aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/md/bcache/debug.c
blob: 264fcfbd629016aa1ab890cce56de2699c49be70 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
/*
 * Assorted bcache debug code
 *
 * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
 * Copyright 2012 Google, Inc.
 */

#include "bcache.h"
#include "btree.h"
#include "debug.h"

#include <linux/console.h>
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/seq_file.h>

static struct dentry *debug;

const char *bch_ptr_status(struct cache_set *c, const struct bkey *k)
{
	unsigned i;

	for (i = 0; i < KEY_PTRS(k); i++)
		if (ptr_available(c, k, i)) {
			struct cache *ca = PTR_CACHE(c, k, i);
			size_t bucket = PTR_BUCKET_NR(c, k, i);
			size_t r = bucket_remainder(c, PTR_OFFSET(k, i));

			if (KEY_SIZE(k) + r > c->sb.bucket_size)
				return "bad, length too big";
			if (bucket <  ca->sb.first_bucket)
				return "bad, short offset";
			if (bucket >= ca->sb.nbuckets)
				return "bad, offset past end of device";
			if (ptr_stale(c, k, i))
				return "stale";
		}

	if (!bkey_cmp(k, &ZERO_KEY))
		return "bad, null key";
	if (!KEY_PTRS(k))
		return "bad, no pointers";
	if (!KEY_SIZE(k))
		return "zeroed key";
	return "";
}

int bch_bkey_to_text(char *buf, size_t size, const struct bkey *k)
{
	unsigned i = 0;
	char *out = buf, *end = buf + size;

#define p(...)	(out += scnprintf(out, end - out, __VA_ARGS__))

	p("%llu:%llu len %llu -> [", KEY_INODE(k), KEY_OFFSET(k), KEY_SIZE(k));

	if (KEY_PTRS(k))
		while (1) {
			p("%llu:%llu gen %llu",
			  PTR_DEV(k, i), PTR_OFFSET(k, i), PTR_GEN(k, i));

			if (++i == KEY_PTRS(k))
				break;

			p(", ");
		}

	p("]");

	if (KEY_DIRTY(k))
		p(" dirty");
	if (KEY_CSUM(k))
		p(" cs%llu %llx", KEY_CSUM(k), k->ptr[1]);
#undef p
	return out - buf;
}

#ifdef CONFIG_BCACHE_DEBUG

static void dump_bset(struct btree *b, struct bset *i)
{
	struct bkey *k, *next;
	unsigned j;
	char buf[80];

	for (k = i->start; k < end(i); k = next) {
		next = bkey_next(k);

		bch_bkey_to_text(buf, sizeof(buf), k);
		printk(KERN_ERR "block %zu key %zi/%u: %s", index(i, b),
		       (uint64_t *) k - i->d, i->keys, buf);

		for (j = 0; j < KEY_PTRS(k); j++) {
			size_t n = PTR_BUCKET_NR(b->c, k, j);
			printk(" bucket %zu", n);

			if (n >= b->c->sb.first_bucket && n < b->c->sb.nbuckets)
				printk(" prio %i",
				       PTR_BUCKET(b->c, k, j)->prio);
		}

		printk(" %s\n", bch_ptr_status(b->c, k));

		if (next < end(i) &&
		    bkey_cmp(k, !b->level ? &START_KEY(next) : next) > 0)
			printk(KERN_ERR "Key skipped backwards\n");
	}
}

static void bch_dump_bucket(struct btree *b)
{
	unsigned i;

	console_lock();
	for (i = 0; i <= b->nsets; i++)
		dump_bset(b, b->sets[i].data);
	console_unlock();
}

void bch_btree_verify(struct btree *b, struct bset *new)
{
	struct btree *v = b->c->verify_data;
	struct closure cl;
	closure_init_stack(&cl);

	if (!b->c->verify)
		return;

	closure_wait_event(&b->io.wait, &cl,
			   atomic_read(&b->io.cl.remaining) == -1);

	mutex_lock(&b->c->verify_lock);

	bkey_copy(&v->key, &b->key);
	v->written = 0;
	v->level = b->level;

	bch_btree_node_read(v);
	closure_wait_event(&v->io.wait, &cl,
			   atomic_read(&b->io.cl.remaining) == -1);

	if (new->keys != v->sets[0].data->keys ||
	    memcmp(new->start,
		   v->sets[0].data->start,
		   (void *) end(new) - (void *) new->start)) {
		unsigned i, j;

		console_lock();

		printk(KERN_ERR "*** original memory node:\n");
		for (i = 0; i <= b->nsets; i++)
			dump_bset(b, b->sets[i].data);

		printk(KERN_ERR "*** sorted memory node:\n");
		dump_bset(b, new);

		printk(KERN_ERR "*** on disk node:\n");
		dump_bset(v, v->sets[0].data);

		for (j = 0; j < new->keys; j++)
			if (new->d[j] != v->sets[0].data->d[j])
				break;

		console_unlock();
		panic("verify failed at %u\n", j);
	}

	mutex_unlock(&b->c->verify_lock);
}

void bch_data_verify(struct cached_dev *dc, struct bio *bio)
{
	char name[BDEVNAME_SIZE];
	struct bio *check;
	struct bio_vec *bv;
	int i;

