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

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 /* erasure coding */
   4
   5 #include "bcachefs.h"
   6 #include "alloc_foreground.h"
   7 #include "bkey_buf.h"
   8 #include "bset.h"
   9 #include "btree_gc.h"
  10 #include "btree_update.h"
  11 #include "buckets.h"
  12 #include "disk_groups.h"
  13 #include "ec.h"
  14 #include "error.h"
  15 #include "io.h"
  16 #include "keylist.h"
  17 #include "recovery.h"
  18 #include "replicas.h"
  19 #include "super-io.h"
  20 #include "util.h"
  21
  22 #include <linux/sort.h>
  23
  24 #ifdef __KERNEL__
  25
  26 #include <linux/raid/pq.h>
  27 #include <linux/raid/xor.h>
  28
  29 static void raid5_recov(unsigned disks, unsigned failed_idx,
  30                         size_t size, void **data)
  31 {
  32         unsigned i = 2, nr;
  33
  34         BUG_ON(failed_idx >= disks);
  35
  36         swap(data[0], data[failed_idx]);
  37         memcpy(data[0], data[1], size);
  38
  39         while (i < disks) {
  40                 nr = min_t(unsigned, disks - i, MAX_XOR_BLOCKS);
  41                 xor_blocks(nr, size, data[0], data + i);
  42                 i += nr;
  43         }
  44
  45         swap(data[0], data[failed_idx]);
  46 }
  47
  48 static void raid_gen(int nd, int np, size_t size, void **v)
  49 {
  50         if (np >= 1)
  51                 raid5_recov(nd + np, nd, size, v);
  52         if (np >= 2)
  53                 raid6_call.gen_syndrome(nd + np, size, v);
  54         BUG_ON(np > 2);
  55 }
  56
  57 static void raid_rec(int nr, int *ir, int nd, int np, size_t size, void **v)
  58 {
  59         switch (nr) {
  60         case 0:
  61                 break;
  62         case 1:
  63                 if (ir[0] < nd + 1)
  64                         raid5_recov(nd + 1, ir[0], size, v);
  65                 else
  66                         raid6_call.gen_syndrome(nd + np, size, v);
  67                 break;
  68         case 2:
  69                 if (ir[1] < nd) {
  70                         /* data+data failure. */
  71                         raid6_2data_recov(nd + np, size, ir[0], ir[1], v);
  72                 } else if (ir[0] < nd) {
  73                         /* data + p/q failure */
  74
  75                         if (ir[1] == nd) /* data + p failure */
  76                                 raid6_datap_recov(nd + np, size, ir[0], v);
  77                         else { /* data + q failure */
  78                                 raid5_recov(nd + 1, ir[0], size, v);
  79                                 raid6_call.gen_syndrome(nd + np, size, v);
  80                         }
  81                 } else {
  82                         raid_gen(nd, np, size, v);
  83                 }
  84                 break;
  85         default:
  86                 BUG();
  87         }
  88 }
  89
  90 #else
  91
  92 #include <raid/raid.h>
  93
  94 #endif
  95
  96 struct ec_bio {
  97         struct bch_dev          *ca;
  98         struct ec_stripe_buf    *buf;
  99         size_t                  idx;
 100         struct bio              bio;
 101 };
 102
 103 /* Stripes btree keys: */
 104
 105 const char *bch2_stripe_invalid(const struct bch_fs *c, struct bkey_s_c k)
 106 {
 107         const struct bch_stripe *s = bkey_s_c_to_stripe(k).v;
 108
 109         if (!bkey_cmp(k.k->p, POS_MIN))
 110                 return "stripe at pos 0";
 111
 112         if (k.k->p.inode)
 113                 return "invalid stripe key";
 114
 115         if (bkey_val_bytes(k.k) < sizeof(*s))
 116                 return "incorrect value size";
 117
 118         if (bkey_val_bytes(k.k) < sizeof(*s) ||
