fs/bcachefs/debug.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Assorted bcachefs debug code
   4  *
   5  * Copyright 2010, 2011 Kent Overstreet <[email protected]>
   6  * Copyright 2012 Google, Inc.
   7  */
   8
   9 #include "bcachefs.h"
  10 #include "bkey_methods.h"
  11 #include "btree_cache.h"
  12 #include "btree_io.h"
  13 #include "btree_iter.h"
  14 #include "btree_locking.h"
  15 #include "btree_update.h"
  16 #include "btree_update_interior.h"
  17 #include "buckets.h"
  18 #include "debug.h"
  19 #include "error.h"
  20 #include "extents.h"
  21 #include "fsck.h"
  22 #include "inode.h"
  23 #include "super.h"
  24
  25 #include <linux/console.h>
  26 #include <linux/debugfs.h>
  27 #include <linux/module.h>
  28 #include <linux/random.h>
  29 #include <linux/seq_file.h>
  30
  31 static struct dentry *bch_debug;
  32
  33 static bool bch2_btree_verify_replica(struct bch_fs *c, struct btree *b,
  34                                       struct extent_ptr_decoded pick)
  35 {
  36         struct btree *v = c->verify_data;
  37         struct btree_node *n_ondisk = c->verify_ondisk;
  38         struct btree_node *n_sorted = c->verify_data->data;
  39         struct bset *sorted, *inmemory = &b->data->keys;
  40         struct bio *bio;
  41         bool failed = false, saw_error = false;
  42
  43         struct bch_dev *ca = bch2_dev_get_ioref(c, pick.ptr.dev, READ);
  44         if (!ca)
  45                 return false;
  46
  47         bio = bio_alloc_bioset(ca->disk_sb.bdev,
  48                                buf_pages(n_sorted, btree_buf_bytes(b)),
  49                                REQ_OP_READ|REQ_META,
  50                                GFP_NOFS,
  51                                &c->btree_bio);
  52         bio->bi_iter.bi_sector  = pick.ptr.offset;
  53         bch2_bio_map(bio, n_sorted, btree_buf_bytes(b));
  54
  55         submit_bio_wait(bio);
  56
  57         bio_put(bio);
  58         percpu_ref_put(&ca->io_ref);
  59
  60         memcpy(n_ondisk, n_sorted, btree_buf_bytes(b));
  61
  62         v->written = 0;
  63         if (bch2_btree_node_read_done(c, ca, v, false, &saw_error) || saw_error)
  64                 return false;
  65
  66         n_sorted = c->verify_data->data;
  67         sorted = &n_sorted->keys;
  68
  69         if (inmemory->u64s != sorted->u64s ||
  70             memcmp(inmemory->start,
  71                    sorted->start,
  72                    vstruct_end(inmemory) - (void *) inmemory->start)) {
  73                 unsigned offset = 0, sectors;
  74                 struct bset *i;
  75                 unsigned j;
  76
  77                 console_lock();
  78
  79                 printk(KERN_ERR "*** in memory:\n");
  80                 bch2_dump_bset(c, b, inmemory, 0);
  81
  82                 printk(KERN_ERR "*** read back in:\n");
  83                 bch2_dump_bset(c, v, sorted, 0);
  84
  85                 while (offset < v->written) {
  86                         if (!offset) {
  87                                 i = &n_ondisk->keys;
  88                                 sectors = vstruct_blocks(n_ondisk, c->block_bits) <<
  89                                         c->block_bits;
  90                         } else {
  91                                 struct btree_node_entry *bne =
  92                                         (void *) n_ondisk + (offset << 9);
  93                                 i = &bne->keys;
  94
  95                                 sectors = vstruct_blocks(bne, c->block_bits) <<
  96                                         c->block_bits;
  97                         }
  98
  99                         printk(KERN_ERR "*** on disk block %u:\n", offset);
 100                         bch2_dump_bset(c, b, i, offset);
 101
 102                         offset += sectors;
 103                 }
 104
 105                 for (j = 0; j < le16_to_cpu(inmemory->u64s); j++)
 106                         if (inmemory->_data[j] != sorted->_data[j])
 107                                 break;
 108
 109                 console_unlock();
 110                 bch_err(c, "verify failed at key %u", j);
 111
 112                 failed = true;
 113         }
 114
 115         if (v->written != b->written) {
 116                 bch_err(c, "written wrong: expected %u, got %u",
