1 /*
2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
3  *
4  * Copyright (C) 2002-2011 Aleph One Ltd.
5  *   for Toby Churchill Ltd and Brightstar Engineering
6  *
7  * Created by Charles Manning <charles@aleph1.co.uk>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13 
14 #include "yaffs_verify.h"
15 #include "yaffs_trace.h"
16 #include "yaffs_bitmap.h"
17 #include "yaffs_getblockinfo.h"
18 #include "yaffs_nand.h"
19 
yaffs_skip_verification(struct yaffs_dev * dev)20 int yaffs_skip_verification(struct yaffs_dev *dev)
21 {
22 	return !(yaffs_trace_mask &
23 		 (YAFFS_TRACE_VERIFY | YAFFS_TRACE_VERIFY_FULL));
24 }
25 
yaffs_skip_full_verification(struct yaffs_dev * dev)26 static int yaffs_skip_full_verification(struct yaffs_dev *dev)
27 {
28 	return !(yaffs_trace_mask & (YAFFS_TRACE_VERIFY_FULL));
29 }
30 
yaffs_skip_nand_verification(struct yaffs_dev * dev)31 static int yaffs_skip_nand_verification(struct yaffs_dev *dev)
32 {
33 	return !(yaffs_trace_mask & (YAFFS_TRACE_VERIFY_NAND));
34 }
35 
36 static const char * const block_state_name[] = {
37 	"Unknown",
38 	"Needs scan",
39 	"Scanning",
40 	"Empty",
41 	"Allocating",
42 	"Full",
43 	"Dirty",
44 	"Checkpoint",
45 	"Collecting",
46 	"Dead"
47 };
48 
yaffs_verify_blk(struct yaffs_dev * dev,struct yaffs_block_info * bi,int n)49 void yaffs_verify_blk(struct yaffs_dev *dev, struct yaffs_block_info *bi, int n)
50 {
51 	int actually_used;
52 	int in_use;
53 
54 	if (yaffs_skip_verification(dev))
55 		return;
56 
57 	/* Report illegal runtime states */
58 	if (bi->block_state >= YAFFS_NUMBER_OF_BLOCK_STATES)
59 		yaffs_trace(YAFFS_TRACE_VERIFY,
60 			"Block %d has undefined state %d",
61 			n, bi->block_state);
62 
63 	switch (bi->block_state) {
64 	case YAFFS_BLOCK_STATE_UNKNOWN:
65 	case YAFFS_BLOCK_STATE_SCANNING:
66 	case YAFFS_BLOCK_STATE_NEEDS_SCAN:
67 		yaffs_trace(YAFFS_TRACE_VERIFY,
68 			"Block %d has bad run-state %s",
69 			n, block_state_name[bi->block_state]);
70 	}
71 
72 	/* Check pages in use and soft deletions are legal */
73 
74 	actually_used = bi->pages_in_use - bi->soft_del_pages;
75 
76 	if (bi->pages_in_use < 0 ||
77 	    bi->pages_in_use > dev->param.chunks_per_block ||
78 	    bi->soft_del_pages < 0 ||
79 	    bi->soft_del_pages > dev->param.chunks_per_block ||
80 	    actually_used < 0 || actually_used > dev->param.chunks_per_block)
81 		yaffs_trace(YAFFS_TRACE_VERIFY,
82 			"Block %d has illegal values pages_in_used %d soft_del_pages %d",
83 			n, bi->pages_in_use, bi->soft_del_pages);
84 
85 	/* Check chunk bitmap legal */
86 	in_use = yaffs_count_chunk_bits(dev, n);
87 	if (in_use != bi->pages_in_use)
88 		yaffs_trace(YAFFS_TRACE_VERIFY,
89 			"Block %d has inconsistent values pages_in_use %d counted chunk bits %d",
90 			n, bi->pages_in_use, in_use);
91 }
92 
yaffs_verify_collected_blk(struct yaffs_dev * dev,struct yaffs_block_info * bi,int n)93 void yaffs_verify_collected_blk(struct yaffs_dev *dev,
94 				struct yaffs_block_info *bi, int n)
95 {
96 	yaffs_verify_blk(dev, bi, n);
97 
98 	/* After collection the block should be in the erased state */
99 
100 	if (bi->block_state != YAFFS_BLOCK_STATE_COLLECTING &&
