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

   1 /*
   2  * Copyright (C) 2010 Kent Overstreet <kent.overstreet@gmail.com>
   3  * Copyright (C) 2014 Datera Inc.
   4  */
   5
   6 #include "bcachefs.h"
   7 #include "alloc_background.h"
   8 #include "alloc_foreground.h"
   9 #include "bkey_methods.h"
  10 #include "btree_locking.h"
  11 #include "btree_update_interior.h"
  12 #include "btree_io.h"
  13 #include "btree_gc.h"
  14 #include "buckets.h"
  15 #include "clock.h"
  16 #include "debug.h"
  17 #include "ec.h"
  18 #include "error.h"
  19 #include "extents.h"
  20 #include "journal.h"
  21 #include "journal_io.h"
  22 #include "keylist.h"
  23 #include "move.h"
  24 #include "replicas.h"
  25 #include "super-io.h"
  26
  27 #include <linux/slab.h>
  28 #include <linux/bitops.h>
  29 #include <linux/freezer.h>
  30 #include <linux/kthread.h>
  31 #include <linux/preempt.h>
  32 #include <linux/rcupdate.h>
  33 #include <linux/sched/task.h>
  34 #include <trace/events/bcachefs.h>
  35
  36 static inline void __gc_pos_set(struct bch_fs *c, struct gc_pos new_pos)
  37 {
  38         write_seqcount_begin(&c->gc_pos_lock);
  39         c->gc_pos = new_pos;
  40         write_seqcount_end(&c->gc_pos_lock);
  41 }
  42
  43 static inline void gc_pos_set(struct bch_fs *c, struct gc_pos new_pos)
  44 {
  45         BUG_ON(gc_pos_cmp(new_pos, c->gc_pos) <= 0);
  46         __gc_pos_set(c, new_pos);
  47 }
  48
  49 /* range_checks - for validating min/max pos of each btree node: */
  50
  51 struct range_checks {
  52         struct range_level {
  53                 struct bpos     min;
  54                 struct bpos     max;
  55         }                       l[BTREE_MAX_DEPTH];
  56         unsigned                depth;
  57 };
  58
  59 static void btree_node_range_checks_init(struct range_checks *r, unsigned depth)
  60 {
  61         unsigned i;
  62
  63         for (i = 0; i < BTREE_MAX_DEPTH; i++)
  64                 r->l[i].min = r->l[i].max = POS_MIN;
  65         r->depth = depth;
  66 }
  67
  68 static void btree_node_range_checks(struct bch_fs *c, struct btree *b,
  69                                     struct range_checks *r)
  70 {
  71         struct range_level *l = &r->l[b->level];
  72
  73         struct bpos expected_min = bkey_cmp(l->min, l->max)
  74                 ? btree_type_successor(b->btree_id, l->max)
  75                 : l->max;
  76
  77         bch2_fs_inconsistent_on(bkey_cmp(b->data->min_key, expected_min), c,
  78                 "btree node has incorrect min key: %llu:%llu != %llu:%llu",
  79                 b->data->min_key.inode,
  80                 b->data->min_key.offset,
  81                 expected_min.inode,
  82                 expected_min.offset);
  83
  84         l->max = b->data->max_key;
  85
  86         if (b->level > r->depth) {
  87                 l = &r->l[b->level - 1];
  88
  89                 bch2_fs_inconsistent_on(bkey_cmp(b->data->min_key, l->min), c,
  90                         "btree node min doesn't match min of child nodes: %llu:%llu != %llu:%llu",
  91                         b->data->min_key.inode,
  92                         b->data->min_key.offset,
  93                         l->min.inode,
  94                         l->min.offset);
  95
  96                 bch2_fs_inconsistent_on(bkey_cmp(b->data->max_key, l->max), c,
  97                         "btree node max doesn't match max of child nodes: %llu:%llu != %llu:%llu",
  98                         b->data->max_key.inode,
  99                         b->data->max_key.offset,
 100                         l->max.inode,
 101                         l->max.offset);
 102
 103                 if (bkey_cmp(b->data->max_key, POS_MAX))
 104                         l->min = l->max =
 105                                 btree_type_successor(b->btree_id,
 106                                                      b->data->max_key);
 107         }
 108 }
 109
 110 /* marking of btree keys/nodes: */
 111
 112 static int bch2_gc_mark_key(struct bch_fs *c, struct bkey_s_c k,
 113                             u8 *max_stale, bool initial)
 114 {
 115         struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
 116         const struct bch_extent_ptr *ptr;
 117         unsigned flags =
 118                 BCH_BUCKET_MARK_GC|
 119                 (initial ? BCH_BUCKET_MARK_NOATOMIC : 0);
 120         int ret = 0;
 121
 122         if (initial) {
 123                 BUG_ON(journal_seq_verify(c) &&
 124                        k.k->version.lo > journal_cur_seq(&c->journal));
 125
 126                 if (k.k->version.lo > atomic64_read(&c->key_version))
 127                         atomic64_set(&c->key_version, k.k->version.lo);
 128
 129                 if (test_bit(BCH_FS_REBUILD_REPLICAS, &c->flags) ||
 130                     fsck_err_on(!bch2_bkey_replicas_marked(c, k, false), c,
 131                                 "superblock not marked as containing replicas (type %u)",
 132                                 k.k->type)) {
 133                         ret = bch2_mark_bkey_replicas(c, k);
 134                         if (ret)
 135                                 return ret;
 136                 }
 137
 138                 bkey_for_each_ptr(ptrs, ptr) {
 139                         struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
 140                         struct bucket *g = PTR_BUCKET(ca, ptr, true);
 141                         struct bucket *g2 = PTR_BUCKET(ca, ptr, false);
 142
 143                         if (mustfix_fsck_err_on(!g->gen_valid, c,
 144                                         "found ptr with missing gen in alloc btree,\n"
 145                                         "type %u gen %u",
 146                                         k.k->type, ptr->gen)) {
 147                                 g2->_mark.gen   = g->_mark.gen          = ptr->gen;