 117                         b->written, v->written);
 118                 failed = true;
 119         }
 120
 121         return failed;
 122 }
 123
 124 void __bch2_btree_verify(struct bch_fs *c, struct btree *b)
 125 {
 126         struct bkey_ptrs_c ptrs;
 127         struct extent_ptr_decoded p;
 128         const union bch_extent_entry *entry;
 129         struct btree *v;
 130         struct bset *inmemory = &b->data->keys;
 131         struct bkey_packed *k;
 132         bool failed = false;
 133
 134         if (c->opts.nochanges)
 135                 return;
 136
 137         bch2_btree_node_io_lock(b);
 138         mutex_lock(&c->verify_lock);
 139
 140         if (!c->verify_ondisk) {
 141                 c->verify_ondisk = kvmalloc(btree_buf_bytes(b), GFP_KERNEL);
 142                 if (!c->verify_ondisk)
 143                         goto out;
 144         }
 145
 146         if (!c->verify_data) {
 147                 c->verify_data = __bch2_btree_node_mem_alloc(c);
 148                 if (!c->verify_data)
 149                         goto out;
 150
 151                 list_del_init(&c->verify_data->list);
 152         }
 153
 154         BUG_ON(b->nsets != 1);
 155
 156         for (k = inmemory->start; k != vstruct_last(inmemory); k = bkey_p_next(k))
 157                 if (k->type == KEY_TYPE_btree_ptr_v2)
 158                         ((struct bch_btree_ptr_v2 *) bkeyp_val(&b->format, k))->mem_ptr = 0;
 159
 160         v = c->verify_data;
 161         bkey_copy(&v->key, &b->key);
 162         v->c.level      = b->c.level;
 163         v->c.btree_id   = b->c.btree_id;
 164         bch2_btree_keys_init(v);
 165
 166         ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(&b->key));
 167         bkey_for_each_ptr_decode(&b->key.k, ptrs, p, entry)
 168                 failed |= bch2_btree_verify_replica(c, b, p);
 169
 170         if (failed) {
 171                 struct printbuf buf = PRINTBUF;
 172
 173                 bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&b->key));
 174                 bch2_fs_fatal_error(c, ": btree node verify failed for: %s\n", buf.buf);
 175                 printbuf_exit(&buf);
 176         }
 177 out:
 178         mutex_unlock(&c->verify_lock);
 179         bch2_btree_node_io_unlock(b);
 180 }
 181
 182 void bch2_btree_node_ondisk_to_text(struct printbuf *out, struct bch_fs *c,
 183                                     const struct btree *b)
 184 {
 185         struct btree_node *n_ondisk = NULL;
 186         struct extent_ptr_decoded pick;
 187         struct bch_dev *ca;
 188         struct bio *bio = NULL;
 189         unsigned offset = 0;
 190         int ret;
 191
 192         if (bch2_bkey_pick_read_device(c, bkey_i_to_s_c(&b->key), NULL, &pick) <= 0) {
 193                 prt_printf(out, "error getting device to read from: invalid device\n");
 194                 return;
 195         }
 196
 197         ca = bch2_dev_get_ioref(c, pick.ptr.dev, READ);
 198         if (!ca) {
 199                 prt_printf(out, "error getting device to read from: not online\n");
 200                 return;
 201         }
 202
 203         n_ondisk = kvmalloc(btree_buf_bytes(b), GFP_KERNEL);
 204         if (!n_ondisk) {
 205                 prt_printf(out, "memory allocation failure\n");
 206                 goto out;
 207         }
 208
 209         bio = bio_alloc_bioset(ca->disk_sb.bdev,
 210                                buf_pages(n_ondisk, btree_buf_bytes(b)),
 211                                REQ_OP_READ|REQ_META,
 212                                GFP_NOFS,
 213                                &c->btree_bio);
 214         bio->bi_iter.bi_sector  = pick.ptr.offset;
 215         bch2_bio_map(bio, n_ondisk, btree_buf_bytes(b));
 216
 217         ret = submit_bio_wait(bio);
 218         if (ret) {
 219                 prt_printf(out, "IO error reading btree node: %s\n", bch2_err_str(ret));
 220                 goto out;
 221         }
 222
 223         while (offset < btree_sectors(c)) {
 224                 struct bset *i;
 225                 struct nonce nonce;
 226                 struct bch_csum csum;
 227                 struct bkey_packed *k;
 228                 unsigned sectors;
 229
 230                 if (!offset) {