101 	    bi->block_state != YAFFS_BLOCK_STATE_EMPTY) {
102 		yaffs_trace(YAFFS_TRACE_ERROR,
103 			"Block %d is in state %d after gc, should be erased",
104 			n, bi->block_state);
105 	}
106 }
107 
yaffs_verify_blocks(struct yaffs_dev * dev)108 void yaffs_verify_blocks(struct yaffs_dev *dev)
109 {
110 	int i;
111 	int state_count[YAFFS_NUMBER_OF_BLOCK_STATES];
112 	int illegal_states = 0;
113 
114 	if (yaffs_skip_verification(dev))
115 		return;
116 
117 	memset(state_count, 0, sizeof(state_count));
118 
119 	for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
120 		struct yaffs_block_info *bi = yaffs_get_block_info(dev, i);
121 		yaffs_verify_blk(dev, bi, i);
122 
123 		if (bi->block_state < YAFFS_NUMBER_OF_BLOCK_STATES)
124 			state_count[bi->block_state]++;
125 		else
126 			illegal_states++;
127 	}
128 
129 	yaffs_trace(YAFFS_TRACE_VERIFY,	"Block summary");
130 
131 	yaffs_trace(YAFFS_TRACE_VERIFY,
132 		"%d blocks have illegal states",
133 		illegal_states);
134 	if (state_count[YAFFS_BLOCK_STATE_ALLOCATING] > 1)
135 		yaffs_trace(YAFFS_TRACE_VERIFY,
136 			"Too many allocating blocks");
137 
138 	for (i = 0; i < YAFFS_NUMBER_OF_BLOCK_STATES; i++)
139 		yaffs_trace(YAFFS_TRACE_VERIFY,
140 			"%s %d blocks",
141 			block_state_name[i], state_count[i]);
142 
143 	if (dev->blocks_in_checkpt != state_count[YAFFS_BLOCK_STATE_CHECKPOINT])
144 		yaffs_trace(YAFFS_TRACE_VERIFY,
145 			"Checkpoint block count wrong dev %d count %d",
146 			dev->blocks_in_checkpt,
147 			state_count[YAFFS_BLOCK_STATE_CHECKPOINT]);
148 
149 	if (dev->n_erased_blocks != state_count[YAFFS_BLOCK_STATE_EMPTY])
150 		yaffs_trace(YAFFS_TRACE_VERIFY,
151 			"Erased block count wrong dev %d count %d",
152 			dev->n_erased_blocks,
153 			state_count[YAFFS_BLOCK_STATE_EMPTY]);
154 
155 	if (state_count[YAFFS_BLOCK_STATE_COLLECTING] > 1)
156 		yaffs_trace(YAFFS_TRACE_VERIFY,
157 			"Too many collecting blocks %d (max is 1)",
158 			state_count[YAFFS_BLOCK_STATE_COLLECTING]);
159 }
160 
161 /*
162  * Verify the object header. oh must be valid, but obj and tags may be NULL in
163  * which case those tests will not be performed.
164  */
yaffs_verify_oh(struct yaffs_obj * obj,struct yaffs_obj_hdr * oh,struct yaffs_ext_tags * tags,int parent_check)165 void yaffs_verify_oh(struct yaffs_obj *obj, struct yaffs_obj_hdr *oh,
166 		     struct yaffs_ext_tags *tags, int parent_check)
167 {
168 	if (obj && yaffs_skip_verification(obj->my_dev))
169 		return;
170 
171 	if (!(tags && obj && oh)) {
172 		yaffs_trace(YAFFS_TRACE_VERIFY,
173 			"Verifying object header tags %p obj %p oh %p",
174 			tags, obj, oh);
175 		return;
176 	}
177 
178 	if (oh->type <= YAFFS_OBJECT_TYPE_UNKNOWN ||
179 	    oh->type > YAFFS_OBJECT_TYPE_MAX)
180 		yaffs_trace(YAFFS_TRACE_VERIFY,
181 			"Obj %d header type is illegal value 0x%x",
182 			tags->obj_id, oh->type);
183 
184 	if (tags->obj_id != obj->obj_id)
185 		yaffs_trace(YAFFS_TRACE_VERIFY,
186 			"Obj %d header mismatch obj_id %d",
187 			tags->obj_id, obj->obj_id);
188 
189 	/*
190 	 * Check that the object's parent ids match if parent_check requested.
