drivers/md/bcache/debug.c

   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 }