 231                         i = &n_ondisk->keys;
 232
 233                         if (!bch2_checksum_type_valid(c, BSET_CSUM_TYPE(i))) {
 234                                 prt_printf(out, "unknown checksum type at offset %u: %llu\n",
 235                                            offset, BSET_CSUM_TYPE(i));
 236                                 goto out;
 237                         }
 238
 239                         nonce = btree_nonce(i, offset << 9);
 240                         csum = csum_vstruct(c, BSET_CSUM_TYPE(i), nonce, n_ondisk);
 241
 242                         if (bch2_crc_cmp(csum, n_ondisk->csum)) {
 243                                 prt_printf(out, "invalid checksum\n");
 244                                 goto out;
 245                         }
 246
 247                         bset_encrypt(c, i, offset << 9);
 248
 249                         sectors = vstruct_sectors(n_ondisk, c->block_bits);
 250                 } else {
 251                         struct btree_node_entry *bne = (void *) n_ondisk + (offset << 9);
 252
 253                         i = &bne->keys;
 254
 255                         if (i->seq != n_ondisk->keys.seq)
 256                                 break;
 257
 258                         if (!bch2_checksum_type_valid(c, BSET_CSUM_TYPE(i))) {
 259                                 prt_printf(out, "unknown checksum type at offset %u: %llu\n",
 260                                            offset, BSET_CSUM_TYPE(i));
 261                                 goto out;
 262                         }
 263
 264                         nonce = btree_nonce(i, offset << 9);
 265                         csum = csum_vstruct(c, BSET_CSUM_TYPE(i), nonce, bne);
 266
 267                         if (bch2_crc_cmp(csum, bne->csum)) {
 268                                 prt_printf(out, "invalid checksum");
 269                                 goto out;
 270                         }
 271
 272                         bset_encrypt(c, i, offset << 9);
 273
 274                         sectors = vstruct_sectors(bne, c->block_bits);
 275                 }
 276
 277                 prt_printf(out, "  offset %u version %u, journal seq %llu\n",
 278                            offset,
 279                            le16_to_cpu(i->version),
 280                            le64_to_cpu(i->journal_seq));
 281                 offset += sectors;
 282
 283                 printbuf_indent_add(out, 4);
 284
 285                 for (k = i->start; k != vstruct_last(i); k = bkey_p_next(k)) {
 286                         struct bkey u;
 287
 288                         bch2_bkey_val_to_text(out, c, bkey_disassemble(b, k, &u));
 289                         prt_newline(out);
 290                 }
 291
 292                 printbuf_indent_sub(out, 4);
 293         }
 294 out:
 295         if (bio)
 296                 bio_put(bio);
 297         kvfree(n_ondisk);
 298         percpu_ref_put(&ca->io_ref);
 299 }
 300
 301 #ifdef CONFIG_DEBUG_FS
 302
 303 /* XXX: bch_fs refcounting */
 304
 305 struct dump_iter {
 306         struct bch_fs           *c;
 307         enum btree_id           id;
 308         struct bpos             from;
 309         struct bpos             prev_node;
 310         u64                     iter;
 311
 312         struct printbuf         buf;
 313
 314         char __user             *ubuf;  /* destination user buffer */
 315         size_t                  size;   /* size of requested read */
 316         ssize_t                 ret;    /* bytes read so far */
 317 };
 318
 319 static ssize_t flush_buf(struct dump_iter *i)
 320 {
 321         if (i->buf.pos) {
 322                 size_t bytes = min_t(size_t, i->buf.pos, i->size);
 323                 int copied = bytes - copy_to_user(i->ubuf, i->buf.buf, bytes);
 324
 325                 i->ret   += copied;
 326                 i->ubuf  += copied;
 327                 i->size  -= copied;
 328                 i->buf.pos -= copied;
 329                 memmove(i->buf.buf, i->buf.buf + copied, i->buf.pos);
 330
 331                 if (copied != bytes)
 332                         return -EFAULT;
 333         }
 334
 335         return i->size ? 0 : i->ret;
 336 }
 337
 338 static int bch2_dump_open(struct inode *inode, struct file *file)
 339 {
 340         struct btree_debug *bd = inode->i_private;
