xref: /openbmc/linux/drivers/md/bcache/debug.c (revision ee89bd6b) 
1 /*
2  * Assorted bcache debug code
3  *
4  * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
5  * Copyright 2012 Google, Inc.
6  */
7 
8 #include "bcache.h"
9 #include "btree.h"
10 #include "debug.h"
11 #include "request.h"
12 
13 #include <linux/console.h>
14 #include <linux/debugfs.h>
15 #include <linux/module.h>
16 #include <linux/random.h>
17 #include <linux/seq_file.h>
18 
19 static struct dentry *debug;
20 
21 const char *bch_ptr_status(struct cache_set *c, const struct bkey *k)
22 {
23 	unsigned i;
24 
25 	for (i = 0; i < KEY_PTRS(k); i++)
26 		if (ptr_available(c, k, i)) {
27 			struct cache *ca = PTR_CACHE(c, k, i);
28 			size_t bucket = PTR_BUCKET_NR(c, k, i);
29 			size_t r = bucket_remainder(c, PTR_OFFSET(k, i));
30 
31 			if (KEY_SIZE(k) + r > c->sb.bucket_size)
32 				return "bad, length too big";
33 			if (bucket <  ca->sb.first_bucket)
34 				return "bad, short offset";
35 			if (bucket >= ca->sb.nbuckets)
36 				return "bad, offset past end of device";
37 			if (ptr_stale(c, k, i))
38 				return "stale";
39 		}
40 
41 	if (!bkey_cmp(k, &ZERO_KEY))
42 		return "bad, null key";
43 	if (!KEY_PTRS(k))
44 		return "bad, no pointers";
45 	if (!KEY_SIZE(k))
46 		return "zeroed key";
47 	return "";
48 }
49 
50 struct keyprint_hack bch_pkey(const struct bkey *k)
51 {
52 	unsigned i = 0;
53 	struct keyprint_hack r;
54 	char *out = r.s, *end = r.s + KEYHACK_SIZE;
55 
56 #define p(...)	(out += scnprintf(out, end - out, __VA_ARGS__))
57 
58 	p("%llu:%llu len %llu -> [", KEY_INODE(k), KEY_OFFSET(k), KEY_SIZE(k));
59 
60 	if (KEY_PTRS(k))
61 		while (1) {
62 			p("%llu:%llu gen %llu",
63 			  PTR_DEV(k, i), PTR_OFFSET(k, i), PTR_GEN(k, i));
64 
65 			if (++i == KEY_PTRS(k))
66 				break;
67 
68 			p(", ");
69 		}
70 
71 	p("]");
72 
73 	if (KEY_DIRTY(k))
74 		p(" dirty");
75 	if (KEY_CSUM(k))
76 		p(" cs%llu %llx", KEY_CSUM(k), k->ptr[1]);
77 #undef p
78 	return r;
79 }
80 
81 struct keyprint_hack bch_pbtree(const struct btree *b)
82 {
83 	struct keyprint_hack r;
84 
85 	snprintf(r.s, 40, "%zu level %i/%i", PTR_BUCKET_NR(b->c, &b->key, 0),
86 		 b->level, b->c->root ? b->c->root->level : -1);
87 	return r;
88 }
89 
90 #if defined(CONFIG_BCACHE_DEBUG) || defined(CONFIG_BCACHE_EDEBUG)
91 
92 static bool skipped_backwards(struct btree *b, struct bkey *k)
93 {
94 	return bkey_cmp(k, (!b->level)
95 			? &START_KEY(bkey_next(k))
96 			: bkey_next(k)) > 0;
97 }
98 
99 static void dump_bset(struct btree *b, struct bset *i)
100 {
101 	struct bkey *k;
102 	unsigned j;
103 
104 	for (k = i->start; k < end(i); k = bkey_next(k)) {
105 		printk(KERN_ERR "block %zu key %zi/%u: %s", index(i, b),
106 		       (uint64_t *) k - i->d, i->keys, pkey(k));
107 
108 		for (j = 0; j < KEY_PTRS(k); j++) {
109 			size_t n = PTR_BUCKET_NR(b->c, k, j);
110 			printk(" bucket %zu", n);
111 
112 			if (n >= b->c->sb.first_bucket && n < b->c->sb.nbuckets)
113 				printk(" prio %i",
114 				       PTR_BUCKET(b->c, k, j)->prio);
115 		}
116 
117 		printk(" %s\n", bch_ptr_status(b->c, k));
118 
119 		if (bkey_next(k) < end(i) &&
120 		    skipped_backwards(b, k))
121 			printk(KERN_ERR "Key skipped backwards\n");
122 	}
123 }
124 
125 #endif
126 
127 #ifdef CONFIG_BCACHE_DEBUG
128 
129 void bch_btree_verify(struct btree *b, struct bset *new)
130 {
131 	struct btree *v = b->c->verify_data;
