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 12 #include <linux/console.h> 13 #include <linux/debugfs.h> 14 #include <linux/module.h> 15 #include <linux/random.h> 16 #include <linux/seq_file.h> 17 18 static struct dentry *debug; 19 20 const char *bch_ptr_status(struct cache_set *c, const struct bkey *k) 21 { 22 unsigned i; 23 24 for (i = 0; i < KEY_PTRS(k); i++) 25 if (ptr_available(c, k, i)) { 26 struct cache *ca = PTR_CACHE(c, k, i); 27 size_t bucket = PTR_BUCKET_NR(c, k, i); 28 size_t r = bucket_remainder(c, PTR_OFFSET(k, i)); 29 30 if (KEY_SIZE(k) + r > c->sb.bucket_size) 31 return "bad, length too big"; 32 if (bucket < ca->sb.first_bucket) 33 return "bad, short offset"; 34 if (bucket >= ca->sb.nbuckets) 35 return "bad, offset past end of device"; 36 if (ptr_stale(c, k, i)) 37 return "stale"; 38 } 39 40 if (!bkey_cmp(k, &ZERO_KEY)) 41 return "bad, null key"; 42 if (!KEY_PTRS(k)) 43 return "bad, no pointers"; 44 if (!KEY_SIZE(k)) 45 return "zeroed key"; 46 return ""; 47 } 48 49 int bch_bkey_to_text(char *buf, size_t size, const struct bkey *k) 50 { 51 unsigned i = 0; 52 char *out = buf, *end = buf + size; 53 54 #define p(...) (out += scnprintf(out, end - out, __VA_ARGS__)) 55 56 p("%llu:%llu len %llu -> [", KEY_INODE(k), KEY_START(k), KEY_SIZE(k)); 57 58 for (i = 0; i < KEY_PTRS(k); i++) { 59 if (i) 60 p(", "); 61 62 if (PTR_DEV(k, i) == PTR_CHECK_DEV) 63 p("check dev"); 64 else 65 p("%llu:%llu gen %llu", PTR_DEV(k, i), 66 PTR_OFFSET(k, i), PTR_GEN(k, i)); 67 } 68 69 p("]"); 70 71 if (KEY_DIRTY(k)) 72 p(" dirty"); 73 if (KEY_CSUM(k)) 74 p(" cs%llu %llx", KEY_CSUM(k), k->ptr[1]); 75 #undef p 76 return out - buf; 77 } 78 79 #ifdef CONFIG_BCACHE_DEBUG 80 81 static void dump_bset(struct btree *b, struct bset *i, unsigned set) 82 { 83 struct bkey *k, *next; 84 unsigned j; 85 char buf[80]; 86 87 for (k = i->start; k < bset_bkey_last(i); k = next) { 88 next = bkey_next(k); 89 90 bch_bkey_to_text(buf, sizeof(buf), k); 91 printk(KERN_ERR "b %u k %zi/%u: %s", set, 92 (uint64_t *) k - i->d, i->keys, buf); 93 94 for (j = 0; j < KEY_PTRS(k); j++) { 95 size_t n = PTR_BUCKET_NR(b->c, k, j); 96 printk(" bucket %zu", n); 97 98 if (n >= b->c->sb.first_bucket && n < b->c->sb.nbuckets) 99 printk(" prio %i", 100 PTR_BUCKET(b->c, k, j)->prio); 101 } 102 103 printk(" %s\n", bch_ptr_status(b->c, k)); 104 105 if (next < bset_bkey_last(i) && 106 bkey_cmp(k, !b->level ? &START_KEY(next) : next) > 0) 107 printk(KERN_ERR "Key skipped backwards\n"); 108 } 109 } 110 111 static void bch_dump_bucket(struct btree *b) 112 { 113 unsigned i; 114 115 console_lock(); 116 for (i = 0; i <= b->keys.nsets; i++) 117 dump_bset(b, b->keys.set[i].data, 118 bset_block_offset(b, b->keys.set[i].data)); 119 console_unlock(); 120 } 121 122 #define for_each_written_bset(b, start, i) \ 123 for (i = (start); \ 124 (void *) i < (void *) (start) + (KEY_SIZE(&b->key) << 9) &&\ 125 i->seq == (start)->seq; \ 126 i = (void *) i + set_blocks(i, block_bytes(b->c)) * \ 127 block_bytes(b->c)) 128 129 void bch_btree_verify(struct btree *b) 130 { 131 struct btree *v = b->c->verify_data; 132 struct bset *ondisk, *sorted, *inmemory; 133 struct bio *bio; 134 135 if (!b->c->verify || !b->c->verify_ondisk) 136 return; 137 138 