 148                                 g2->_mark.dirty = g->_mark.dirty        = true;
 149                                 g2->gen_valid   = g->gen_valid          = true;
 150                         }
 151
 152                         if (mustfix_fsck_err_on(gen_cmp(ptr->gen, g->mark.gen) > 0, c,
 153                                         "%u ptr gen in the future: %u > %u",
 154                                         k.k->type, ptr->gen, g->mark.gen)) {
 155                                 g2->_mark.gen   = g->_mark.gen          = ptr->gen;
 156                                 g2->_mark.dirty = g->_mark.dirty        = true;
 157                                 g2->gen_valid   = g->gen_valid          = true;
 158                                 set_bit(BCH_FS_FIXED_GENS, &c->flags);
 159                         }
 160                 }
 161         }
 162
 163         bkey_for_each_ptr(ptrs, ptr) {
 164                 struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
 165                 struct bucket *g = PTR_BUCKET(ca, ptr, true);
 166
 167                 if (gen_after(g->oldest_gen, ptr->gen))
 168                         g->oldest_gen = ptr->gen;
 169
 170                 *max_stale = max(*max_stale, ptr_stale(ca, ptr));
 171         }
 172
 173         bch2_mark_key(c, k, true, k.k->size, NULL, 0, flags);
 174 fsck_err:
 175         return ret;
 176 }
 177
 178 static int btree_gc_mark_node(struct bch_fs *c, struct btree *b,
 179                               u8 *max_stale, bool initial)
 180 {
 181         struct btree_node_iter iter;
 182         struct bkey unpacked;
 183         struct bkey_s_c k;
 184         int ret = 0;
 185
 186         *max_stale = 0;
 187
 188         if (!btree_node_type_needs_gc(btree_node_type(b)))
 189                 return 0;
 190
 191         for_each_btree_node_key_unpack(b, k, &iter,
 192                                        &unpacked) {
 193                 bch2_bkey_debugcheck(c, b, k);
 194
 195                 ret = bch2_gc_mark_key(c, k, max_stale, initial);
 196                 if (ret)
 197                         break;
 198         }
 199
 200         return ret;
 201 }
 202
 203 static int bch2_gc_btree(struct bch_fs *c, enum btree_id btree_id,
 204                          bool initial, bool metadata_only)
 205 {
 206         struct btree_trans trans;
 207         struct btree_iter *iter;
 208         struct btree *b;
 209         struct range_checks r;
 210         unsigned depth = btree_node_type_needs_gc(btree_id) ? 0 : 1;
 211         u8 max_stale;
 212         int ret = 0;
 213
 214         bch2_trans_init(&trans, c);
 215
 216         gc_pos_set(c, gc_pos_btree(btree_id, POS_MIN, 0));
 217
 218         /*
 219          * if expensive_debug_checks is on, run range_checks on all leaf nodes:
 220          *
 221          * and on startup, we have to read every btree node (XXX: only if it was
 222          * an unclean shutdown)
 223          */
 224         if (metadata_only)
 225                 depth = 1;
 226         else if (initial || expensive_debug_checks(c))
 227                 depth = 0;
 228
 229         btree_node_range_checks_init(&r, depth);
 230
 231         __for_each_btree_node(&trans, iter, btree_id, POS_MIN,
 232                               0, depth, BTREE_ITER_PREFETCH, b) {
 233                 btree_node_range_checks(c, b, &r);
 234
 235                 bch2_verify_btree_nr_keys(b);
 236
 237                 gc_pos_set(c, gc_pos_btree_node(b));
 238
 239                 ret = btree_gc_mark_node(c, b, &max_stale, initial);
 240                 if (ret)
 241                         break;
 242
 243                 if (!initial) {
 244                         if (max_stale > 64)
 245                                 bch2_btree_node_rewrite(c, iter,
 246                                                 b->data->keys.seq,
 247                                                 BTREE_INSERT_USE_RESERVE|
 248                                                 BTREE_INSERT_NOWAIT|
 249                                                 BTREE_INSERT_GC_LOCK_HELD);
 250                         else if (!btree_gc_rewrite_disabled(c) &&
 251                                  (btree_gc_always_rewrite(c) || max_stale > 16))
 252                                 bch2_btree_node_rewrite(c, iter,
 253                                                 b->data->keys.seq,
 254                                                 BTREE_INSERT_NOWAIT|
 255                                                 BTREE_INSERT_GC_LOCK_HELD);
 256                 }
 257
 258                 bch2_trans_cond_resched(&trans);
 259         }
 260         ret = bch2_trans_exit(&trans) ?: ret;
 261         if (ret)
 262                 return ret;
 263
 264         mutex_lock(&c->btree_root_lock);
 265         b = c->btree_roots[btree_id].b;
 266         if (!btree_node_fake(b))
 267                 ret = bch2_gc_mark_key(c, bkey_i_to_s_c(&b->key),
 268                                        &max_stale, initial);
 269         gc_pos_set(c, gc_pos_btree_root(b->btree_id));
 270         mutex_unlock(&c->btree_root_lock);
 271
 272         return ret;
 273 }
 274
 275 static inline int btree_id_gc_phase_cmp(enum btree_id l, enum btree_id r)
 276 {
 277         return  (int) btree_id_to_gc_phase(l) -
 278                 (int) btree_id_to_gc_phase(r);
 279 }
 280
 281 static int bch2_gc_btrees(struct bch_fs *c, struct list_head *journal,
 282                           bool initial, bool metadata_only)
 283 {
 284         enum btree_id ids[BTREE_ID_NR];
 285         u8 max_stale;
 286         unsigned i;
 287
 288         for (i = 0; i < BTREE_ID_NR; i++)
 289                 ids[i] = i;
 290         bubble_sort(ids, BTREE_ID_NR, btree_id_gc_phase_cmp);
 291
 292         for (i = 0; i < BTREE_ID_NR; i++) {
 293                 enum btree_id id = ids[i];
 294                 enum btree_node_type type = __btree_node_type(0, id);