 119             bkey_val_u64s(k.k) < stripe_val_u64s(s))
 120                 return "incorrect value size";
 121
 122         return bch2_bkey_ptrs_invalid(c, k);
 123 }
 124
 125 void bch2_stripe_to_text(struct printbuf *out, struct bch_fs *c,
 126                          struct bkey_s_c k)
 127 {
 128         const struct bch_stripe *s = bkey_s_c_to_stripe(k).v;
 129         unsigned i;
 130
 131         pr_buf(out, "algo %u sectors %u blocks %u:%u csum %u gran %u",
 132                s->algorithm,
 133                le16_to_cpu(s->sectors),
 134                s->nr_blocks - s->nr_redundant,
 135                s->nr_redundant,
 136                s->csum_type,
 137                1U << s->csum_granularity_bits);
 138
 139         for (i = 0; i < s->nr_blocks; i++)
 140                 pr_buf(out, " %u:%llu:%u", s->ptrs[i].dev,
 141                        (u64) s->ptrs[i].offset,
 142                        stripe_blockcount_get(s, i));
 143 }
 144
 145 /* returns blocknr in stripe that we matched: */
 146 static const struct bch_extent_ptr *bkey_matches_stripe(struct bch_stripe *s,
 147                                                 struct bkey_s_c k, unsigned *block)
 148 {
 149         struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
 150         const struct bch_extent_ptr *ptr;
 151         unsigned i, nr_data = s->nr_blocks - s->nr_redundant;
 152
 153         bkey_for_each_ptr(ptrs, ptr)
 154                 for (i = 0; i < nr_data; i++)
 155                         if (__bch2_ptr_matches_stripe(&s->ptrs[i], ptr,
 156                                                       le16_to_cpu(s->sectors))) {
 157                                 *block = i;
 158                                 return ptr;
 159                         }
 160
 161         return NULL;
 162 }
 163
 164 static bool extent_has_stripe_ptr(struct bkey_s_c k, u64 idx)
 165 {
 166         switch (k.k->type) {
 167         case KEY_TYPE_extent: {
 168                 struct bkey_s_c_extent e = bkey_s_c_to_extent(k);
 169                 const union bch_extent_entry *entry;
 170
 171                 extent_for_each_entry(e, entry)
 172                         if (extent_entry_type(entry) ==
 173                             BCH_EXTENT_ENTRY_stripe_ptr &&
 174                             entry->stripe_ptr.idx == idx)
 175                                 return true;
 176
 177                 break;
 178         }
 179         }
 180
 181         return false;
 182 }
 183
 184 /* Stripe bufs: */
 185
 186 static void ec_stripe_buf_exit(struct ec_stripe_buf *buf)
 187 {
 188         unsigned i;
 189
 190         for (i = 0; i < buf->key.v.nr_blocks; i++) {
 191                 kvpfree(buf->data[i], buf->size << 9);
 192                 buf->data[i] = NULL;
 193         }
 194 }
 195
 196 static int ec_stripe_buf_init(struct ec_stripe_buf *buf,
 197                                unsigned offset, unsigned size)
 198 {
 199         struct bch_stripe *v = &buf->key.v;
 200         unsigned csum_granularity = 1U << v->csum_granularity_bits;
 201         unsigned end = offset + size;
 202         unsigned i;
 203
 204         BUG_ON(end > le16_to_cpu(v->sectors));
 205
 206         offset  = round_down(offset, csum_granularity);
 207         end     = min_t(unsigned, le16_to_cpu(v->sectors),
 208                         round_up(end, csum_granularity));
 209
 210         buf->offset     = offset;
 211         buf->size       = end - offset;
 212
 213         memset(buf->valid, 0xFF, sizeof(buf->valid));
 214
 215         for (i = 0; i < buf->key.v.nr_blocks; i++) {
 216                 buf->data[i] = kvpmalloc(buf->size << 9, GFP_KERNEL);