down(&b->io_mutex); 139 mutex_lock(&b->c->verify_lock); 140 141 ondisk = b->c->verify_ondisk; 142 sorted = b->c->verify_data->keys.set->data; 143 inmemory = b->keys.set->data; 144 145 bkey_copy(&v->key, &b->key); 146 v->written = 0; 147 v->level = b->level; 148 v->keys.ops = b->keys.ops; 149 150 bio = bch_bbio_alloc(b->c); 151 bio->bi_bdev = PTR_CACHE(b->c, &b->key, 0)->bdev; 152 bio->bi_iter.bi_sector = PTR_OFFSET(&b->key, 0); 153 bio->bi_iter.bi_size = KEY_SIZE(&v->key) << 9; 154 bch_bio_map(bio, sorted); 155 156 submit_bio_wait(REQ_META|READ_SYNC, bio); 157 bch_bbio_free(bio, b->c); 158 159 memcpy(ondisk, sorted, KEY_SIZE(&v->key) << 9); 160 161 bch_btree_node_read_done(v); 162 sorted = v->keys.set->data; 163 164 if (inmemory->keys != sorted->keys || 165 memcmp(inmemory->start, 166 sorted->start, 167 (void *) bset_bkey_last(inmemory) - (void *) inmemory->start)) { 168 struct bset *i; 169 unsigned j; 170 171 console_lock(); 172 173 printk(KERN_ERR "*** in memory:\n"); 174 dump_bset(b, inmemory, 0); 175 176 printk(KERN_ERR "*** read back in:\n"); 177 dump_bset(v, sorted, 0); 178 179 for_each_written_bset(b, ondisk, i) { 180 unsigned block = ((void *) i - (void *) ondisk) / 181 block_bytes(b->c); 182 183 printk(KERN_ERR "*** on disk block %u:\n", block); 184 dump_bset(b, i, block); 185 } 186 187 printk(KERN_ERR "*** block %zu not written\n", 188 ((void *) i - (void *) ondisk) / block_bytes(b->c)); 189 190 for (j = 0; j < inmemory->keys; j++) 191 if (inmemory->d[j] != sorted->d[j]) 192 break; 193 194 printk(KERN_ERR "b->written %u\n", b->written); 195 196 console_unlock(); 197 panic("verify failed at %u\n", j); 198 } 199 200 mutex_unlock(&b->c->verify_lock); 201 up(&b->io_mutex); 202 } 203 204 void bch_data_verify(struct cached_dev *dc, struct bio *bio) 205 { 206 char name[BDEVNAME_SIZE]; 207 struct bio *check; 208 struct bio_vec bv, *bv2; 209 struct bvec_iter iter; 210 int i; 211 212 check = bio_clone(bio, GFP_NOIO); 213 if (!check) 214 return; 215 216 if (bio_alloc_pages(check, GFP_NOIO)) 217 goto out_put; 218 219 submit_bio_wait(READ_SYNC, check); 220 221 bio_for_each_segment(bv, bio, iter) { 222 void *p1 = kmap_atomic(bv.bv_page); 223 void *p2 = page_address(check->bi_io_vec[iter.bi_idx].bv_page); 224 225 cache_set_err_on(memcmp(p1 + bv.bv_offset, 226 p2 + bv.bv_offset, 227 bv.bv_len), 228 dc->disk.c, 229 "verify failed at dev %s sector %llu", 230 bdevname(dc->bdev, name), 231 (uint64_t) bio->bi_iter.bi_sector); 232 233 kunmap_atomic(p1); 234 } 235 236 bio_for_each_segment_all(bv2, check, i) 237 __free_page(bv2->bv_page); 238 out_put: 239 bio_put(check); 240 } 241 242 int __bch_count_data(struct btree *b) 243 { 244 unsigned ret = 0; 245 struct btree_iter iter; 246 struct bkey *k; 247 248 if (!b->level) 249 for_each_key(&b->keys, k, &iter) 250 ret += KEY_SIZE(k); 251 return ret; 252 } 253 254 void __bch_check_keys(struct btree *b, const char *fmt, ...) 