 295
 296                 int ret = bch2_gc_btree(c, id, initial, metadata_only);
 297                 if (ret)
 298                         return ret;
 299
 300                 if (journal && !metadata_only &&
 301                     btree_node_type_needs_gc(type)) {
 302                         struct bkey_i *k, *n;
 303                         struct jset_entry *j;
 304                         struct journal_replay *r;
 305                         int ret;
 306
 307                         list_for_each_entry(r, journal, list)
 308                                 for_each_jset_key(k, n, j, &r->j) {
 309                                         if (type == __btree_node_type(j->level, j->btree_id)) {
 310                                                 ret = bch2_gc_mark_key(c,
 311                                                         bkey_i_to_s_c(k),
 312                                                         &max_stale, initial);
 313                                                 if (ret)
 314                                                         return ret;
 315                                         }
 316                                 }
 317                 }
 318         }
 319
 320         return 0;
 321 }
 322
 323 static void mark_metadata_sectors(struct bch_fs *c, struct bch_dev *ca,
 324                                   u64 start, u64 end,
 325                                   enum bch_data_type type,
 326                                   unsigned flags)
 327 {
 328         u64 b = sector_to_bucket(ca, start);
 329
 330         do {
 331                 unsigned sectors =
 332                         min_t(u64, bucket_to_sector(ca, b + 1), end) - start;
 333
 334                 bch2_mark_metadata_bucket(c, ca, b, type, sectors,
 335                                           gc_phase(GC_PHASE_SB), flags);
 336                 b++;
 337                 start += sectors;
 338         } while (start < end);
 339 }
 340
 341 void bch2_mark_dev_superblock(struct bch_fs *c, struct bch_dev *ca,
 342                               unsigned flags)
 343 {
 344         struct bch_sb_layout *layout = &ca->disk_sb.sb->layout;
 345         unsigned i;
 346         u64 b;
 347
 348         /*
 349          * This conditional is kind of gross, but we may be called from the
 350          * device add path, before the new device has actually been added to the
 351          * running filesystem:
 352          */
 353         if (c) {
 354                 lockdep_assert_held(&c->sb_lock);
 355                 percpu_down_read_preempt_disable(&c->mark_lock);
 356         } else {
 357                 preempt_disable();
 358         }
 359
 360         for (i = 0; i < layout->nr_superblocks; i++) {
 361                 u64 offset = le64_to_cpu(layout->sb_offset[i]);
 362
 363                 if (offset == BCH_SB_SECTOR)
 364                         mark_metadata_sectors(c, ca, 0, BCH_SB_SECTOR,
 365                                               BCH_DATA_SB, flags);
 366
 367                 mark_metadata_sectors(c, ca, offset,
 368                                       offset + (1 << layout->sb_max_size_bits),
 369                                       BCH_DATA_SB, flags);
 370         }
 371
 372         for (i = 0; i < ca->journal.nr; i++) {
 373                 b = ca->journal.buckets[i];
 374                 bch2_mark_metadata_bucket(c, ca, b, BCH_DATA_JOURNAL,
 375                                           ca->mi.bucket_size,
 376                                           gc_phase(GC_PHASE_SB), flags);
 377         }
 378
 379         if (c) {
 380                 percpu_up_read_preempt_enable(&c->mark_lock);
 381         } else {
 382                 preempt_enable();
 383         }
 384 }
 385
 386 static void bch2_mark_superblocks(struct bch_fs *c)
 387 {
 388         struct bch_dev *ca;
 389         unsigned i;
 390
 391         mutex_lock(&c->sb_lock);
 392         gc_pos_set(c, gc_phase(GC_PHASE_SB));
 393
 394         for_each_online_member(ca, c, i)
 395                 bch2_mark_dev_superblock(c, ca, BCH_BUCKET_MARK_GC);
 396         mutex_unlock(&c->sb_lock);
 397 }
 398
 399 /* Also see bch2_pending_btree_node_free_insert_done() */
 400 static void bch2_mark_pending_btree_node_frees(struct bch_fs *c)
 401 {
 402         struct btree_update *as;
 403         struct pending_btree_node_free *d;
 404
 405         mutex_lock(&c->btree_interior_update_lock);
 406         gc_pos_set(c, gc_phase(GC_PHASE_PENDING_DELETE));
 407
 408         for_each_pending_btree_node_free(c, as, d)
 409                 if (d->index_update_done)
 410                         bch2_mark_key(c, bkey_i_to_s_c(&d->key),
 411                                       true, 0, NULL, 0,
 412                                       BCH_BUCKET_MARK_GC);
 413
 414         mutex_unlock(&c->btree_interior_update_lock);
 415 }
 416
 417 static void bch2_mark_allocator_buckets(struct bch_fs *c)
 418 {
 419         struct bch_dev *ca;
 420         struct open_bucket *ob;
 421         size_t i, j, iter;
 422         unsigned ci;
 423
 424         percpu_down_read_preempt_disable(&c->mark_lock);
 425
 426         spin_lock(&c->freelist_lock);
 427         gc_pos_set(c, gc_pos_alloc(c, NULL));
 428
 429         for_each_member_device(ca, c, ci) {
 430                 fifo_for_each_entry(i, &ca->free_inc, iter)
 431                         bch2_mark_alloc_bucket(c, ca, i, true,
 432                                                gc_pos_alloc(c, NULL),
 433                                                BCH_BUCKET_MARK_GC);
 434
 435
 436
 437                 for (j = 0; j < RESERVE_NR; j++)
 438                         fifo_for_each_entry(i, &ca->free[j], iter)
 439                                 bch2_mark_alloc_bucket(c, ca, i, true,
 440                                                        gc_pos_alloc(c, NULL),