 341         struct dump_iter *i;
 342
 343         i = kzalloc(sizeof(struct dump_iter), GFP_KERNEL);
 344         if (!i)
 345                 return -ENOMEM;
 346
 347         file->private_data = i;
 348         i->from = POS_MIN;
 349         i->iter = 0;
 350         i->c    = container_of(bd, struct bch_fs, btree_debug[bd->id]);
 351         i->id   = bd->id;
 352         i->buf  = PRINTBUF;
 353
 354         return 0;
 355 }
 356
 357 static int bch2_dump_release(struct inode *inode, struct file *file)
 358 {
 359         struct dump_iter *i = file->private_data;
 360
 361         printbuf_exit(&i->buf);
 362         kfree(i);
 363         return 0;
 364 }
 365
 366 static ssize_t bch2_read_btree(struct file *file, char __user *buf,
 367                                size_t size, loff_t *ppos)
 368 {
 369         struct dump_iter *i = file->private_data;
 370
 371         i->ubuf = buf;
 372         i->size = size;
 373         i->ret  = 0;
 374
 375         return flush_buf(i) ?:
 376                 bch2_trans_run(i->c,
 377                         for_each_btree_key(trans, iter, i->id, i->from,
 378                                            BTREE_ITER_prefetch|
 379                                            BTREE_ITER_all_snapshots, k, ({
 380                                 bch2_bkey_val_to_text(&i->buf, i->c, k);
 381                                 prt_newline(&i->buf);
 382                                 bch2_trans_unlock(trans);
 383                                 i->from = bpos_successor(iter.pos);
 384                                 flush_buf(i);
 385                         }))) ?:
 386                 i->ret;
 387 }
 388
 389 static const struct file_operations btree_debug_ops = {
 390         .owner          = THIS_MODULE,
 391         .open           = bch2_dump_open,
 392         .release        = bch2_dump_release,
 393         .read           = bch2_read_btree,
 394 };
 395
 396 static ssize_t bch2_read_btree_formats(struct file *file, char __user *buf,
 397                                        size_t size, loff_t *ppos)
 398 {
 399         struct dump_iter *i = file->private_data;
 400         struct btree_trans *trans;
 401         struct btree_iter iter;
 402         struct btree *b;
 403         ssize_t ret;
 404
 405         i->ubuf = buf;
 406         i->size = size;
 407         i->ret  = 0;
 408
 409         ret = flush_buf(i);
 410         if (ret)
 411                 return ret;
 412
 413         if (bpos_eq(SPOS_MAX, i->from))
 414                 return i->ret;
 415
 416         trans = bch2_trans_get(i->c);
 417 retry:
 418         bch2_trans_begin(trans);
 419
 420         for_each_btree_node(trans, iter, i->id, i->from, 0, b, ret) {
 421                 bch2_btree_node_to_text(&i->buf, i->c, b);
 422                 i->from = !bpos_eq(SPOS_MAX, b->key.k.p)
 423                         ? bpos_successor(b->key.k.p)
 424                         : b->key.k.p;
 425
 426                 ret = drop_locks_do(trans, flush_buf(i));
 427                 if (ret)
 428                         break;
 429         }
 430         bch2_trans_iter_exit(trans, &iter);
 431
 432         if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 433                 goto retry;
 434
 435         bch2_trans_put(trans);
 436
 437         if (!ret)
 438                 ret = flush_buf(i);
 439
 440         return ret ?: i->ret;
 441 }
 442
 443 static const struct file_operations btree_format_debug_ops = {
 444         .owner          = THIS_MODULE,
 445         .open           = bch2_dump_open,
 446         .release        = bch2_dump_release,
 447         .read           = bch2_read_btree_formats,
 448 };
 449
 450 static ssize_t bch2_read_bfloat_failed(struct file *file, char __user *buf,
 451                                        size_t size, loff_t *ppos)
 452 {
 453         struct dump_iter *i = file->private_data;
 454
 455         i->ubuf = buf;
 456         i->size = size;
 457         i->ret  = 0;
 458
 459         return flush_buf(i) ?:
 460                 bch2_trans_run(i->c,
 461                         for_each_btree_key(trans, iter, i->id, i->from,
 462                                            BTREE_ITER_prefetch|
 463                                            BTREE_ITER_all_snapshots, k, ({