191 	 *
192 	 * Tests do not apply to the root object.
193 	 */
194 
195 	if (parent_check && tags->obj_id > 1 && !obj->parent)
196 		yaffs_trace(YAFFS_TRACE_VERIFY,
197 			"Obj %d header mismatch parent_id %d obj->parent is NULL",
198 			tags->obj_id, oh->parent_obj_id);
199 
200 	if (parent_check && obj->parent &&
201 	    oh->parent_obj_id != obj->parent->obj_id &&
202 	    (oh->parent_obj_id != YAFFS_OBJECTID_UNLINKED ||
203 	     obj->parent->obj_id != YAFFS_OBJECTID_DELETED))
204 		yaffs_trace(YAFFS_TRACE_VERIFY,
205 			"Obj %d header mismatch parent_id %d parent_obj_id %d",
206 			tags->obj_id, oh->parent_obj_id,
207 			obj->parent->obj_id);
208 
209 	if (tags->obj_id > 1 && oh->name[0] == 0)	/* Null name */
210 		yaffs_trace(YAFFS_TRACE_VERIFY,
211 			"Obj %d header name is NULL",
212 			obj->obj_id);
213 
214 	if (tags->obj_id > 1 && ((u8) (oh->name[0])) == 0xff)	/* Junk name */
215 		yaffs_trace(YAFFS_TRACE_VERIFY,
216 			"Obj %d header name is 0xff",
217 			obj->obj_id);
218 }
219 
yaffs_verify_file(struct yaffs_obj * obj)220 void yaffs_verify_file(struct yaffs_obj *obj)
221 {
222 	u32 x;
223 	int required_depth;
224 	int last_chunk;
225 	u32 offset_in_chunk;
226 	u32 the_chunk;
227 
228 	u32 i;
229 	struct yaffs_dev *dev;
230 	struct yaffs_ext_tags tags;
231 	struct yaffs_tnode *tn;
232 	u32 obj_id;
233 
234 	if (!obj)
235 		return;
236 
237 	if (yaffs_skip_verification(obj->my_dev))
238 		return;
239 
240 	dev = obj->my_dev;
241 	obj_id = obj->obj_id;
242 
243 
244 	/* Check file size is consistent with tnode depth */
245 	yaffs_addr_to_chunk(dev, obj->variant.file_variant.file_size,
246 				&last_chunk, &offset_in_chunk);
247 	last_chunk++;
248 	x = last_chunk >> YAFFS_TNODES_LEVEL0_BITS;
249 	required_depth = 0;
250 	while (x > 0) {
251 		x >>= YAFFS_TNODES_INTERNAL_BITS;
252 		required_depth++;
253 	}
254 
255 	/* Check that the chunks in the tnode tree are all correct.
256 	 * We do this by scanning through the tnode tree and
257 	 * checking the tags for every chunk match.
258 	 */
259 
260 	if (yaffs_skip_nand_verification(dev))
261 		return;
262 
263 	for (i = 1; i <= last_chunk; i++) {
264 		tn = yaffs_find_tnode_0(dev, &obj->variant.file_variant, i);
265 
266 		if (!tn)
267 			continue;
268 
269 		the_chunk = yaffs_get_group_base(dev, tn, i);
270 		if (the_chunk > 0) {
271 			yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
272 						 &tags);
273 			if (tags.obj_id != obj_id || tags.chunk_id != i)
274 				yaffs_trace(YAFFS_TRACE_VERIFY,
275 					"Object %d chunk_id %d NAND mismatch chunk %d tags (%d:%d)",
276 					obj_id, i, the_chunk,
277 					tags.obj_id, tags.chunk_id);
278 		}
279 	}
280 }
281 
yaffs_verify_link(struct yaffs_obj * obj)282 void yaffs_verify_link(struct yaffs_obj *obj)
283 {
284 	if (obj && yaffs_skip_verification(obj->my_dev))
285 		return;
286 
287 	/* Verify sane equivalent object */
288 }
289 
yaffs_verify_symlink(struct yaffs_obj * obj)290 void yaffs_verify_symlink(struct yaffs_obj *obj)
291 {
292 	if (obj && yaffs_skip_verification(obj->my_dev))
293 		return;
294 
295 	/* Verify symlink string */
296 }
297 
yaffs_verify_special(struct yaffs_obj * obj)298 void yaffs_verify_special(struct yaffs_obj *obj)