 217                 if (!buf->data[i])
 218                         goto err;
 219         }
 220
 221         return 0;
 222 err:
 223         ec_stripe_buf_exit(buf);
 224         return -ENOMEM;
 225 }
 226
 227 /* Checksumming: */
 228
 229 static struct bch_csum ec_block_checksum(struct ec_stripe_buf *buf,
 230                                          unsigned block, unsigned offset)
 231 {
 232         struct bch_stripe *v = &buf->key.v;
 233         unsigned csum_granularity = 1 << v->csum_granularity_bits;
 234         unsigned end = buf->offset + buf->size;
 235         unsigned len = min(csum_granularity, end - offset);
 236
 237         BUG_ON(offset >= end);
 238         BUG_ON(offset <  buf->offset);
 239         BUG_ON(offset & (csum_granularity - 1));
 240         BUG_ON(offset + len != le16_to_cpu(v->sectors) &&
 241                (len & (csum_granularity - 1)));
 242
 243         return bch2_checksum(NULL, v->csum_type,
 244                              null_nonce(),
 245                              buf->data[block] + ((offset - buf->offset) << 9),
 246                              len << 9);
 247 }
 248
 249 static void ec_generate_checksums(struct ec_stripe_buf *buf)
 250 {
 251         struct bch_stripe *v = &buf->key.v;
 252         unsigned i, j, csums_per_device = stripe_csums_per_device(v);
 253
 254         if (!v->csum_type)
 255                 return;
 256
 257         BUG_ON(buf->offset);
 258         BUG_ON(buf->size != le16_to_cpu(v->sectors));
 259
 260         for (i = 0; i < v->nr_blocks; i++)
 261                 for (j = 0; j < csums_per_device; j++)
 262                         stripe_csum_set(v, i, j,
 263                                 ec_block_checksum(buf, i, j << v->csum_granularity_bits));
 264 }
 265
 266 static void ec_validate_checksums(struct bch_fs *c, struct ec_stripe_buf *buf)
 267 {
 268         struct bch_stripe *v = &buf->key.v;
 269         unsigned csum_granularity = 1 << v->csum_granularity_bits;
 270         unsigned i;
 271
 272         if (!v->csum_type)
 273                 return;
 274
 275         for (i = 0; i < v->nr_blocks; i++) {
 276                 unsigned offset = buf->offset;
 277                 unsigned end = buf->offset + buf->size;
 278
 279                 if (!test_bit(i, buf->valid))
 280                         continue;
 281
 282                 while (offset < end) {
 283                         unsigned j = offset >> v->csum_granularity_bits;
 284                         unsigned len = min(csum_granularity, end - offset);
 285                         struct bch_csum want = stripe_csum_get(v, i, j);
 286                         struct bch_csum got = ec_block_checksum(buf, i, offset);
 287
 288                         if (bch2_crc_cmp(want, got)) {
 289                                 char buf2[200];
 290
 291                                 bch2_bkey_val_to_text(&PBUF(buf2), c, bkey_i_to_s_c(&buf->key.k_i));
 292
 293                                 bch_err_ratelimited(c,
 294                                         "stripe checksum error for %ps at %u:%u: csum type %u, expected %llx got %llx\n%s",
 295                                         (void *) _RET_IP_, i, j, v->csum_type,
 296                                         want.lo, got.lo, buf2);
 297                                 clear_bit(i, buf->valid);
 298                                 break;
 299                         }
 300
 301                         offset += len;
 302                 }
 303         }
 304 }
 305
 306 /* Erasure coding: */
 307
 308 static void ec_generate_ec(struct ec_stripe_buf *buf)
 309 {
 310         struct bch_stripe *v = &buf->key.v;