 441                                                        BCH_BUCKET_MARK_GC);
 442         }
 443
 444         spin_unlock(&c->freelist_lock);
 445
 446         for (ob = c->open_buckets;
 447              ob < c->open_buckets + ARRAY_SIZE(c->open_buckets);
 448              ob++) {
 449                 spin_lock(&ob->lock);
 450                 if (ob->valid) {
 451                         gc_pos_set(c, gc_pos_alloc(c, ob));
 452                         ca = bch_dev_bkey_exists(c, ob->ptr.dev);
 453                         bch2_mark_alloc_bucket(c, ca, PTR_BUCKET_NR(ca, &ob->ptr), true,
 454                                                gc_pos_alloc(c, ob),
 455                                                BCH_BUCKET_MARK_GC);
 456                 }
 457                 spin_unlock(&ob->lock);
 458         }
 459
 460         percpu_up_read_preempt_enable(&c->mark_lock);
 461 }
 462
 463 static void bch2_gc_free(struct bch_fs *c)
 464 {
 465         struct bch_dev *ca;
 466         unsigned i;
 467
 468         genradix_free(&c->stripes[1]);
 469
 470         for_each_member_device(ca, c, i) {
 471                 kvpfree(rcu_dereference_protected(ca->buckets[1], 1),
 472                         sizeof(struct bucket_array) +
 473                         ca->mi.nbuckets * sizeof(struct bucket));
 474                 ca->buckets[1] = NULL;
 475
 476                 free_percpu(ca->usage[1]);
 477                 ca->usage[1] = NULL;
 478         }
 479
 480         free_percpu(c->usage[1]);
 481         c->usage[1] = NULL;
 482 }
 483
 484 static int bch2_gc_done(struct bch_fs *c,
 485                         bool initial, bool metadata_only)
 486 {
 487         struct bch_dev *ca;
 488         bool verify = !metadata_only &&
 489                 (!initial ||
 490                  (c->sb.compat & (1ULL << BCH_COMPAT_FEAT_ALLOC_INFO)));
 491         unsigned i;
 492         int ret = 0;
 493
 494 #define copy_field(_f, _msg, ...)                                       \
 495         if (dst->_f != src->_f) {                                       \
 496                 if (verify)                                             \
 497                         fsck_err(c, _msg ": got %llu, should be %llu"   \
 498                                 , ##__VA_ARGS__, dst->_f, src->_f);     \
 499                 dst->_f = src->_f;                                      \
 500         }
 501 #define copy_stripe_field(_f, _msg, ...)                                \
 502         if (dst->_f != src->_f) {                                       \
 503                 if (verify)                                             \
 504                         fsck_err(c, "stripe %zu has wrong "_msg         \
 505                                 ": got %u, should be %u",               \
 506                                 dst_iter.pos, ##__VA_ARGS__,            \
 507                                 dst->_f, src->_f);                      \
 508                 dst->_f = src->_f;                                      \
 509                 dst->dirty = true;                                      \
 510         }
 511 #define copy_bucket_field(_f)                                           \
 512         if (dst->b[b].mark._f != src->b[b].mark._f) {                   \
 513                 if (verify)                                             \
 514                         fsck_err(c, "dev %u bucket %zu has wrong " #_f  \
 515                                 ": got %u, should be %u", i, b,         \
 516                                 dst->b[b].mark._f, src->b[b].mark._f);  \
 517                 dst->b[b]._mark._f = src->b[b].mark._f;                 \
 518                 dst->b[b]._mark.dirty = true;                           \
 519         }
 520 #define copy_dev_field(_f, _msg, ...)                                   \
 521         copy_field(_f, "dev %u has wrong " _msg, i, ##__VA_ARGS__)
 522 #define copy_fs_field(_f, _msg, ...)                                    \
 523         copy_field(_f, "fs has wrong " _msg, ##__VA_ARGS__)
 524
 525         if (!metadata_only) {
 526                 struct genradix_iter dst_iter = genradix_iter_init(&c->stripes[0], 0);
 527                 struct genradix_iter src_iter = genradix_iter_init(&c->stripes[1], 0);
 528                 struct stripe *dst, *src;
 529                 unsigned i;
 530
 531                 c->ec_stripes_heap.used = 0;
 532
 533                 while ((dst = genradix_iter_peek(&dst_iter, &c->stripes[0])) &&
 534                        (src = genradix_iter_peek(&src_iter, &c->stripes[1]))) {
 535                         BUG_ON(src_iter.pos != dst_iter.pos);
 536
 537                         copy_stripe_field(alive,        "alive");
 538                         copy_stripe_field(sectors,      "sectors");
 539                         copy_stripe_field(algorithm,    "algorithm");
 540                         copy_stripe_field(nr_blocks,    "nr_blocks");
 541                         copy_stripe_field(nr_redundant, "nr_redundant");
 542                         copy_stripe_field(blocks_nonempty,
 543                                           "blocks_nonempty");
 544
 545                         for (i = 0; i < ARRAY_SIZE(dst->block_sectors); i++)
 546                                 copy_stripe_field(block_sectors[i],
 547                                                   "block_sectors[%u]", i);
 548
 549                         if (dst->alive)
 550                                 bch2_stripes_heap_insert(c, dst, dst_iter.pos);
 551
 552                         genradix_iter_advance(&dst_iter, &c->stripes[0]);
 553                         genradix_iter_advance(&src_iter, &c->stripes[1]);
 554                 }
 555         }
 556
 557         for_each_member_device(ca, c, i) {
 558                 struct bucket_array *dst = __bucket_array(ca, 0);
 559                 struct bucket_array *src = __bucket_array(ca, 1);