299 {
300 	if (obj && yaffs_skip_verification(obj->my_dev))
301 		return;
302 }
303 
yaffs_verify_obj(struct yaffs_obj * obj)304 void yaffs_verify_obj(struct yaffs_obj *obj)
305 {
306 	struct yaffs_dev *dev;
307 	u32 chunk_min;
308 	u32 chunk_max;
309 	u32 chunk_id_ok;
310 	u32 chunk_in_range;
311 	u32 chunk_wrongly_deleted;
312 	u32 chunk_valid;
313 
314 	if (!obj)
315 		return;
316 
317 	if (obj->being_created)
318 		return;
319 
320 	dev = obj->my_dev;
321 
322 	if (yaffs_skip_verification(dev))
323 		return;
324 
325 	/* Check sane object header chunk */
326 
327 	chunk_min = dev->internal_start_block * dev->param.chunks_per_block;
328 	chunk_max =
329 	    (dev->internal_end_block + 1) * dev->param.chunks_per_block - 1;
330 
331 	chunk_in_range = (((unsigned)(obj->hdr_chunk)) >= chunk_min &&
332 			  ((unsigned)(obj->hdr_chunk)) <= chunk_max);
333 	chunk_id_ok = chunk_in_range || (obj->hdr_chunk == 0);
334 	chunk_valid = chunk_in_range &&
335 	    yaffs_check_chunk_bit(dev,
336 				  obj->hdr_chunk / dev->param.chunks_per_block,
337 				  obj->hdr_chunk % dev->param.chunks_per_block);
338 	chunk_wrongly_deleted = chunk_in_range && !chunk_valid;
339 
340 	if (!obj->fake && (!chunk_id_ok || chunk_wrongly_deleted))
341 		yaffs_trace(YAFFS_TRACE_VERIFY,
342 			"Obj %d has chunk_id %d %s %s",
343 			obj->obj_id, obj->hdr_chunk,
344 			chunk_id_ok ? "" : ",out of range",
345 			chunk_wrongly_deleted ? ",marked as deleted" : "");
346 
347 	if (chunk_valid && !yaffs_skip_nand_verification(dev)) {
348 		struct yaffs_ext_tags tags;
349 		struct yaffs_obj_hdr *oh;
350 		u8 *buffer = yaffs_get_temp_buffer(dev);
351 
352 		oh = (struct yaffs_obj_hdr *)buffer;
353 
354 		yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, buffer, &tags);
355 
356 		yaffs_verify_oh(obj, oh, &tags, 1);
357 
358 		yaffs_release_temp_buffer(dev, buffer);
359 	}
360 
361 	/* Verify it has a parent */
362 	if (obj && !obj->fake && (!obj->parent || obj->parent->my_dev != dev)) {
363 		yaffs_trace(YAFFS_TRACE_VERIFY,
364 			"Obj %d has parent pointer %p which does not look like an object",
365 			obj->obj_id, obj->parent);
366 	}
367 
368 	/* Verify parent is a directory */
369 	if (obj->parent &&
370 	    obj->parent->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
371 		yaffs_trace(YAFFS_TRACE_VERIFY,
372 			"Obj %d's parent is not a directory (type %d)",
373 			obj->obj_id, obj->parent->variant_type);
374 	}
375 
376 	switch (obj->variant_type) {
377 	case YAFFS_OBJECT_TYPE_FILE:
378 		yaffs_verify_file(obj);
379 		break;
380 	case YAFFS_OBJECT_TYPE_SYMLINK:
381 		yaffs_verify_symlink(obj);
382 		break;
383 	case YAFFS_OBJECT_TYPE_DIRECTORY:
384 		yaffs_verify_dir(obj);
385 		break;
386 	case YAFFS_OBJECT_TYPE_HARDLINK:
387 		yaffs_verify_link(obj);
388 		break;
389 	case YAFFS_OBJECT_TYPE_SPECIAL:
390 		yaffs_verify_special(obj);
391 		break;
392 	case YAFFS_OBJECT_TYPE_UNKNOWN:
393 	default:
394 		yaffs_trace(YAFFS_TRACE_VERIFY,
395 			"Obj %d has illegaltype %d",
396 		   obj->obj_id, obj->variant_type);
397 		break;
398 	}
399 }
400 
yaffs_verify_objects(struct yaffs_dev * dev)401 void yaffs_verify_objects(struct yaffs_dev *dev)
402 {