 464                                 struct btree_path_level *l =
 465                                         &btree_iter_path(trans, &iter)->l[0];
 466                                 struct bkey_packed *_k =
 467                                         bch2_btree_node_iter_peek(&l->iter, l->b);
 468
 469                                 if (bpos_gt(l->b->key.k.p, i->prev_node)) {
 470                                         bch2_btree_node_to_text(&i->buf, i->c, l->b);
 471                                         i->prev_node = l->b->key.k.p;
 472                                 }
 473
 474                                 bch2_bfloat_to_text(&i->buf, l->b, _k);
 475                                 bch2_trans_unlock(trans);
 476                                 i->from = bpos_successor(iter.pos);
 477                                 flush_buf(i);
 478                         }))) ?:
 479                 i->ret;
 480 }
 481
 482 static const struct file_operations bfloat_failed_debug_ops = {
 483         .owner          = THIS_MODULE,
 484         .open           = bch2_dump_open,
 485         .release        = bch2_dump_release,
 486         .read           = bch2_read_bfloat_failed,
 487 };
 488
 489 static void bch2_cached_btree_node_to_text(struct printbuf *out, struct bch_fs *c,
 490                                            struct btree *b)
 491 {
 492         if (!out->nr_tabstops)
 493                 printbuf_tabstop_push(out, 32);
 494
 495         prt_printf(out, "%px btree=%s l=%u\n", b, bch2_btree_id_str(b->c.btree_id), b->c.level);
 496
 497         printbuf_indent_add(out, 2);
 498
 499         bch2_bkey_val_to_text(out, c, bkey_i_to_s_c(&b->key));
 500         prt_newline(out);
 501
 502         prt_printf(out, "flags:\t");
 503         prt_bitflags(out, bch2_btree_node_flags, b->flags);
 504         prt_newline(out);
 505
 506         prt_printf(out, "pcpu read locks:\t%u\n",       b->c.lock.readers != NULL);
 507         prt_printf(out, "written:\t%u\n",               b->written);
 508         prt_printf(out, "writes blocked:\t%u\n",        !list_empty_careful(&b->write_blocked));
 509         prt_printf(out, "will make reachable:\t%lx\n",  b->will_make_reachable);
 510
 511         prt_printf(out, "journal pin %px:\t%llu\n",
 512                    &b->writes[0].journal, b->writes[0].journal.seq);
 513         prt_printf(out, "journal pin %px:\t%llu\n",
 514                    &b->writes[1].journal, b->writes[1].journal.seq);
 515
 516         printbuf_indent_sub(out, 2);
 517 }
 518
 519 static ssize_t bch2_cached_btree_nodes_read(struct file *file, char __user *buf,
 520                                             size_t size, loff_t *ppos)
 521 {
 522         struct dump_iter *i = file->private_data;
 523         struct bch_fs *c = i->c;
 524         bool done = false;
 525         ssize_t ret = 0;
 526
 527         i->ubuf = buf;
 528         i->size = size;
 529         i->ret  = 0;
 530
 531         do {
 532                 struct bucket_table *tbl;
 533                 struct rhash_head *pos;
 534                 struct btree *b;
 535
 536                 ret = flush_buf(i);
 537                 if (ret)
 538                         return ret;
 539
 540                 rcu_read_lock();
 541                 i->buf.atomic++;
 542                 tbl = rht_dereference_rcu(c->btree_cache.table.tbl,
 543                                           &c->btree_cache.table);
 544                 if (i->iter < tbl->size) {
 545                         rht_for_each_entry_rcu(b, pos, tbl, i->iter, hash)
 546                                 bch2_cached_btree_node_to_text(&i->buf, c, b);
 547                         i->iter++;
 548                 } else {
 549                         done = true;
 550                 }
 551                 --i->buf.atomic;
 552                 rcu_read_unlock();
 553         } while (!done);
 554
 555         if (i->buf.allocation_failure)
 556                 ret = -ENOMEM;
 557
 558         if (!ret)
 559                 ret = flush_buf(i);
 560
 561         return ret ?: i->ret;
 562 }
 563
 564 static const struct file_operations cached_btree_nodes_ops = {
 565         .owner          = THIS_MODULE,
 566         .open           = bch2_dump_open,