 311         unsigned nr_data = v->nr_blocks - v->nr_redundant;
 312         unsigned bytes = le16_to_cpu(v->sectors) << 9;
 313
 314         raid_gen(nr_data, v->nr_redundant, bytes, buf->data);
 315 }
 316
 317 static unsigned ec_nr_failed(struct ec_stripe_buf *buf)
 318 {
 319         return buf->key.v.nr_blocks -
 320                 bitmap_weight(buf->valid, buf->key.v.nr_blocks);
 321 }
 322
 323 static int ec_do_recov(struct bch_fs *c, struct ec_stripe_buf *buf)
 324 {
 325         struct bch_stripe *v = &buf->key.v;
 326         unsigned i, failed[BCH_BKEY_PTRS_MAX], nr_failed = 0;
 327         unsigned nr_data = v->nr_blocks - v->nr_redundant;
 328         unsigned bytes = buf->size << 9;
 329
 330         if (ec_nr_failed(buf) > v->nr_redundant) {
 331                 bch_err_ratelimited(c,
 332                         "error doing reconstruct read: unable to read enough blocks");
 333                 return -1;
 334         }
 335
 336         for (i = 0; i < nr_data; i++)
 337                 if (!test_bit(i, buf->valid))
 338                         failed[nr_failed++] = i;
 339
 340         raid_rec(nr_failed, failed, nr_data, v->nr_redundant, bytes, buf->data);
 341         return 0;
 342 }
 343
 344 /* IO: */
 345
 346 static void ec_block_endio(struct bio *bio)
 347 {
 348         struct ec_bio *ec_bio = container_of(bio, struct ec_bio, bio);
 349         struct bch_stripe *v = &ec_bio->buf->key.v;
 350         struct bch_extent_ptr *ptr = &v->ptrs[ec_bio->idx];
 351         struct bch_dev *ca = ec_bio->ca;
 352         struct closure *cl = bio->bi_private;
 353
 354         if (bch2_dev_io_err_on(bio->bi_status, ca, "erasure coding %s error: %s",
 355                                bio_data_dir(bio) ? "write" : "read",
 356                                bch2_blk_status_to_str(bio->bi_status)))
 357                 clear_bit(ec_bio->idx, ec_bio->buf->valid);
 358
 359         if (ptr_stale(ca, ptr)) {
 360                 bch_err_ratelimited(ca->fs,
 361                                     "error %s stripe: stale pointer after io",
 362                                     bio_data_dir(bio) == READ ? "reading from" : "writing to");
 363                 clear_bit(ec_bio->idx, ec_bio->buf->valid);
 364         }
 365
 366         bio_put(&ec_bio->bio);
 367         percpu_ref_put(&ca->io_ref);
 368         closure_put(cl);
 369 }
 370
 371 static void ec_block_io(struct bch_fs *c, struct ec_stripe_buf *buf,
 372                         unsigned rw, unsigned idx, struct closure *cl)
 373 {
 374         struct bch_stripe *v = &buf->key.v;
 375         unsigned offset = 0, bytes = buf->size << 9;
 376         struct bch_extent_ptr *ptr = &v->ptrs[idx];
 377         struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
 378         enum bch_data_type data_type = idx < buf->key.v.nr_blocks - buf->key.v.nr_redundant
 379                 ? BCH_DATA_user
 380                 : BCH_DATA_parity;
 381
 382         if (ptr_stale(ca, ptr)) {
 383                 bch_err_ratelimited(c,
 384                                     "error %s stripe: stale pointer",
 385                                     rw == READ ? "reading from" : "writing to");
 386                 clear_bit(idx, buf->valid);
 387                 return;
 388         }
 389
 390         if (!bch2_dev_get_ioref(ca, rw)) {
 391                 clear_bit(idx, buf->valid);
 392                 return;
 393         }
 394
 395         this_cpu_add(ca->io_done->sectors[rw][data_type], buf->size);
 396
 397         while (offset < bytes) {
 398                 unsigned nr_iovecs = min_t(size_t, BIO_MAX_VECS,