 560                 size_t b;
 561
 562                 for (b = 0; b < src->nbuckets; b++) {
 563                         copy_bucket_field(gen);
 564                         copy_bucket_field(data_type);
 565                         copy_bucket_field(owned_by_allocator);
 566                         copy_bucket_field(stripe);
 567                         copy_bucket_field(dirty_sectors);
 568                         copy_bucket_field(cached_sectors);
 569
 570                         if (dst->b[b].oldest_gen != src->b[b].oldest_gen) {
 571                                 dst->b[b].oldest_gen = src->b[b].oldest_gen;
 572                                 dst->b[b]._mark.dirty = true;
 573                         }
 574                 }
 575         };
 576
 577         bch2_dev_usage_from_buckets(c);
 578
 579         {
 580                 unsigned nr = fs_usage_u64s(c);
 581                 struct bch_fs_usage *dst = (void *)
 582                         bch2_acc_percpu_u64s((void *) c->usage[0], nr);
 583                 struct bch_fs_usage *src = (void *)
 584                         bch2_acc_percpu_u64s((void *) c->usage[1], nr);
 585
 586                 copy_fs_field(hidden,           "hidden");
 587                 copy_fs_field(btree,            "btree");
 588
 589                 if (!metadata_only) {
 590                         copy_fs_field(data,     "data");
 591                         copy_fs_field(cached,   "cached");
 592                         copy_fs_field(reserved, "reserved");
 593                         copy_fs_field(nr_inodes,"nr_inodes");
 594
 595                         for (i = 0; i < BCH_REPLICAS_MAX; i++)
 596                                 copy_fs_field(persistent_reserved[i],
 597                                               "persistent_reserved[%i]", i);
 598                 }
 599
 600                 for (i = 0; i < c->replicas.nr; i++) {
 601                         struct bch_replicas_entry *e =
 602                                 cpu_replicas_entry(&c->replicas, i);
 603                         char buf[80];
 604
 605                         if (metadata_only &&
 606                             (e->data_type == BCH_DATA_USER ||
 607                              e->data_type == BCH_DATA_CACHED))
 608                                 continue;
 609
 610                         bch2_replicas_entry_to_text(&PBUF(buf), e);
 611
 612                         copy_fs_field(replicas[i], "%s", buf);
 613                 }
 614         }
 615
 616 #undef copy_fs_field
 617 #undef copy_dev_field
 618 #undef copy_bucket_field
 619 #undef copy_stripe_field
 620 #undef copy_field
 621 fsck_err:
 622         return ret;
 623 }
 624
 625 static int bch2_gc_start(struct bch_fs *c,
 626                          bool metadata_only)
 627 {
 628         struct bch_dev *ca;
 629         unsigned i;
 630
 631         /*
 632          * indicate to stripe code that we need to allocate for the gc stripes
 633          * radix tree, too
 634          */
 635         gc_pos_set(c, gc_phase(GC_PHASE_START));
 636
 637         BUG_ON(c->usage[1]);
 638
 639         c->usage[1] = __alloc_percpu_gfp(fs_usage_u64s(c) * sizeof(u64),
 640                                          sizeof(u64), GFP_KERNEL);
 641         if (!c->usage[1])
 642                 return -ENOMEM;
 643
 644         for_each_member_device(ca, c, i) {
 645                 BUG_ON(ca->buckets[1]);
 646                 BUG_ON(ca->usage[1]);
 647
 648                 ca->buckets[1] = kvpmalloc(sizeof(struct bucket_array) +
 649                                 ca->mi.nbuckets * sizeof(struct bucket),
 650                                 GFP_KERNEL|__GFP_ZERO);
 651                 if (!ca->buckets[1]) {
 652                         percpu_ref_put(&ca->ref);
 653                         return -ENOMEM;
 654                 }
 655
 656                 ca->usage[1] = alloc_percpu(struct bch_dev_usage);
 657                 if (!ca->usage[1]) {
 658                         percpu_ref_put(&ca->ref);
 659                         return -ENOMEM;
 660                 }
 661         }
 662
 663         for_each_member_device(ca, c, i) {
 664                 struct bucket_array *dst = __bucket_array(ca, 1);
 665                 struct bucket_array *src = __bucket_array(ca, 0);
 666                 size_t b;
 667
 668                 dst->first_bucket       = src->first_bucket;
 669                 dst->nbuckets           = src->nbuckets;
 670
 671                 for (b = 0; b < src->nbuckets; b++) {
 672                         struct bucket *d = &dst->b[b];
 673                         struct bucket *s = &src->b[b];
 674
 675                         d->_mark.gen = dst->b[b].oldest_gen = s->mark.gen;
 676                         d->gen_valid = s->gen_valid;
 677
 678                         if (metadata_only &&
 679                             (s->mark.data_type == BCH_DATA_USER ||
 680                              s->mark.data_type == BCH_DATA_CACHED)) {
 681                                 d->_mark = s->mark;
 682                                 d->_mark.owned_by_allocator = 0;
 683                         }
 684                 }
 685         };
 686
 687         return bch2_ec_mem_alloc(c, true);
 688 }
 689
 690 /**
 691  * bch2_gc - walk _all_ references to buckets, and recompute them:
 692  *
 693  * Order matters here:
 694  *  - Concurrent GC relies on the fact that we have a total ordering for
 695  *    everything that GC walks - see  gc_will_visit_node(),
 696  *    gc_will_visit_root()
 697  *
 698  *  - also, references move around in the course of index updates and
 699  *    various other crap: everything needs to agree on the ordering
 700  *    references are allowed to move around in - e.g., we're allowed to
 701  *    start with a reference owned by an open_bucket (the allocator) and
 702  *    move it to the btree, but not the reverse.