 567         .release        = bch2_dump_release,
 568         .read           = bch2_cached_btree_nodes_read,
 569 };
 570
 571 static ssize_t bch2_btree_transactions_read(struct file *file, char __user *buf,
 572                                             size_t size, loff_t *ppos)
 573 {
 574         struct dump_iter *i = file->private_data;
 575         struct bch_fs *c = i->c;
 576         struct btree_trans *trans;
 577         ssize_t ret = 0;
 578         u32 seq;
 579
 580         i->ubuf = buf;
 581         i->size = size;
 582         i->ret  = 0;
 583 restart:
 584         seqmutex_lock(&c->btree_trans_lock);
 585         list_for_each_entry(trans, &c->btree_trans_list, list) {
 586                 struct task_struct *task = READ_ONCE(trans->locking_wait.task);
 587
 588                 if (!task || task->pid <= i->iter)
 589                         continue;
 590
 591                 closure_get(&trans->ref);
 592                 seq = seqmutex_seq(&c->btree_trans_lock);
 593                 seqmutex_unlock(&c->btree_trans_lock);
 594
 595                 ret = flush_buf(i);
 596                 if (ret) {
 597                         closure_put(&trans->ref);
 598                         goto unlocked;
 599                 }
 600
 601                 bch2_btree_trans_to_text(&i->buf, trans);
 602
 603                 prt_printf(&i->buf, "backtrace:\n");
 604                 printbuf_indent_add(&i->buf, 2);
 605                 bch2_prt_task_backtrace(&i->buf, task, 0, GFP_KERNEL);
 606                 printbuf_indent_sub(&i->buf, 2);
 607                 prt_newline(&i->buf);
 608
 609                 i->iter = task->pid;
 610
 611                 closure_put(&trans->ref);
 612
 613                 if (!seqmutex_relock(&c->btree_trans_lock, seq))
 614                         goto restart;
 615         }
 616         seqmutex_unlock(&c->btree_trans_lock);
 617 unlocked:
 618         if (i->buf.allocation_failure)
 619                 ret = -ENOMEM;
 620
 621         if (!ret)
 622                 ret = flush_buf(i);
 623
 624         return ret ?: i->ret;
 625 }
 626
 627 static const struct file_operations btree_transactions_ops = {
 628         .owner          = THIS_MODULE,
 629         .open           = bch2_dump_open,
 630         .release        = bch2_dump_release,
 631         .read           = bch2_btree_transactions_read,
 632 };
 633
 634 static ssize_t bch2_journal_pins_read(struct file *file, char __user *buf,
 635                                       size_t size, loff_t *ppos)
 636 {
 637         struct dump_iter *i = file->private_data;
 638         struct bch_fs *c = i->c;
 639         bool done = false;
 640         int err;
 641
 642         i->ubuf = buf;
 643         i->size = size;
 644         i->ret  = 0;
 645
 646         while (1) {
 647                 err = flush_buf(i);
 648                 if (err)
 649                         return err;
 650
 651                 if (!i->size)
 652                         break;
 653
 654                 if (done)
 655                         break;
 656
 657                 done = bch2_journal_seq_pins_to_text(&i->buf, &c->journal, &i->iter);
 658                 i->iter++;
 659         }
 660
 661         if (i->buf.allocation_failure)
 662                 return -ENOMEM;
 663
 664         return i->ret;
 665 }
 666
 667 static const struct file_operations journal_pins_ops = {
 668         .owner          = THIS_MODULE,
 669         .open           = bch2_dump_open,
 670         .release        = bch2_dump_release,
 671         .read           = bch2_journal_pins_read,
 672 };
 673
 674 static ssize_t bch2_btree_updates_read(struct file *file, char __user *buf,
 675                                        size_t size, loff_t *ppos)
 676 {
 677         struct dump_iter *i = file->private_data;
 678         struct bch_fs *c = i->c;
 679         int err;
 680
 681         i->ubuf = buf;
 682         i->size = size;
 683         i->ret  = 0;
 684
 685         if (!i->iter) {
 686                 bch2_btree_updates_to_text(&i->buf, c);
 687                 i->iter++;
 688         }
 689
 690         err = flush_buf(i);
 691         if (err)
 692                 return err;
 693
 694         if (i->buf.allocation_failure)
 695                 return -ENOMEM;
 696
 697         return i->ret;