132 	struct closure cl;
133 	closure_init_stack(&cl);
134 
135 	if (!b->c->verify)
136 		return;
137 
138 	closure_wait_event(&b->io.wait, &cl,
139 			   atomic_read(&b->io.cl.remaining) == -1);
140 
141 	mutex_lock(&b->c->verify_lock);
142 
143 	bkey_copy(&v->key, &b->key);
144 	v->written = 0;
145 	v->level = b->level;
146 
147 	bch_btree_read(v);
148 	closure_wait_event(&v->io.wait, &cl,
149 			   atomic_read(&b->io.cl.remaining) == -1);
150 
151 	if (new->keys != v->sets[0].data->keys ||
152 	    memcmp(new->start,
153 		   v->sets[0].data->start,
154 		   (void *) end(new) - (void *) new->start)) {
155 		unsigned i, j;
156 
157 		console_lock();
158 
159 		printk(KERN_ERR "*** original memory node:\n");
160 		for (i = 0; i <= b->nsets; i++)
161 			dump_bset(b, b->sets[i].data);
162 
163 		printk(KERN_ERR "*** sorted memory node:\n");
164 		dump_bset(b, new);
165 
166 		printk(KERN_ERR "*** on disk node:\n");
167 		dump_bset(v, v->sets[0].data);
168 
169 		for (j = 0; j < new->keys; j++)
170 			if (new->d[j] != v->sets[0].data->d[j])
171 				break;
172 
173 		console_unlock();
174 		panic("verify failed at %u\n", j);
175 	}
176 
177 	mutex_unlock(&b->c->verify_lock);
178 }
179 
180 static void data_verify_endio(struct bio *bio, int error)
181 {
182 	struct closure *cl = bio->bi_private;
183 	closure_put(cl);
184 }
185 
186 void bch_data_verify(struct search *s)
187 {
188 	char name[BDEVNAME_SIZE];
189 	struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
190 	struct closure *cl = &s->cl;
191 	struct bio *check;
192 	struct bio_vec *bv;
193 	int i;
194 
195 	if (!s->unaligned_bvec)
196 		bio_for_each_segment(bv, s->orig_bio, i)
197 			bv->bv_offset = 0, bv->bv_len = PAGE_SIZE;
198 
199 	check = bio_clone(s->orig_bio, GFP_NOIO);
200 	if (!check)
201 		return;
202 
203 	if (bch_bio_alloc_pages(check, GFP_NOIO))
204 		goto out_put;
205 
206 	check->bi_rw		= READ_SYNC;
207 	check->bi_private	= cl;
208 	check->bi_end_io	= data_verify_endio;
209 
210 	closure_bio_submit(check, cl, &dc->disk);
211 	closure_sync(cl);
212 
213 	bio_for_each_segment(bv, s->orig_bio, i) {
214 		void *p1 = kmap(bv->bv_page);
215 		void *p2 = kmap(check->bi_io_vec[i].bv_page);
216 
217 		if (memcmp(p1 + bv->bv_offset,
218 			   p2 + bv->bv_offset,
219 			   bv->bv_len))
220 			printk(KERN_ERR
221 			       "bcache (%s): verify failed at sector %llu\n",
222 			       bdevname(dc->bdev, name),
223 			       (uint64_t) s->orig_bio->bi_sector);
224 
225 		kunmap(bv->bv_page);
226 		kunmap(check->bi_io_vec[i].bv_page);
227 	}
228 
229 	__bio_for_each_segment(bv, check, i, 0)
230 		__free_page(bv->bv_page);
231 out_put:
232 	bio_put(check);
233 }
234 
235 #endif
236 
237 #ifdef CONFIG_BCACHE_EDEBUG
238 
239 unsigned bch_count_data(struct btree *b)
240 {
241 	unsigned ret = 0;
242 	struct btree_iter iter;
243 	struct bkey *k;
244 
245 	if (!b->level)
246 		for_each_key(b, k, &iter)
247 			ret += KEY_SIZE(k);
248 	return ret;
249 }
250 
251 static void vdump_bucket_and_panic(struct btree *b, const char *fmt,
252 				   va_list args)
253 {
254 	unsigned i;
255 
256 	console_lock();
257 
258 	for (i = 0; i <= b->nsets; i++)
259 		dump_bset(b, b->sets[i].data);
260 
261 	vprintk(fmt, args);
262 
263 	console_unlock();
264 
265 	panic("at %s\n", pbtree(b));
266 }
267 
268 void bch_check_key_order_msg(struct btree *b, struct bset *i,
269 			     const char *fmt, ...)
