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 int bch_bkey_to_text(char *buf, size_t size, const struct bkey *k)
  51 {
  52         unsigned i = 0;
  53         char *out = buf, *end = buf + size;
  54
  55 #define p(...)  (out += scnprintf(out, end - out, __VA_ARGS__))
  56
  57         p("%llu:%llu len %llu -> [", KEY_INODE(k), KEY_OFFSET(k), KEY_SIZE(k));
  58
  59         if (KEY_PTRS(k))
  60                 while (1) {
  61                         p("%llu:%llu gen %llu",
  62                           PTR_DEV(k, i), PTR_OFFSET(k, i), PTR_GEN(k, i));
  63
  64                         if (++i == KEY_PTRS(k))
  65                                 break;
  66
  67                         p(", ");
  68                 }
  69
  70         p("]");
  71
  72         if (KEY_DIRTY(k))
  73                 p(" dirty");
  74         if (KEY_CSUM(k))
  75                 p(" cs%llu %llx", KEY_CSUM(k), k->ptr[1]);
  76 #undef p
  77         return out - buf;
  78 }
  79
  80 int bch_btree_to_text(char *buf, size_t size, const struct btree *b)
  81 {
  82         return scnprintf(buf, size, "%zu level %i/%i",
  83                          PTR_BUCKET_NR(b->c, &b->key, 0),
  84                          b->level, b->c->root ? b->c->root->level : -1);
  85 }
  86
  87 #if defined(CONFIG_BCACHE_DEBUG) || defined(CONFIG_BCACHE_EDEBUG)
  88
  89 static bool skipped_backwards(struct btree *b, struct bkey *k)
  90 {
  91         return bkey_cmp(k, (!b->level)
  92                         ? &START_KEY(bkey_next(k))
  93                         : bkey_next(k)) > 0;
  94 }
  95
  96 static void dump_bset(struct btree *b, struct bset *i)
  97 {
  98         struct bkey *k;
  99         unsigned j;
 100         char buf[80];
 101
 102         for (k = i->start; k < end(i); k = bkey_next(k)) {
 103                 bch_bkey_to_text(buf, sizeof(buf), k);
 104                 printk(KERN_ERR "block %zu key %zi/%u: %s", index(i, b),
 105                        (uint64_t *) k - i->d, i->keys, buf);
 106
 107                 for (j = 0; j < KEY_PTRS(k); j++) {
 108                         size_t n = PTR_BUCKET_NR(b->c, k, j);
 109                         printk(" bucket %zu", n);
 110
 111                         if (n >= b->c->sb.first_bucket && n < b->c->sb.nbuckets)
 112                                 printk(" prio %i",
 113                                        PTR_BUCKET(b->c, k, j)->prio);
 114                 }
 115
 116                 printk(" %s\n", bch_ptr_status(b->c, k));
 117
 118                 if (bkey_next(k) < end(i) &&
 119                     skipped_backwards(b, k))
 120                         printk(KERN_ERR "Key skipped backwards\n");
 121         }
 122 }
 123
 124 #endif
 125
 126 #ifdef CONFIG_BCACHE_DEBUG
 127
 128 void bch_btree_verify(struct btree *b, struct bset *new)
 129 {
 130         struct btree *v = b->c->verify_data;
 131         struct closure cl;
 132         closure_init_stack(&cl);
 133
 134         if (!b->c->verify)
 135                 return;
 136
 137         closure_wait_event(&b->io.wait, &cl,
 138                            atomic_read(&b->io.cl.remaining) == -1);
 139
 140         mutex_lock(&b->c->verify_lock);
 141
 142         bkey_copy(&v->key, &b->key);
 143         v->written = 0;
 144         v->level = b->level;
 145
 146         bch_btree_node_read(v);
 147         closure_wait_event(&v->io.wait, &cl,
 148                            atomic_read(&b->io.cl.remaining) == -1);
 149
 150         if (new->keys != v->sets[0].data->keys ||
 151             memcmp(new->start,
 152                    v->sets[0].data->start,
 153                    (void *) end(new) - (void *) new->start)) {
 154                 unsigned i, j;
 155
 156                 console_lock();
 157
 158                 printk(KERN_ERR "*** original memory node:\n");
 159                 for (i = 0; i <= b->nsets; i++)
 160                         dump_bset(b, b->sets[i].data);