 698 }
 699
 700 static const struct file_operations btree_updates_ops = {
 701         .owner          = THIS_MODULE,
 702         .open           = bch2_dump_open,
 703         .release        = bch2_dump_release,
 704         .read           = bch2_btree_updates_read,
 705 };
 706
 707 static int btree_transaction_stats_open(struct inode *inode, struct file *file)
 708 {
 709         struct bch_fs *c = inode->i_private;
 710         struct dump_iter *i;
 711
 712         i = kzalloc(sizeof(struct dump_iter), GFP_KERNEL);
 713         if (!i)
 714                 return -ENOMEM;
 715
 716         i->iter = 1;
 717         i->c    = c;
 718         i->buf  = PRINTBUF;
 719         file->private_data = i;
 720
 721         return 0;
 722 }
 723
 724 static int btree_transaction_stats_release(struct inode *inode, struct file *file)
 725 {
 726         struct dump_iter *i = file->private_data;
 727
 728         printbuf_exit(&i->buf);
 729         kfree(i);
 730
 731         return 0;
 732 }
 733
 734 static ssize_t btree_transaction_stats_read(struct file *file, char __user *buf,
 735                                             size_t size, loff_t *ppos)
 736 {
 737         struct dump_iter        *i = file->private_data;
 738         struct bch_fs *c = i->c;
 739         int err;
 740
 741         i->ubuf = buf;
 742         i->size = size;
 743         i->ret  = 0;
 744
 745         while (1) {
 746                 struct btree_transaction_stats *s = &c->btree_transaction_stats[i->iter];
 747
 748                 err = flush_buf(i);
 749                 if (err)
 750                         return err;
 751
 752                 if (!i->size)
 753                         break;
 754
 755                 if (i->iter == ARRAY_SIZE(bch2_btree_transaction_fns) ||
 756                     !bch2_btree_transaction_fns[i->iter])
 757                         break;
 758
 759                 prt_printf(&i->buf, "%s:\n", bch2_btree_transaction_fns[i->iter]);
 760                 printbuf_indent_add(&i->buf, 2);
 761
 762                 mutex_lock(&s->lock);
 763
 764                 prt_printf(&i->buf, "Max mem used: %u\n", s->max_mem);
 765                 prt_printf(&i->buf, "Transaction duration:\n");
 766
 767                 printbuf_indent_add(&i->buf, 2);
 768                 bch2_time_stats_to_text(&i->buf, &s->duration);
 769                 printbuf_indent_sub(&i->buf, 2);
 770
 771                 if (IS_ENABLED(CONFIG_BCACHEFS_LOCK_TIME_STATS)) {
 772                         prt_printf(&i->buf, "Lock hold times:\n");
 773
 774                         printbuf_indent_add(&i->buf, 2);
 775                         bch2_time_stats_to_text(&i->buf, &s->lock_hold_times);
 776                         printbuf_indent_sub(&i->buf, 2);
 777                 }
 778
 779                 if (s->max_paths_text) {
 780                         prt_printf(&i->buf, "Maximum allocated btree paths (%u):\n", s->nr_max_paths);
 781
 782                         printbuf_indent_add(&i->buf, 2);
 783                         prt_str_indented(&i->buf, s->max_paths_text);
 784                         printbuf_indent_sub(&i->buf, 2);
 785                 }
 786
 787                 mutex_unlock(&s->lock);
 788
 789                 printbuf_indent_sub(&i->buf, 2);
 790                 prt_newline(&i->buf);
 791                 i->iter++;
 792         }
 793
 794         if (i->buf.allocation_failure)
 795                 return -ENOMEM;
 796
 797         return i->ret;
 798 }
 799
 800 static const struct file_operations btree_transaction_stats_op = {
 801         .owner          = THIS_MODULE,
 802         .open           = btree_transaction_stats_open,
 803         .release        = btree_transaction_stats_release,
 804         .read           = btree_transaction_stats_read,
 805 };
 806
 807 static ssize_t bch2_btree_deadlock_read(struct file *file, char __user *buf,
 808                                             size_t size, loff_t *ppos)
 809 {
 810         struct dump_iter *i = file->private_data;
 811         struct bch_fs *c = i->c;
 812         struct btree_trans *trans;
 813         ssize_t ret = 0;
 814         u32 seq;
 815
 816         i->ubuf = buf;
 817         i->size = size;
 818         i->ret  = 0;
 819
 820         if (i->iter)
 821                 goto out;
