git.sesse.net Git - bcachefs-tools-debian/blob - libbcachefs/debug.c

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