255 { 256 va_list args; 257 struct bkey *k, *p = NULL; 258 struct btree_iter iter; 259 const char *err; 260 261 for_each_key(&b->keys, k, &iter) { 262 if (!b->level) { 263 err = "Keys out of order"; 264 if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0) 265 goto bug; 266 267 if (bch_ptr_invalid(&b->keys, k)) 268 continue; 269 270 err = "Overlapping keys"; 271 if (p && bkey_cmp(p, &START_KEY(k)) > 0) 272 goto bug; 273 } else { 274 if (bch_ptr_bad(&b->keys, k)) 275 continue; 276 277 err = "Duplicate keys"; 278 if (p && !bkey_cmp(p, k)) 279 goto bug; 280 } 281 p = k; 282 } 283 284 err = "Key larger than btree node key"; 285 if (p && bkey_cmp(p, &b->key) > 0) 286 goto bug; 287 288 return; 289 bug: 290 bch_dump_bucket(b); 291 292 va_start(args, fmt); 293 vprintk(fmt, args); 294 va_end(args); 295 296 panic("bcache error: %s:\n", err); 297 } 298 299 void bch_btree_iter_next_check(struct btree_iter *iter) 300 { 301 #if 0 302 struct bkey *k = iter->data->k, *next = bkey_next(k); 303 304 if (next < iter->data->end && 305 bkey_cmp(k, iter->b->level ? next : &START_KEY(next)) > 0) { 306 bch_dump_bucket(iter->b); 307 panic("Key skipped backwards\n"); 308 } 309 #endif 310 } 311 312 #endif 313 314 #ifdef CONFIG_DEBUG_FS 315 316 /* XXX: cache set refcounting */ 317 318 struct dump_iterator { 319 char buf[PAGE_SIZE]; 320 size_t bytes; 321 struct cache_set *c; 322 struct keybuf keys; 323 }; 324 325 static bool dump_pred(struct keybuf *buf, struct bkey *k) 326 { 327 return true; 328 } 329 330 static ssize_t bch_dump_read(struct file *file, char __user *buf, 331 size_t size, loff_t *ppos) 332 { 333 struct dump_iterator *i = file->private_data; 334 ssize_t ret = 0; 335 char kbuf[80]; 336 337 while (size) { 338 struct keybuf_key *w; 339 unsigned bytes = min(i->bytes, size); 340 341 int err = copy_to_user(buf, i->buf, bytes); 342 if (err) 343 return err; 344 345 ret += bytes; 346 buf += bytes; 347 size -= bytes; 348 i->bytes -= bytes; 349 memmove(i->buf, i->buf + bytes, i->bytes); 350 351 if (i->bytes) 352 break; 353 354 w = bch_keybuf_next_rescan(i->c, &i->keys, &MAX_KEY, dump_pred); 355 if (!w) 356 break; 357 358 bch_bkey_to_text(kbuf, sizeof(kbuf), &w->key); 359 i->bytes = snprintf(i->buf, PAGE_SIZE, "%s\n", kbuf); 360 bch_keybuf_del(&i->keys, w); 361 } 362 363 return ret; 364 } 365 366 static int bch_dump_open(struct inode *inode, struct file *file) 367 { 368 struct cache_set *c = inode->i_private; 369 struct dump_iterator *i; 370 371 i = kzalloc(sizeof(struct dump_iterator), GFP_KERNEL); 372 if (!i) 373 return -ENOMEM; 374 375 file->private_data = i; 376 i->c = c; 377 bch_keybuf_init(&i->keys); 378 i->keys.last_scanned = KEY(0, 0, 0); 379 380 return 0; 381 } 382 383 static int bch_dump_release(struct inode *inode, struct file *file) 384 { 385 kfree(file->private_data); 386 return 0; 387 } 388 389 static const struct file_operations cache_set_debug_ops = { 390 .owner = THIS_MODULE, 391 .open = bch_dump_open, 392 .read = bch_dump_read, 393 .release = bch_dump_release 394 }; 395 396 void bch_debug_init_cache_set(struct cache_set *c) 397 { 398 if (!IS_ERR_OR_NULL(debug)) { 399 char name[50]; 400 snprintf(name, 50, "bcache-%pU", c->sb.set_uuid); 401 402 c->debug = debugfs_create_file(name, 0400, debug, c, 403 &cache_set_debug_ops); 404 } 405 } 406 407 #endif 408 409 void bch_debug_exit(void) 410 { 411 if (!IS_ERR_OR_NULL(debug)) 412 debugfs_remove_recursive(debug); 413 } 414 415 int __init bch_debug_init(struct kobject *kobj) 416 { 417 int ret = 0; 418 419 debug = debugfs_create_dir("bcache", NULL); 420 return ret; 421 } 422