 822 restart:
 823         seqmutex_lock(&c->btree_trans_lock);
 824         list_for_each_entry(trans, &c->btree_trans_list, list) {
 825                 struct task_struct *task = READ_ONCE(trans->locking_wait.task);
 826
 827                 if (!task || task->pid <= i->iter)
 828                         continue;
 829
 830                 closure_get(&trans->ref);
 831                 seq = seqmutex_seq(&c->btree_trans_lock);
 832                 seqmutex_unlock(&c->btree_trans_lock);
 833
 834                 ret = flush_buf(i);
 835                 if (ret) {
 836                         closure_put(&trans->ref);
 837                         goto out;
 838                 }
 839
 840                 bch2_check_for_deadlock(trans, &i->buf);
 841
 842                 i->iter = task->pid;
 843
 844                 closure_put(&trans->ref);
 845
 846                 if (!seqmutex_relock(&c->btree_trans_lock, seq))
 847                         goto restart;
 848         }
 849         seqmutex_unlock(&c->btree_trans_lock);
 850 out:
 851         if (i->buf.allocation_failure)
 852                 ret = -ENOMEM;
 853
 854         if (!ret)
 855                 ret = flush_buf(i);
 856
 857         return ret ?: i->ret;
 858 }
 859
 860 static const struct file_operations btree_deadlock_ops = {
 861         .owner          = THIS_MODULE,
 862         .open           = bch2_dump_open,
 863         .release        = bch2_dump_release,
 864         .read           = bch2_btree_deadlock_read,
 865 };
 866
 867 void bch2_fs_debug_exit(struct bch_fs *c)
 868 {
 869         if (!IS_ERR_OR_NULL(c->fs_debug_dir))
 870                 debugfs_remove_recursive(c->fs_debug_dir);
 871 }
 872
 873 static void bch2_fs_debug_btree_init(struct bch_fs *c, struct btree_debug *bd)
 874 {
 875         struct dentry *d;
 876
 877         d = debugfs_create_dir(bch2_btree_id_str(bd->id), c->btree_debug_dir);
 878
 879         debugfs_create_file("keys", 0400, d, bd, &btree_debug_ops);
 880
 881         debugfs_create_file("formats", 0400, d, bd, &btree_format_debug_ops);
 882
 883         debugfs_create_file("bfloat-failed", 0400, d, bd,
 884                             &bfloat_failed_debug_ops);
 885 }
 886
 887 void bch2_fs_debug_init(struct bch_fs *c)
 888 {
 889         struct btree_debug *bd;
 890         char name[100];
 891
 892         if (IS_ERR_OR_NULL(bch_debug))
 893                 return;
 894
 895         snprintf(name, sizeof(name), "%pU", c->sb.user_uuid.b);
 896         c->fs_debug_dir = debugfs_create_dir(name, bch_debug);
 897         if (IS_ERR_OR_NULL(c->fs_debug_dir))
 898                 return;
 899
 900         debugfs_create_file("cached_btree_nodes", 0400, c->fs_debug_dir,
 901                             c->btree_debug, &cached_btree_nodes_ops);
 902
 903         debugfs_create_file("btree_transactions", 0400, c->fs_debug_dir,
 904                             c->btree_debug, &btree_transactions_ops);
 905
 906         debugfs_create_file("journal_pins", 0400, c->fs_debug_dir,
 907                             c->btree_debug, &journal_pins_ops);
 908
 909         debugfs_create_file("btree_updates", 0400, c->fs_debug_dir,
 910                             c->btree_debug, &btree_updates_ops);
 911
 912         debugfs_create_file("btree_transaction_stats", 0400, c->fs_debug_dir,
 913                             c, &btree_transaction_stats_op);
 914
 915         debugfs_create_file("btree_deadlock", 0400, c->fs_debug_dir,
 916                             c->btree_debug, &btree_deadlock_ops);
 917
 918         c->btree_debug_dir = debugfs_create_dir("btrees", c->fs_debug_dir);
 919         if (IS_ERR_OR_NULL(c->btree_debug_dir))
 920                 return;
 921
 922         for (bd = c->btree_debug;
 923              bd < c->btree_debug + ARRAY_SIZE(c->btree_debug);
 924              bd++) {
 925                 bd->id = bd - c->btree_debug;
 926                 bch2_fs_debug_btree_init(c, bd);
 927         }
 928 }
 929
 930 #endif
 931
 932 void bch2_debug_exit(void)
 933 {
 934         if (!IS_ERR_OR_NULL(bch_debug))
 935                 debugfs_remove_recursive(bch_debug);
 936 }
 937
 938 int __init bch2_debug_init(void)
 939 {
 940         bch_debug = debugfs_create_dir("bcachefs", NULL);
 941         return 0;
 942 }