 399                                            DIV_ROUND_UP(bytes, PAGE_SIZE));
 400                 unsigned b = min_t(size_t, bytes - offset,
 401                                    nr_iovecs << PAGE_SHIFT);
 402                 struct ec_bio *ec_bio;
 403
 404                 ec_bio = container_of(bio_alloc_bioset(GFP_KERNEL, nr_iovecs,
 405                                                        &c->ec_bioset),
 406                                       struct ec_bio, bio);
 407
 408                 ec_bio->ca                      = ca;
 409                 ec_bio->buf                     = buf;
 410                 ec_bio->idx                     = idx;
 411
 412                 bio_set_dev(&ec_bio->bio, ca->disk_sb.bdev);
 413                 bio_set_op_attrs(&ec_bio->bio, rw, 0);
 414
 415                 ec_bio->bio.bi_iter.bi_sector   = ptr->offset + buf->offset + (offset >> 9);
 416                 ec_bio->bio.bi_end_io           = ec_block_endio;
 417                 ec_bio->bio.bi_private          = cl;
 418
 419                 bch2_bio_map(&ec_bio->bio, buf->data[idx] + offset, b);
 420
 421                 closure_get(cl);
 422                 percpu_ref_get(&ca->io_ref);
 423
 424                 submit_bio(&ec_bio->bio);
 425
 426                 offset += b;
 427         }
 428
 429         percpu_ref_put(&ca->io_ref);
 430 }
 431
 432 static int get_stripe_key(struct bch_fs *c, u64 idx, struct ec_stripe_buf *stripe)
 433 {
 434         struct btree_trans trans;
 435         struct btree_iter iter;
 436         struct bkey_s_c k;
 437         int ret;
 438
 439         bch2_trans_init(&trans, c, 0, 0);
 440         bch2_trans_iter_init(&trans, &iter, BTREE_ID_stripes,
 441                              POS(0, idx), BTREE_ITER_SLOTS);
 442         k = bch2_btree_iter_peek_slot(&iter);
 443         ret = bkey_err(k);
 444         if (ret)
 445                 goto err;
 446         if (k.k->type != KEY_TYPE_stripe) {
 447                 ret = -ENOENT;
 448                 goto err;
 449         }
 450         bkey_reassemble(&stripe->key.k_i, k);
 451 err:
 452         bch2_trans_iter_exit(&trans, &iter);
 453         bch2_trans_exit(&trans);
 454         return ret;
 455 }
 456
 457 /* recovery read path: */
 458 int bch2_ec_read_extent(struct bch_fs *c, struct bch_read_bio *rbio)
 459 {
 460         struct ec_stripe_buf *buf;
 461         struct closure cl;
 462         struct bch_stripe *v;
 463         unsigned i, offset;
 464         int ret = 0;
 465
 466         closure_init_stack(&cl);
 467
 468         BUG_ON(!rbio->pick.has_ec);
 469
 470         buf = kzalloc(sizeof(*buf), GFP_NOIO);
 471         if (!buf)
 472                 return -ENOMEM;
 473
 474         ret = get_stripe_key(c, rbio->pick.ec.idx, buf);
 475         if (ret) {
 476                 bch_err_ratelimited(c,
 477                         "error doing reconstruct read: error %i looking up stripe", ret);
 478                 kfree(buf);
 479                 return -EIO;
 480         }
 481
 482         v = &buf->key.v;
 483
 484         if (!bch2_ptr_matches_stripe(v, rbio->pick)) {
 485                 bch_err_ratelimited(c,
 486                         "error doing reconstruct read: pointer doesn't match stripe");
 487                 ret = -EIO;
 488                 goto err;
 489         }
 490
 491         offset = rbio->bio.bi_iter.bi_sector - v->ptrs[rbio->pick.ec.block].offset;
 492         if (offset + bio_sectors(&rbio->bio) > le16_to_cpu(v->sectors)) {
 493                 bch_err_ratelimited(c,
 494                         "error doing reconstruct read: read is bigger than stripe");
 495                 ret = -EIO;