270 {
271 	struct bkey *k;
272 
273 	if (!i->keys)
274 		return;
275 
276 	for (k = i->start; bkey_next(k) < end(i); k = bkey_next(k))
277 		if (skipped_backwards(b, k)) {
278 			va_list args;
279 			va_start(args, fmt);
280 
281 			vdump_bucket_and_panic(b, fmt, args);
282 			va_end(args);
283 		}
284 }
285 
286 void bch_check_keys(struct btree *b, const char *fmt, ...)
287 {
288 	va_list args;
289 	struct bkey *k, *p = NULL;
290 	struct btree_iter iter;
291 
292 	if (b->level)
293 		return;
294 
295 	for_each_key(b, k, &iter) {
296 		if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0) {
297 			printk(KERN_ERR "Keys out of order:\n");
298 			goto bug;
299 		}
300 
301 		if (bch_ptr_invalid(b, k))
302 			continue;
303 
304 		if (p && bkey_cmp(p, &START_KEY(k)) > 0) {
305 			printk(KERN_ERR "Overlapping keys:\n");
306 			goto bug;
307 		}
308 		p = k;
309 	}
310 	return;
311 bug:
312 	va_start(args, fmt);
313 	vdump_bucket_and_panic(b, fmt, args);
314 	va_end(args);
315 }
316 
317 #endif
318 
319 #ifdef CONFIG_DEBUG_FS
320 
321 /* XXX: cache set refcounting */
322 
323 struct dump_iterator {
324 	char			buf[PAGE_SIZE];
325 	size_t			bytes;
326 	struct cache_set	*c;
327 	struct keybuf		keys;
328 };
329 
330 static bool dump_pred(struct keybuf *buf, struct bkey *k)
331 {
332 	return true;
333 }
334 
335 static ssize_t bch_dump_read(struct file *file, char __user *buf,
336 			     size_t size, loff_t *ppos)
337 {
338 	struct dump_iterator *i = file->private_data;
339 	ssize_t ret = 0;
340 
341 	while (size) {
342 		struct keybuf_key *w;
343 		unsigned bytes = min(i->bytes, size);
344 
345 		int err = copy_to_user(buf, i->buf, bytes);
346 		if (err)
347 			return err;
348 
349 		ret	 += bytes;
350 		buf	 += bytes;
351 		size	 -= bytes;
352 		i->bytes -= bytes;
353 		memmove(i->buf, i->buf + bytes, i->bytes);
354 
355 		if (i->bytes)
356 			break;
357 
358 		w = bch_keybuf_next_rescan(i->c, &i->keys, &MAX_KEY);
359 		if (!w)
360 			break;
361 
362 		i->bytes = snprintf(i->buf, PAGE_SIZE, "%s\n", pkey(&w->key));
363 		bch_keybuf_del(&i->keys, w);
364 	}
365 
366 	return ret;
367 }
368 
369 static int bch_dump_open(struct inode *inode, struct file *file)
370 {
371 	struct cache_set *c = inode->i_private;
372 	struct dump_iterator *i;
373 
374 	i = kzalloc(sizeof(struct dump_iterator), GFP_KERNEL);
375 	if (!i)
376 		return -ENOMEM;
377 
378 	file->private_data = i;
379 	i->c = c;
380 	bch_keybuf_init(&i->keys, dump_pred);
381 	i->keys.last_scanned = KEY(0, 0, 0);
382 
383 	return 0;
384 }
385 
386 static int bch_dump_release(struct inode *inode, struct file *file)
387 {
388 	kfree(file->private_data);
389 	return 0;
390 }
391 
392 static const struct file_operations cache_set_debug_ops = {
393 	.owner		= THIS_MODULE,
394 	.open		= bch_dump_open,
395 	.read		= bch_dump_read,
396 	.release	= bch_dump_release
397 };
398 
399 void bch_debug_init_cache_set(struct cache_set *c)
400 {
401 	if (!IS_ERR_OR_NULL(debug)) {
402 		char name[50];
403 		snprintf(name, 50, "bcache-%pU", c->sb.set_uuid);
404 
405 		c->debug = debugfs_create_file(name, 0400, debug, c,
406 					       &cache_set_debug_ops);
407 	}
408 }
409 
410 #endif
411 
412 /* Fuzz tester has rotted: */
413 #if 0
414 
415 static ssize_t btree_fuzz(struct kobject *k, struct kobj_attribute *a,
416 			  const char *buffer, size_t size)
417 {
418 	void dump(struct btree *b)
419 	{
420 		struct bset *i;
421 
422 		for (i = b->sets[0].data;
423 		     index(i, b) < btree_blocks(b) &&
424 		     i->seq == b->sets[0].data->seq;