 703  *
 704  *    This is necessary to ensure that gc doesn't miss references that
 705  *    move around - if references move backwards in the ordering GC
 706  *    uses, GC could skip past them
 707  */
 708 int bch2_gc(struct bch_fs *c, struct list_head *journal,
 709             bool initial, bool metadata_only)
 710 {
 711         struct bch_dev *ca;
 712         u64 start_time = local_clock();
 713         unsigned i, iter = 0;
 714         int ret;
 715
 716         trace_gc_start(c);
 717
 718         down_write(&c->gc_lock);
 719 again:
 720         percpu_down_write(&c->mark_lock);
 721         ret = bch2_gc_start(c, metadata_only);
 722         percpu_up_write(&c->mark_lock);
 723
 724         if (ret)
 725                 goto out;
 726
 727         bch2_mark_superblocks(c);
 728
 729         ret = bch2_gc_btrees(c, journal, initial, metadata_only);
 730         if (ret)
 731                 goto out;
 732
 733         bch2_mark_pending_btree_node_frees(c);
 734         bch2_mark_allocator_buckets(c);
 735
 736         c->gc_count++;
 737 out:
 738         if (!ret &&
 739             (test_bit(BCH_FS_FIXED_GENS, &c->flags) ||
 740              (!iter && test_restart_gc(c)))) {
 741                 /*
 742                  * XXX: make sure gens we fixed got saved
 743                  */
 744                 if (iter++ <= 2) {
 745                         bch_info(c, "Fixed gens, restarting mark and sweep:");
 746                         clear_bit(BCH_FS_FIXED_GENS, &c->flags);
 747                         __gc_pos_set(c, gc_phase(GC_PHASE_NOT_RUNNING));
 748
 749                         percpu_down_write(&c->mark_lock);
 750                         bch2_gc_free(c);
 751                         percpu_up_write(&c->mark_lock);
 752
 753                         goto again;
 754                 }
 755
 756                 bch_info(c, "Unable to fix bucket gens, looping");
 757                 ret = -EINVAL;
 758         }
 759
 760         percpu_down_write(&c->mark_lock);
 761
 762         if (!ret)
 763                 ret = bch2_gc_done(c, initial, metadata_only);
 764
 765         /* Indicates that gc is no longer in progress: */
 766         __gc_pos_set(c, gc_phase(GC_PHASE_NOT_RUNNING));
 767
 768         bch2_gc_free(c);
 769         percpu_up_write(&c->mark_lock);
 770
 771         up_write(&c->gc_lock);
 772
 773         trace_gc_end(c);
 774         bch2_time_stats_update(&c->times[BCH_TIME_btree_gc], start_time);
 775
 776         /*
 777          * Wake up allocator in case it was waiting for buckets
 778          * because of not being able to inc gens
 779          */
 780         for_each_member_device(ca, c, i)
 781                 bch2_wake_allocator(ca);
 782
 783         /*
 784          * At startup, allocations can happen directly instead of via the
 785          * allocator thread - issue wakeup in case they blocked on gc_lock:
 786          */
 787         closure_wake_up(&c->freelist_wait);
 788         return ret;
 789 }
 790
 791 /* Btree coalescing */
 792
 793 static void recalc_packed_keys(struct btree *b)
 794 {
 795         struct bset *i = btree_bset_first(b);
 796         struct bkey_packed *k;
 797
 798         memset(&b->nr, 0, sizeof(b->nr));
 799
 800         BUG_ON(b->nsets != 1);
 801
 802         vstruct_for_each(i, k)
 803                 btree_keys_account_key_add(&b->nr, 0, k);
 804 }
 805
 806 static void bch2_coalesce_nodes(struct bch_fs *c, struct btree_iter *iter,
 807                                 struct btree *old_nodes[GC_MERGE_NODES])
 808 {
 809         struct btree *parent = btree_node_parent(iter, old_nodes[0]);
 810         unsigned i, nr_old_nodes, nr_new_nodes, u64s = 0;
 811         unsigned blocks = btree_blocks(c) * 2 / 3;
 812         struct btree *new_nodes[GC_MERGE_NODES];
 813         struct btree_update *as;
 814         struct keylist keylist;
 815         struct bkey_format_state format_state;
 816         struct bkey_format new_format;
 817
 818         memset(new_nodes, 0, sizeof(new_nodes));
 819         bch2_keylist_init(&keylist, NULL);
 820
 821         /* Count keys that are not deleted */
 822         for (i = 0; i < GC_MERGE_NODES && old_nodes[i]; i++)
 823                 u64s += old_nodes[i]->nr.live_u64s;
 824
 825         nr_old_nodes = nr_new_nodes = i;
 826
 827         /* Check if all keys in @old_nodes could fit in one fewer node */
 828         if (nr_old_nodes <= 1 ||
 829             __vstruct_blocks(struct btree_node, c->block_bits,
 830                              DIV_ROUND_UP(u64s, nr_old_nodes - 1)) > blocks)
 831                 return;
 832
 833         /* Find a format that all keys in @old_nodes can pack into */
 834         bch2_bkey_format_init(&format_state);
 835
 836         for (i = 0; i < nr_old_nodes; i++)
 837                 __bch2_btree_calc_format(&format_state, old_nodes[i]);
 838
 839         new_format = bch2_bkey_format_done(&format_state);
 840
 841         /* Check if repacking would make any nodes too big to fit */
 842         for (i = 0; i < nr_old_nodes; i++)
 843                 if (!bch2_btree_node_format_fits(c, old_nodes[i], &new_format)) {
 844                         trace_btree_gc_coalesce_fail(c,
 845                                         BTREE_GC_COALESCE_FAIL_FORMAT_FITS);
 846                         return;
 847                 }
 848
 849         if (bch2_keylist_realloc(&keylist, NULL, 0,
 850                         (BKEY_U64s + BKEY_EXTENT_U64s_MAX) * nr_old_nodes)) {
 851                 trace_btree_gc_coalesce_fail(c,
 852                                 BTREE_GC_COALESCE_FAIL_KEYLIST_REALLOC);
 853                 return;
 854         }
 855
 856         as = bch2_btree_update_start(c, iter->btree_id,
 857                         btree_update_reserve_required(c, parent) + nr_old_nodes,
 858                         BTREE_INSERT_NOFAIL|
 859                         BTREE_INSERT_USE_RESERVE,
 860                         NULL);
 861         if (IS_ERR(as)) {
 862                 trace_btree_gc_coalesce_fail(c,
 863                                 BTREE_GC_COALESCE_FAIL_RESERVE_GET);
 864                 bch2_keylist_free(&keylist, NULL);
 865                 return;
 866         }
 867
 868         trace_btree_gc_coalesce(c, old_nodes[0]);
 869
 870         for (i = 0; i < nr_old_nodes; i++)
 871                 bch2_btree_interior_update_will_free_node(as, old_nodes[i]);
 872
 873         /* Repack everything with @new_format and sort down to one bset */
 874         for (i = 0; i < nr_old_nodes; i++)
 875                 new_nodes[i] =
 876                         __bch2_btree_node_alloc_replacement(as, old_nodes[i],
 877                                                             new_format);
 878
 879         /*
 880          * Conceptually we concatenate the nodes together and slice them
 881          * up at different boundaries.