 496                 goto err;
 497         }
 498
 499         ret = ec_stripe_buf_init(buf, offset, bio_sectors(&rbio->bio));
 500         if (ret)
 501                 goto err;
 502
 503         for (i = 0; i < v->nr_blocks; i++)
 504                 ec_block_io(c, buf, REQ_OP_READ, i, &cl);
 505
 506         closure_sync(&cl);
 507
 508         if (ec_nr_failed(buf) > v->nr_redundant) {
 509                 bch_err_ratelimited(c,
 510                         "error doing reconstruct read: unable to read enough blocks");
 511                 ret = -EIO;
 512                 goto err;
 513         }
 514
 515         ec_validate_checksums(c, buf);
 516
 517         ret = ec_do_recov(c, buf);
 518         if (ret)
 519                 goto err;
 520
 521         memcpy_to_bio(&rbio->bio, rbio->bio.bi_iter,
 522                       buf->data[rbio->pick.ec.block] + ((offset - buf->offset) << 9));
 523 err:
 524         ec_stripe_buf_exit(buf);
 525         kfree(buf);
 526         return ret;
 527 }
 528
 529 /* stripe bucket accounting: */
 530
 531 static int __ec_stripe_mem_alloc(struct bch_fs *c, size_t idx, gfp_t gfp)
 532 {
 533         ec_stripes_heap n, *h = &c->ec_stripes_heap;
 534
 535         if (idx >= h->size) {
 536                 if (!init_heap(&n, max(1024UL, roundup_pow_of_two(idx + 1)), gfp))
 537                         return -ENOMEM;
 538
 539                 spin_lock(&c->ec_stripes_heap_lock);
 540                 if (n.size > h->size) {
 541                         memcpy(n.data, h->data, h->used * sizeof(h->data[0]));
 542                         n.used = h->used;
 543                         swap(*h, n);
 544                 }
 545                 spin_unlock(&c->ec_stripes_heap_lock);
 546
 547                 free_heap(&n);
 548         }
 549
 550         if (!genradix_ptr_alloc(&c->stripes, idx, gfp))
 551                 return -ENOMEM;
 552
 553         if (c->gc_pos.phase != GC_PHASE_NOT_RUNNING &&
 554             !genradix_ptr_alloc(&c->gc_stripes, idx, gfp))
 555                 return -ENOMEM;
 556
 557         return 0;
 558 }
 559
 560 static int ec_stripe_mem_alloc(struct btree_trans *trans,
 561                                struct btree_iter *iter)
 562 {
 563         size_t idx = iter->pos.offset;
 564         int ret = 0;
 565
 566         if (!__ec_stripe_mem_alloc(trans->c, idx, GFP_NOWAIT|__GFP_NOWARN))
 567                 return ret;
 568
 569         bch2_trans_unlock(trans);
 570         ret = -EINTR;
 571
 572         if (!__ec_stripe_mem_alloc(trans->c, idx, GFP_KERNEL))
 573                 return ret;
 574
 575         return -ENOMEM;
 576 }
 577
 578 static ssize_t stripe_idx_to_delete(struct bch_fs *c)
 579 {
 580         ec_stripes_heap *h = &c->ec_stripes_heap;
 581
 582         return h->used && h->data[0].blocks_nonempty == 0
 583                 ? h->data[0].idx : -1;
 584 }
 585
 586 static inline int ec_stripes_heap_cmp(ec_stripes_heap *h,
 587                                       struct ec_stripe_heap_entry l,
 588                                       struct ec_stripe_heap_entry r)
 589 {
 590         return ((l.blocks_nonempty > r.blocks_nonempty) -
 591                 (l.blocks_nonempty < r.blocks_nonempty));
 592 }
 593
 594 static inline void ec_stripes_heap_set_backpointer(ec_stripes_heap *h,
 595                                                    size_t i)
 596 {
 597         struct bch_fs *c = container_of(h, struct bch_fs, ec_stripes_heap);
 598
 599         genradix_ptr(&c->stripes, h->data[i].idx)->heap_idx = i;
 600 }
 601
 602 static void heap_verify_backpointer(struct bch_fs *c, size_t idx)
 603 {
 604         ec_stripes_heap *h = &c->ec_stripes_heap;
