: p[3] = val >> 24;
37 /* fall through */
38 case 3: p[2] = val >> 16;
39 /* fall through */
40 case 2: p[1] = val >> 8;
41 /* fall through */
42 default: p[0] = val;
43 }
44}
45
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 */
71static u8
72adfs_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
103 do {
104 dircheck = *ptr.ptr8++ ^ ror13(dircheck);
105 } while (ptr.ptr8 < end.ptr8);
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
126/* Read and check that a directory is valid */
127static int adfs_dir_read(struct super_block *sb, u32 indaddr,
128 unsigned int size, struct adfs_dir *dir)
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
148 phys = __adfs_block_map(sb, indaddr, blk);
149 if (!phys) {
150 adfs_error(sb, "dir %06x has a hole at offset %d",
151 indaddr, blk);
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
178bad_dir:
179 adfs_error(sb, "dir %06x is corrupted", indaddr);
180release_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 */
192static inline void
193adfs_dir2obj(struct adfs_dir *dir, struct object_info *obj,
194 struct adfs_direntry *de)
195{
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;
206 obj->indaddr = adfs_readval(de->dirinddiscadd, 3);
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;
211
212 adfs_object_fixup(dir, obj);
213}
214
215/*
216 * convert a Linux ADFS directory entry to a disk-based directory entry
217 */
218static inline void
219adfs_obj2dir(struct adfs_direntry *de, struct object_info *obj)
220{
221 adfs_writeval(de->dirinddiscadd, 3, obj->indaddr);
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 */
232static 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
257 adfs_dir2obj(dir, obj, &de);
258
259 return 0;
260}
261
262static 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 */
307static int adfs_dir_find_entry(struct adfs_dir *dir, u32 indaddr)
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
319 if (obj.indaddr == indaddr) {
320 ret = pos;
321 break;
322 }
323 }
324
325 return ret;
326}
327
328static int adfs_f_read(struct super_block *sb, u32 indaddr, unsigned int size,
329 struct adfs_dir *dir)
330{
331 int ret;
332
333 if (size != ADFS_NEWDIR_SIZE)
334 return -EIO;
335
336 ret = adfs_dir_read(sb, indaddr, size, dir);
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
345static int
346adfs_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
355static int
356adfs_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
367static int
368adfs_f_update(struct adfs_dir *dir, struct object_info *obj)
369{
370 struct super_block *sb = dir->sb;
371 int ret, i;
372
373 ret = adfs_dir_find_entry(dir, obj->indaddr);
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;
416out:
417 return ret;
418#if 1
419bad_dir:
420 adfs_error(dir->sb, "whoops! I broke a directory!");
421 return -EIO;
422#endif
423}
424
425static int
426adfs_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
441static void
442adfs_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
455const struct adfs_dir_ops adfs_f_dir_ops = {
456 .read = adfs_f_read,
457 .setpos = adfs_f_setpos,
458 .getnext = adfs_f_getnext,
459 .update = adfs_f_update,
460 .sync = adfs_f_sync,
461 .free = adfs_f_free
462};