425 		     i = ((void *) i) + set_blocks(i, b->c) * block_bytes(b->c))
426 			dump_bset(b, i);
427 	}
428 
429 	struct cache_sb *sb;
430 	struct cache_set *c;
431 	struct btree *all[3], *b, *fill, *orig;
432 	int j;
433 
434 	struct btree_op op;
435 	bch_btree_op_init_stack(&op);
436 
437 	sb = kzalloc(sizeof(struct cache_sb), GFP_KERNEL);
438 	if (!sb)
439 		return -ENOMEM;
440 
441 	sb->bucket_size = 128;
442 	sb->block_size = 4;
443 
444 	c = bch_cache_set_alloc(sb);
445 	if (!c)
446 		return -ENOMEM;
447 
448 	for (j = 0; j < 3; j++) {
449 		BUG_ON(list_empty(&c->btree_cache));
450 		all[j] = list_first_entry(&c->btree_cache, struct btree, list);
451 		list_del_init(&all[j]->list);
452 
453 		all[j]->key = KEY(0, 0, c->sb.bucket_size);
454 		bkey_copy_key(&all[j]->key, &MAX_KEY);
455 	}
456 
457 	b = all[0];
458 	fill = all[1];
459 	orig = all[2];
460 
461 	while (1) {
462 		for (j = 0; j < 3; j++)
463 			all[j]->written = all[j]->nsets = 0;
464 
465 		bch_bset_init_next(b);
466 
467 		while (1) {
468 			struct bset *i = write_block(b);
469 			struct bkey *k = op.keys.top;
470 			unsigned rand;
471 
472 			bkey_init(k);
473 			rand = get_random_int();
474 
475 			op.type = rand & 1
476 				? BTREE_INSERT
477 				: BTREE_REPLACE;
478 			rand >>= 1;
479 
480 			SET_KEY_SIZE(k, bucket_remainder(c, rand));
481 			rand >>= c->bucket_bits;
482 			rand &= 1024 * 512 - 1;
483 			rand += c->sb.bucket_size;
484 			SET_KEY_OFFSET(k, rand);
485 #if 0
486 			SET_KEY_PTRS(k, 1);
487 #endif
488 			bch_keylist_push(&op.keys);
489 			bch_btree_insert_keys(b, &op);
490 
491 			if (should_split(b) ||
492 			    set_blocks(i, b->c) !=
493 			    __set_blocks(i, i->keys + 15, b->c)) {
494 				i->csum = csum_set(i);
495 
496 				memcpy(write_block(fill),
497 				       i, set_bytes(i));
498 
499 				b->written += set_blocks(i, b->c);
500 				fill->written = b->written;
501 				if (b->written == btree_blocks(b))
502 					break;
503 
504 				bch_btree_sort_lazy(b);
505 				bch_bset_init_next(b);
506 			}
507 		}
508 
509 		memcpy(orig->sets[0].data,
510 		       fill->sets[0].data,
511 		       btree_bytes(c));
512 
513 		bch_btree_sort(b);
514 		fill->written = 0;
515 		bch_btree_read_done(&fill->io.cl);
516 
517 		if (b->sets[0].data->keys != fill->sets[0].data->keys ||
518 		    memcmp(b->sets[0].data->start,
519 			   fill->sets[0].data->start,
520 			   b->sets[0].data->keys * sizeof(uint64_t))) {
521 			struct bset *i = b->sets[0].data;
522 			struct bkey *k, *l;
523 
524 			for (k = i->start,
525 			     l = fill->sets[0].data->start;
526 			     k < end(i);
527 			     k = bkey_next(k), l = bkey_next(l))
528 				if (bkey_cmp(k, l) ||
529 				    KEY_SIZE(k) != KEY_SIZE(l))
530 					pr_err("key %zi differs: %s != %s",
531 					       (uint64_t *) k - i->d,
532 					       pkey(k), pkey(l));
533 
534 			for (j = 0; j < 3; j++) {
535 				pr_err("**** Set %i ****", j);
536 				dump(all[j]);
537 			}
538 			panic("\n");
539 		}
540 
541 		pr_info("fuzz complete: %i keys", b->sets[0].data->keys);
542 	}
543 }
544 
545 kobj_attribute_write(fuzz, btree_fuzz);
546 #endif
547 
548 void bch_debug_exit(void)
549 {
550 	if (!IS_ERR_OR_NULL(debug))
551 		debugfs_remove_recursive(debug);
552 }
553 
554 int __init bch_debug_init(struct kobject *kobj)
555 {
556 	int ret = 0;
557 #if 0
558 	ret = sysfs_create_file(kobj, &ksysfs_fuzz.attr);
559 	if (ret)
560 		return ret;
561 #endif
562 
563 	debug = debugfs_create_dir("bcache", NULL);
564 	return ret;
565 }
566