 605         struct stripe *m = genradix_ptr(&c->stripes, idx);
 606
 607         BUG_ON(!m->alive);
 608         BUG_ON(m->heap_idx >= h->used);
 609         BUG_ON(h->data[m->heap_idx].idx != idx);
 610 }
 611
 612 void bch2_stripes_heap_del(struct bch_fs *c,
 613                            struct stripe *m, size_t idx)
 614 {
 615         if (!m->on_heap)
 616                 return;
 617
 618         m->on_heap = false;
 619
 620         heap_verify_backpointer(c, idx);
 621
 622         heap_del(&c->ec_stripes_heap, m->heap_idx,
 623                  ec_stripes_heap_cmp,
 624                  ec_stripes_heap_set_backpointer);
 625 }
 626
 627 void bch2_stripes_heap_insert(struct bch_fs *c,
 628                               struct stripe *m, size_t idx)
 629 {
 630         if (m->on_heap)
 631                 return;
 632
 633         BUG_ON(heap_full(&c->ec_stripes_heap));
 634
 635         m->on_heap = true;
 636
 637         heap_add(&c->ec_stripes_heap, ((struct ec_stripe_heap_entry) {
 638                         .idx = idx,
 639                         .blocks_nonempty = m->blocks_nonempty,
 640                 }),
 641                  ec_stripes_heap_cmp,
 642                  ec_stripes_heap_set_backpointer);
 643
 644         heap_verify_backpointer(c, idx);
 645 }
 646
 647 void bch2_stripes_heap_update(struct bch_fs *c,
 648                               struct stripe *m, size_t idx)
 649 {
 650         ec_stripes_heap *h = &c->ec_stripes_heap;
 651         size_t i;
 652
 653         if (!m->on_heap)
 654                 return;
 655
 656         heap_verify_backpointer(c, idx);
 657
 658         h->data[m->heap_idx].blocks_nonempty = m->blocks_nonempty;
 659
 660         i = m->heap_idx;
 661         heap_sift_up(h,   i, ec_stripes_heap_cmp,
 662                      ec_stripes_heap_set_backpointer);
 663         heap_sift_down(h, i, ec_stripes_heap_cmp,
 664                        ec_stripes_heap_set_backpointer);
 665
 666         heap_verify_backpointer(c, idx);
 667
 668         if (stripe_idx_to_delete(c) >= 0 &&
 669             !percpu_ref_is_dying(&c->writes))
 670                 schedule_work(&c->ec_stripe_delete_work);
 671 }
 672
 673 /* stripe deletion */
 674
 675 static int ec_stripe_delete(struct bch_fs *c, size_t idx)
 676 {
 677         return bch2_btree_delete_range(c, BTREE_ID_stripes,
 678                                        POS(0, idx),
 679                                        POS(0, idx + 1),
 680                                        NULL);
 681 }
 682
 683 static void ec_stripe_delete_work(struct work_struct *work)
 684 {
 685         struct bch_fs *c =
 686                 container_of(work, struct bch_fs, ec_stripe_delete_work);
 687         ssize_t idx;
 688
 689         while (1) {
 690                 spin_lock(&c->ec_stripes_heap_lock);
 691                 idx = stripe_idx_to_delete(c);
 692                 if (idx < 0) {
 693                         spin_unlock(&c->ec_stripes_heap_lock);
 694                         break;
 695                 }
 696
 697                 bch2_stripes_heap_del(c, genradix_ptr(&c->stripes, idx), idx);
 698                 spin_unlock(&c->ec_stripes_heap_lock);
 699
 700                 if (ec_stripe_delete(c, idx))
 701                         break;
 702         }
 703 }
 704
 705 /* stripe creation: */
 706
 707 static int ec_stripe_bkey_insert(struct btree_trans *trans,
 708                                  struct bkey_i_stripe *stripe,
 709                                  struct disk_reservation *res)
 710 {
 711         struct bch_fs *c = trans->c;
 712         struct btree_iter iter;
 713         struct bkey_s_c k;