403 	struct yaffs_obj *obj;
404 	int i;
405 	struct list_head *lh;
406 
407 	if (yaffs_skip_verification(dev))
408 		return;
409 
410 	/* Iterate through the objects in each hash entry */
411 
412 	for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
413 		list_for_each(lh, &dev->obj_bucket[i].list) {
414 			obj = list_entry(lh, struct yaffs_obj, hash_link);
415 			yaffs_verify_obj(obj);
416 		}
417 	}
418 }
419 
yaffs_verify_obj_in_dir(struct yaffs_obj * obj)420 void yaffs_verify_obj_in_dir(struct yaffs_obj *obj)
421 {
422 	struct list_head *lh;
423 	struct yaffs_obj *list_obj;
424 	int count = 0;
425 
426 	if (!obj) {
427 		yaffs_trace(YAFFS_TRACE_ALWAYS, "No object to verify");
428 		BUG();
429 		return;
430 	}
431 
432 	if (yaffs_skip_verification(obj->my_dev))
433 		return;
434 
435 	if (!obj->parent) {
436 		yaffs_trace(YAFFS_TRACE_ALWAYS, "Object does not have parent");
437 		BUG();
438 		return;
439 	}
440 
441 	if (obj->parent->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
442 		yaffs_trace(YAFFS_TRACE_ALWAYS, "Parent is not directory");
443 		BUG();
444 	}
445 
446 	/* Iterate through the objects in each hash entry */
447 
448 	list_for_each(lh, &obj->parent->variant.dir_variant.children) {
449 		list_obj = list_entry(lh, struct yaffs_obj, siblings);
450 		yaffs_verify_obj(list_obj);
451 		if (obj == list_obj)
452 			count++;
453 	}
454 
455 	if (count != 1) {
456 		yaffs_trace(YAFFS_TRACE_ALWAYS,
457 			"Object in directory %d times",
458 			count);
459 		BUG();
460 	}
461 }
462 
yaffs_verify_dir(struct yaffs_obj * directory)463 void yaffs_verify_dir(struct yaffs_obj *directory)
464 {
465 	struct list_head *lh;
466 	struct yaffs_obj *list_obj;
467 
468 	if (!directory) {
469 		BUG();
470 		return;
471 	}
472 
473 	if (yaffs_skip_full_verification(directory->my_dev))
474 		return;
475 
476 	if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
477 		yaffs_trace(YAFFS_TRACE_ALWAYS,
478 			"Directory has wrong type: %d",
479 			directory->variant_type);
480 		BUG();
481 	}
482 
483 	/* Iterate through the objects in each hash entry */
484 
485 	list_for_each(lh, &directory->variant.dir_variant.children) {
486 		list_obj = list_entry(lh, struct yaffs_obj, siblings);
487 		if (list_obj->parent != directory) {
488 			yaffs_trace(YAFFS_TRACE_ALWAYS,
489 				"Object in directory list has wrong parent %p",
490 				list_obj->parent);
491 			BUG();
492 		}
493 		yaffs_verify_obj_in_dir(list_obj);
494 	}
495 }
496 
497 static int yaffs_free_verification_failures;
498 
yaffs_verify_free_chunks(struct yaffs_dev * dev)499 void yaffs_verify_free_chunks(struct yaffs_dev *dev)
500 {
501 	int counted;
502 	int difference;
503 
504 	if (yaffs_skip_verification(dev))
505 		return;
506 
507 	counted = yaffs_count_free_chunks(dev);
508 
509 	difference = dev->n_free_chunks - counted;
510 
511 	if (difference) {
512 		yaffs_trace(YAFFS_TRACE_ALWAYS,
513 			"Freechunks verification failure %d %d %d",
514 			dev->n_free_chunks, counted, difference);
515 		yaffs_free_verification_failures++;
516 	}
517 }
518 
yaffs_verify_file_sane(struct yaffs_obj * in)519 int yaffs_verify_file_sane(struct yaffs_obj *in)
520 {
521 	return YAFFS_OK;
522 }
523