 161
 162                 printk(KERN_ERR "*** sorted memory node:\n");
 163                 dump_bset(b, new);
 164
 165                 printk(KERN_ERR "*** on disk node:\n");
 166                 dump_bset(v, v->sets[0].data);
 167
 168                 for (j = 0; j < new->keys; j++)
 169                         if (new->d[j] != v->sets[0].data->d[j])
 170                                 break;
 171
 172                 console_unlock();
 173                 panic("verify failed at %u\n", j);
 174         }
 175
 176         mutex_unlock(&b->c->verify_lock);
 177 }
 178
 179 static void data_verify_endio(struct bio *bio, int error)
 180 {
 181         struct closure *cl = bio->bi_private;
 182         closure_put(cl);
 183 }
 184
 185 void bch_data_verify(struct search *s)
 186 {
 187         char name[BDEVNAME_SIZE];
 188         struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
 189         struct closure *cl = &s->cl;
 190         struct bio *check;
 191         struct bio_vec *bv;
 192         int i;
 193
 194         if (!s->unaligned_bvec)
 195                 bio_for_each_segment(bv, s->orig_bio, i)
 196                         bv->bv_offset = 0, bv->bv_len = PAGE_SIZE;
 197
 198         check = bio_clone(s->orig_bio, GFP_NOIO);
 199         if (!check)
 200                 return;
 201
 202         if (bio_alloc_pages(check, GFP_NOIO))
 203                 goto out_put;
 204
 205         check->bi_rw            = READ_SYNC;
 206         check->bi_private       = cl;
 207         check->bi_end_io        = data_verify_endio;
 208
 209         closure_bio_submit(check, cl, &dc->disk);
 210         closure_sync(cl);
 211
 212         bio_for_each_segment(bv, s->orig_bio, i) {
 213                 void *p1 = kmap(bv->bv_page);
 214                 void *p2 = kmap(check->bi_io_vec[i].bv_page);
 215
 216                 if (memcmp(p1 + bv->bv_offset,
 217                            p2 + bv->bv_offset,
 218                            bv->bv_len))
 219                         printk(KERN_ERR
 220                                "bcache (%s): verify failed at sector %llu\n",
 221                                bdevname(dc->bdev, name),
 222                                (uint64_t) s->orig_bio->bi_sector);
 223
 224                 kunmap(bv->bv_page);
 225                 kunmap(check->bi_io_vec[i].bv_page);
 226         }
 227
 228         __bio_for_each_segment(bv, check, i, 0)
 229                 __free_page(bv->bv_page);
 230 out_put:
 231         bio_put(check);
 232 }
 233
 234 #endif
 235
 236 #ifdef CONFIG_BCACHE_EDEBUG
 237
 238 unsigned bch_count_data(struct btree *b)
 239 {
 240         unsigned ret = 0;
 241         struct btree_iter iter;
 242         struct bkey *k;
 243
 244         if (!b->level)
 245                 for_each_key(b, k, &iter)
 246                         ret += KEY_SIZE(k);
 247         return ret;
 248 }
 249
 250 static void vdump_bucket_and_panic(struct btree *b, const char *fmt,
 251                                    va_list args)
 252 {
 253         unsigned i;
 254         char buf[80];
 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         bch_btree_to_text(buf, sizeof(buf), b);
 266         panic("at %s\n", buf);
 267 }
 268
 269 void bch_check_key_order_msg(struct btree *b, struct bset *i,
 270                              const char *fmt, ...)
 271 {
 272         struct bkey *k;
 273
 274         if (!i->keys)
 275                 return;
 276
 277         for (k = i->start; bkey_next(k) < end(i); k = bkey_next(k))
 278                 if (skipped_backwards(b, k)) {
 279                         va_list args;
 280                         va_start(args, fmt);
 281
 282                         vdump_bucket_and_panic(b, fmt, args);
 283                         va_end(args);
 284                 }
 285 }
 286
 287 void bch_check_keys(struct btree *b, const char *fmt, ...)