 882          */
 883         for (i = nr_new_nodes - 1; i > 0; --i) {
 884                 struct btree *n1 = new_nodes[i];
 885                 struct btree *n2 = new_nodes[i - 1];
 886
 887                 struct bset *s1 = btree_bset_first(n1);
 888                 struct bset *s2 = btree_bset_first(n2);
 889                 struct bkey_packed *k, *last = NULL;
 890
 891                 /* Calculate how many keys from @n2 we could fit inside @n1 */
 892                 u64s = 0;
 893
 894                 for (k = s2->start;
 895                      k < vstruct_last(s2) &&
 896                      vstruct_blocks_plus(n1->data, c->block_bits,
 897                                          u64s + k->u64s) <= blocks;
 898                      k = bkey_next(k)) {
 899                         last = k;
 900                         u64s += k->u64s;
 901                 }
 902
 903                 if (u64s == le16_to_cpu(s2->u64s)) {
 904                         /* n2 fits entirely in n1 */
 905                         n1->key.k.p = n1->data->max_key = n2->data->max_key;
 906
 907                         memcpy_u64s(vstruct_last(s1),
 908                                     s2->start,
 909                                     le16_to_cpu(s2->u64s));
 910                         le16_add_cpu(&s1->u64s, le16_to_cpu(s2->u64s));
 911
 912                         set_btree_bset_end(n1, n1->set);
 913
 914                         six_unlock_write(&n2->lock);
 915                         bch2_btree_node_free_never_inserted(c, n2);
 916                         six_unlock_intent(&n2->lock);
 917
 918                         memmove(new_nodes + i - 1,
 919                                 new_nodes + i,
 920                                 sizeof(new_nodes[0]) * (nr_new_nodes - i));
 921                         new_nodes[--nr_new_nodes] = NULL;
 922                 } else if (u64s) {
 923                         /* move part of n2 into n1 */
 924                         n1->key.k.p = n1->data->max_key =
 925                                 bkey_unpack_pos(n1, last);
 926
 927                         n2->data->min_key =
 928                                 btree_type_successor(iter->btree_id,
 929                                                      n1->data->max_key);
 930
 931                         memcpy_u64s(vstruct_last(s1),
 932                                     s2->start, u64s);
 933                         le16_add_cpu(&s1->u64s, u64s);
 934
 935                         memmove(s2->start,
 936                                 vstruct_idx(s2, u64s),
 937                                 (le16_to_cpu(s2->u64s) - u64s) * sizeof(u64));
 938                         s2->u64s = cpu_to_le16(le16_to_cpu(s2->u64s) - u64s);
 939
 940                         set_btree_bset_end(n1, n1->set);
 941                         set_btree_bset_end(n2, n2->set);
 942                 }
 943         }
 944
 945         for (i = 0; i < nr_new_nodes; i++) {
 946                 struct btree *n = new_nodes[i];
 947
 948                 recalc_packed_keys(n);
 949                 btree_node_reset_sib_u64s(n);
 950
 951                 bch2_btree_build_aux_trees(n);
 952                 six_unlock_write(&n->lock);
 953
 954                 bch2_btree_node_write(c, n, SIX_LOCK_intent);
 955         }
 956
 957         /*
 958          * The keys for the old nodes get deleted. We don't want to insert keys
 959          * that compare equal to the keys for the new nodes we'll also be
 960          * inserting - we can't because keys on a keylist must be strictly
 961          * greater than the previous keys, and we also don't need to since the
 962          * key for the new node will serve the same purpose (overwriting the key
 963          * for the old node).
 964          */
 965         for (i = 0; i < nr_old_nodes; i++) {
 966                 struct bkey_i delete;
 967                 unsigned j;
 968
 969                 for (j = 0; j < nr_new_nodes; j++)
 970                         if (!bkey_cmp(old_nodes[i]->key.k.p,
 971                                       new_nodes[j]->key.k.p))
 972                                 goto next;
 973
 974                 bkey_init(&delete.k);
 975                 delete.k.p = old_nodes[i]->key.k.p;
 976                 bch2_keylist_add_in_order(&keylist, &delete);
 977 next:
 978                 i = i;
 979         }
 980
 981         /*
 982          * Keys for the new nodes get inserted: bch2_btree_insert_keys() only
 983          * does the lookup once and thus expects the keys to be in sorted order
 984          * so we have to make sure the new keys are correctly ordered with
 985          * respect to the deleted keys added in the previous loop
 986          */
 987         for (i = 0; i < nr_new_nodes; i++)
 988                 bch2_keylist_add_in_order(&keylist, &new_nodes[i]->key);
 989
 990         /* Insert the newly coalesced nodes */
 991         bch2_btree_insert_node(as, parent, iter, &keylist, 0);
 992
 993         BUG_ON(!bch2_keylist_empty(&keylist));
 994
 995         BUG_ON(iter->l[old_nodes[0]->level].b != old_nodes[0]);
 996
 997         bch2_btree_iter_node_replace(iter, new_nodes[0]);
 998
 999         for (i = 0; i < nr_new_nodes; i++)
1000                 bch2_open_buckets_put(c, &new_nodes[i]->ob);
1001
1002         /* Free the old nodes and update our sliding window */
1003         for (i = 0; i < nr_old_nodes; i++) {
1004                 bch2_btree_node_free_inmem(c, old_nodes[i], iter);
1005
1006                 /*
1007                  * the index update might have triggered a split, in which case
1008                  * the nodes we coalesced - the new nodes we just created -
1009                  * might not be sibling nodes anymore - don't add them to the
1010                  * sliding window (except the first):
1011                  */
1012                 if (!i) {
1013                         old_nodes[i] = new_nodes[i];
1014                 } else {
1015                         old_nodes[i] = NULL;
1016                         if (new_nodes[i])
1017                                 six_unlock_intent(&new_nodes[i]->lock);
1018                 }
1019         }
1020
1021         bch2_btree_update_done(as);
1022         bch2_keylist_free(&keylist, NULL);
1023 }
1024
1025 static int bch2_coalesce_btree(struct bch_fs *c, enum btree_id btree_id)
1026 {
1027         struct btree_trans trans;
1028         struct btree_iter *iter;
1029         struct btree *b;
1030         bool kthread = (current->flags & PF_KTHREAD) != 0;
1031         unsigned i;
1032
1033         /* Sliding window of adjacent btree nodes */
1034         struct btree *merge[GC_MERGE_NODES];
1035         u32 lock_seq[GC_MERGE_NODES];
1036
1037         bch2_trans_init(&trans, c);
1038
1039         /*
1040          * XXX: We don't have a good way of positively matching on sibling nodes
1041          * that have the same parent - this code works by handling the cases
1042          * where they might not have the same parent, and is thus fragile. Ugh.