	check = bio_clone(bio, GFP_NOIO);
	if (!check)
		return;

	if (bio_alloc_pages(check, GFP_NOIO))
		goto out_put;

	submit_bio_wait(READ_SYNC, check);

	bio_for_each_segment(bv, bio, i) {
		void *p1 = kmap_atomic(bv->bv_page);
		void *p2 = page_address(check->bi_io_vec[i].bv_page);

		cache_set_err_on(memcmp(p1 + bv->bv_offset,
					p2 + bv->bv_offset,
					bv->bv_len),
				 dc->disk.c,
				 "verify failed at dev %s sector %llu",
				 bdevname(dc->bdev, name),
				 (uint64_t) bio->bi_sector);

		kunmap_atomic(p1);
	}

	bio_for_each_segment_all(bv, check, i)
		__free_page(bv->bv_page);
out_put:
	bio_put(check);
}

int __bch_count_data(struct btree *b)
{
	unsigned ret = 0;
	struct btree_iter iter;
	struct bkey *k;

	if (!b->level)
		for_each_key(b, k, &iter)
			ret += KEY_SIZE(k);
	return ret;
}

void __bch_check_keys(struct btree *b, const char *fmt, ...)
{
	va_list args;
	struct bkey *k, *p = NULL;
	struct btree_iter iter;
	const char *err;

	for_each_key(b, k, &iter) {
		if (!b->level) {
			err = "Keys out of order";
			if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0)
				goto bug;

			if (bch_ptr_invalid(b, k))
				continue;

			err =  "Overlapping keys";
			if (p && bkey_cmp(p, &START_KEY(k)) > 0)
				goto bug;
		} else {
			if (bch_ptr_bad(b, k))
				continue;

			err = "Duplicate keys";
			if (p && !bkey_cmp(p, k))
				goto bug;
		}
		p = k;
	}

	err = "Key larger than btree node key";
	if (p && bkey_cmp(p, &b->key) > 0)
		goto bug;

	return;
bug:
	bch_dump_bucket(b);

	va_start(args, fmt);
	vprintk(fmt, args);
	va_end(args);

	panic("bcache error: %s:\n", err);
}

void bch_btree_iter_next_check(struct btree_iter *iter)
{
	struct bkey *k = iter->data->k, *next = bkey_next(k);

	if (next < iter->data->end &&
	    bkey_cmp(k, iter->b->level ? next : &START_KEY(next)) > 0) {
		bch_dump_bucket(iter->b);
		panic("Key skipped backwards\n");
	}
}

#endif

#ifdef CONFIG_DEBUG_FS

/* XXX: cache set refcounting */

struct dump_iterator {
	char			buf[PAGE_SIZE];
	size_t			bytes;
	struct cache_set	*c;
	struct keybuf		keys;
};

static bool dump_pred(struct keybuf *buf, struct bkey *k)
{
	return true;
}

static ssize_t bch_dump_read(struct file *file, char __user *buf,
			     size_t size, loff_t *ppos)
{
	struct dump_iterator *i = file->private_data;
	ssize_t ret = 0;
	char kbuf[80];

	while (size) {
		struct keybuf_key *w;
		unsigned bytes = min(i->bytes, size);

		int err = copy_to_user(buf, i->buf, bytes);
		if (err)
			return err;

		ret	 += bytes;
		buf	 += bytes;
		size	 -= bytes;
		i->bytes -= bytes;
		memmove(i->buf, i->buf + bytes, i->bytes);

		if (i->bytes)
			break;

		w = bch_keybuf_next_rescan(i->c, &i->keys, &MAX_KEY, dump_pred);
		if (!w)
			break;

		bch_bkey_to_text(kbuf, sizeof(kbuf), &w->key);
		i->bytes = snprintf(i->buf, PAGE_SIZE, "%s\n", kbuf);
		bch_keybuf_del(&i->keys, w);
	}

	return ret;
}

static int bch_dump_open(struct inode *inode, struct file *file)
{
	struct cache_set *c = inode->i_private;
	struct dump_iterator *i;

	i = kzalloc(sizeof(struct dump_iterator), GFP_KERNEL);
	if (!i)
		return -ENOMEM;

	file->private_data = i;
	i->c = c;
	bch_keybuf_init(&i->keys);
	i->keys.last_scanned = KEY(0, 0, 0);

	return 0;
}

static int bch_dump_release(struct inode *inode, struct file *file)
{
	kfree(file->private_data);
	return 0;
}

static const struct file_operations cache_set_debug_ops = {
	.owner		= THIS_MODULE,
	.open		= bch_dump_open,
	.read		= bch_dump_read,
	.release	= bch_dump_release
};

void bch_debug_init_cache_set(struct cache_set *c)
{
	if (!IS_ERR_OR_NULL(debug)) {
		char name[50];
		snprintf(name, 50, "bcache-%pU", c->sb.set_uuid);

		c->debug = debugfs_create_file(name, 0400, debug, c,
					       &cache_set_debug_ops);
	}
}

#endif

void bch_debug_exit(void)
{
	if (!IS_ERR_OR_NULL(debug))
		debugfs_remove_recursive(debug);
}

int __init bch_debug_init(struct kobject *kobj)
{
	int ret = 0;

	debug = debugfs_create_dir("bcache", NULL);
	return ret;
}