 288 {
 289         va_list args;
 290         struct bkey *k, *p = NULL;
 291         struct btree_iter iter;
 292
 293         if (b->level)
 294                 return;
 295
 296         for_each_key(b, k, &iter) {
 297                 if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0) {
 298                         printk(KERN_ERR "Keys out of order:\n");
 299                         goto bug;
 300                 }
 301
 302                 if (bch_ptr_invalid(b, k))
 303                         continue;
 304
 305                 if (p && bkey_cmp(p, &START_KEY(k)) > 0) {
 306                         printk(KERN_ERR "Overlapping keys:\n");
 307                         goto bug;
 308                 }
 309                 p = k;
 310         }
 311         return;
 312 bug:
 313         va_start(args, fmt);
 314         vdump_bucket_and_panic(b, fmt, args);
 315         va_end(args);
 316 }
 317
 318 #endif
 319
 320 #ifdef CONFIG_DEBUG_FS
 321
 322 /* XXX: cache set refcounting */
 323
 324 struct dump_iterator {
 325         char                    buf[PAGE_SIZE];
 326         size_t                  bytes;
 327         struct cache_set        *c;
 328         struct keybuf           keys;
 329 };
 330
 331 static bool dump_pred(struct keybuf *buf, struct bkey *k)
 332 {
 333         return true;
 334 }
 335
 336 static ssize_t bch_dump_read(struct file *file, char __user *buf,
 337                              size_t size, loff_t *ppos)
 338 {
 339         struct dump_iterator *i = file->private_data;
 340         ssize_t ret = 0;
 341         char kbuf[80];
 342
 343         while (size) {
 344                 struct keybuf_key *w;
 345                 unsigned bytes = min(i->bytes, size);
 346
 347                 int err = copy_to_user(buf, i->buf, bytes);
 348                 if (err)
 349                         return err;
 350
 351                 ret      += bytes;
 352                 buf      += bytes;
 353                 size     -= bytes;
 354                 i->bytes -= bytes;
 355                 memmove(i->buf, i->buf + bytes, i->bytes);
 356
 357                 if (i->bytes)
 358                         break;
 359
 360                 w = bch_keybuf_next_rescan(i->c, &i->keys, &MAX_KEY, dump_pred);
 361                 if (!w)
 362                         break;
 363
 364                 bch_bkey_to_text(kbuf, sizeof(kbuf), &w->key);
 365                 i->bytes = snprintf(i->buf, PAGE_SIZE, "%s\n", kbuf);
 366                 bch_keybuf_del(&i->keys, w);
 367         }
 368
 369         return ret;
 370 }
 371
 372 static int bch_dump_open(struct inode *inode, struct file *file)
 373 {
 374         struct cache_set *c = inode->i_private;
 375         struct dump_iterator *i;
 376
 377         i = kzalloc(sizeof(struct dump_iterator), GFP_KERNEL);
 378         if (!i)
 379                 return -ENOMEM;
 380
 381         file->private_data = i;
 382         i->c = c;
 383         bch_keybuf_init(&i->keys);
 384         i->keys.last_scanned = KEY(0, 0, 0);
 385
 386         return 0;
 387 }
 388
 389 static int bch_dump_release(struct inode *inode, struct file *file)
 390 {
 391         kfree(file->private_data);
 392         return 0;
 393 }
 394
 395 static const struct file_operations cache_set_debug_ops = {
 396         .owner          = THIS_MODULE,
 397         .open           = bch_dump_open,
 398         .read           = bch_dump_read,
 399         .release        = bch_dump_release
 400 };
 401
 402 void bch_debug_init_cache_set(struct cache_set *c)
 403 {
 404         if (!IS_ERR_OR_NULL(debug)) {
 405                 char name[50];
 406                 snprintf(name, 50, "bcache-%pU", c->sb.set_uuid);
 407
 408                 c->debug = debugfs_create_file(name, 0400, debug, c,
 409                                                &cache_set_debug_ops);
 410         }
 411 }
 412
 413 #endif
 414
 415 void bch_debug_exit(void)
 416 {
 417         if (!IS_ERR_OR_NULL(debug))
 418                 debugfs_remove_recursive(debug);
 419 }
 420
 421 int __init bch_debug_init(struct kobject *kobj)
 422 {
 423         int ret = 0;
 424
 425         debug = debugfs_create_dir("bcache", NULL);
 426         return ret;
 427 }