1043          *
1044          * Perhaps redo this to use multiple linked iterators?
1045          */
1046         memset(merge, 0, sizeof(merge));
1047
1048         __for_each_btree_node(&trans, iter, btree_id, POS_MIN,
1049                               BTREE_MAX_DEPTH, 0,
1050                               BTREE_ITER_PREFETCH, b) {
1051                 memmove(merge + 1, merge,
1052                         sizeof(merge) - sizeof(merge[0]));
1053                 memmove(lock_seq + 1, lock_seq,
1054                         sizeof(lock_seq) - sizeof(lock_seq[0]));
1055
1056                 merge[0] = b;
1057
1058                 for (i = 1; i < GC_MERGE_NODES; i++) {
1059                         if (!merge[i] ||
1060                             !six_relock_intent(&merge[i]->lock, lock_seq[i]))
1061                                 break;
1062
1063                         if (merge[i]->level != merge[0]->level) {
1064                                 six_unlock_intent(&merge[i]->lock);
1065                                 break;
1066                         }
1067                 }
1068                 memset(merge + i, 0, (GC_MERGE_NODES - i) * sizeof(merge[0]));
1069
1070                 bch2_coalesce_nodes(c, iter, merge);
1071
1072                 for (i = 1; i < GC_MERGE_NODES && merge[i]; i++) {
1073                         lock_seq[i] = merge[i]->lock.state.seq;
1074                         six_unlock_intent(&merge[i]->lock);
1075                 }
1076
1077                 lock_seq[0] = merge[0]->lock.state.seq;
1078
1079                 if (kthread && kthread_should_stop()) {
1080                         bch2_trans_exit(&trans);
1081                         return -ESHUTDOWN;
1082                 }
1083
1084                 bch2_trans_cond_resched(&trans);
1085
1086                 /*
1087                  * If the parent node wasn't relocked, it might have been split
1088                  * and the nodes in our sliding window might not have the same
1089                  * parent anymore - blow away the sliding window:
1090                  */
1091                 if (btree_iter_node(iter, iter->level + 1) &&
1092                     !btree_node_intent_locked(iter, iter->level + 1))
1093                         memset(merge + 1, 0,
1094                                (GC_MERGE_NODES - 1) * sizeof(merge[0]));
1095         }
1096         return bch2_trans_exit(&trans);
1097 }
1098
1099 /**
1100  * bch_coalesce - coalesce adjacent nodes with low occupancy
1101  */
1102 void bch2_coalesce(struct bch_fs *c)
1103 {
1104         enum btree_id id;
1105
1106         down_read(&c->gc_lock);
1107         trace_gc_coalesce_start(c);
1108
1109         for (id = 0; id < BTREE_ID_NR; id++) {
1110                 int ret = c->btree_roots[id].b
1111                         ? bch2_coalesce_btree(c, id)
1112                         : 0;
1113
1114                 if (ret) {
1115                         if (ret != -ESHUTDOWN)
1116                                 bch_err(c, "btree coalescing failed: %d", ret);
1117                         return;
1118                 }
1119         }
1120
1121         trace_gc_coalesce_end(c);
1122         up_read(&c->gc_lock);
1123 }
1124
1125 static int bch2_gc_thread(void *arg)
1126 {
1127         struct bch_fs *c = arg;
1128         struct io_clock *clock = &c->io_clock[WRITE];
1129         unsigned long last = atomic_long_read(&clock->now);
1130         unsigned last_kick = atomic_read(&c->kick_gc);
1131         int ret;
1132
1133         set_freezable();
1134
1135         while (1) {
1136                 while (1) {
1137                         set_current_state(TASK_INTERRUPTIBLE);
1138
1139                         if (kthread_should_stop()) {
1140                                 __set_current_state(TASK_RUNNING);
1141                                 return 0;
1142                         }
1143
1144                         if (atomic_read(&c->kick_gc) != last_kick)
1145                                 break;
1146
1147                         if (c->btree_gc_periodic) {
1148                                 unsigned long next = last + c->capacity / 16;
1149
1150                                 if (atomic_long_read(&clock->now) >= next)
1151                                         break;
1152
1153                                 bch2_io_clock_schedule_timeout(clock, next);
1154                         } else {
1155                                 schedule();
1156                         }
1157
1158                         try_to_freeze();
1159                 }
1160                 __set_current_state(TASK_RUNNING);
1161
1162                 last = atomic_long_read(&clock->now);
1163                 last_kick = atomic_read(&c->kick_gc);
1164
1165                 ret = bch2_gc(c, NULL, false, false);
1166                 if (ret)
1167                         bch_err(c, "btree gc failed: %i", ret);
1168
1169                 debug_check_no_locks_held();
1170         }
1171
1172         return 0;
1173 }
1174
1175 void bch2_gc_thread_stop(struct bch_fs *c)
1176 {
1177         struct task_struct *p;
1178
1179         p = c->gc_thread;
1180         c->gc_thread = NULL;
1181
1182         if (p) {
1183                 kthread_stop(p);
1184                 put_task_struct(p);
1185         }
1186 }
1187
1188 int bch2_gc_thread_start(struct bch_fs *c)
1189 {
1190         struct task_struct *p;
1191
1192         BUG_ON(c->gc_thread);
1193
1194         p = kthread_create(bch2_gc_thread, c, "bch_gc");
1195         if (IS_ERR(p))
1196                 return PTR_ERR(p);
1197
1198         get_task_struct(p);
1199         c->gc_thread = p;
1200         wake_up_process(p);
1201         return 0;
1202 }