 714         struct bpos min_pos = POS(0, 1);
 715         struct bpos start_pos = bpos_max(min_pos, POS(0, c->ec_stripe_hint));
 716         int ret;
 717
 718         for_each_btree_key(trans, iter, BTREE_ID_stripes, start_pos,
 719                            BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
 720                 if (bkey_cmp(k.k->p, POS(0, U32_MAX)) > 0) {
 721                         if (start_pos.offset) {
 722                                 start_pos = min_pos;
 723                                 bch2_btree_iter_set_pos(&iter, start_pos);
 724                                 continue;
 725                         }
 726
 727                         ret = -ENOSPC;
 728                         break;
 729                 }
 730
 731                 if (bkey_deleted(k.k))
 732                         goto found_slot;
 733         }
 734
 735         goto err;
 736 found_slot:
 737         start_pos = iter.pos;
 738
 739         ret = ec_stripe_mem_alloc(trans, &iter);
 740         if (ret)
 741                 goto err;
 742
 743         stripe->k.p = iter.pos;
 744
 745         ret = bch2_trans_update(trans, &iter, &stripe->k_i, 0);
 746
 747         c->ec_stripe_hint = start_pos.offset;
 748 err:
 749         bch2_trans_iter_exit(trans, &iter);
 750
 751         return ret;
 752 }
 753
 754 static int ec_stripe_bkey_update(struct btree_trans *trans,
 755                                  struct bkey_i_stripe *new,
 756                                  struct disk_reservation *res)
 757 {
 758         struct btree_iter iter;
 759         struct bkey_s_c k;
 760         const struct bch_stripe *existing;
 761         unsigned i;
 762         int ret;
 763
 764         bch2_trans_iter_init(trans, &iter, BTREE_ID_stripes,
 765                              new->k.p, BTREE_ITER_INTENT);
 766         k = bch2_btree_iter_peek_slot(&iter);
 767         ret = bkey_err(k);
 768         if (ret)
 769                 goto err;
 770
 771         if (!k.k || k.k->type != KEY_TYPE_stripe) {
 772                 bch_err(trans->c, "error updating stripe: not found");
 773                 ret = -ENOENT;
 774                 goto err;
 775         }
 776
 777         existing = bkey_s_c_to_stripe(k).v;
 778
 779         if (existing->nr_blocks != new->v.nr_blocks) {
 780                 bch_err(trans->c, "error updating stripe: nr_blocks does not match");
 781                 ret = -EINVAL;
 782                 goto err;
 783         }
 784
 785         for (i = 0; i < new->v.nr_blocks; i++)
 786                 stripe_blockcount_set(&new->v, i,
 787                         stripe_blockcount_get(existing, i));
 788
 789         ret = bch2_trans_update(trans, &iter, &new->k_i, 0);
 790 err:
 791         bch2_trans_iter_exit(trans, &iter);
 792         return ret;
 793 }
 794
 795 static void extent_stripe_ptr_add(struct bkey_s_extent e,
 796                                   struct ec_stripe_buf *s,
 797                                   struct bch_extent_ptr *ptr,
 798                                   unsigned block)
 799 {
 800         struct bch_extent_stripe_ptr *dst = (void *) ptr;
 801         union bch_extent_entry *end = extent_entry_last(e);
 802
 803         memmove_u64s_up(dst + 1, dst, (u64 *) end - (u64 *) dst);
 804         e.k->u64s += sizeof(*dst) / sizeof(u64);
 805
 806         *dst = (struct bch_extent_stripe_ptr) {
 807                 .type = 1 << BCH_EXTENT_ENTRY_stripe_ptr,
 808                 .block          = block,
 809                 .redundancy     = s->key.v.nr_redundant,
 810                 .idx            = s->key.k.p.offset,
 811         };
 812 }
 813
 814 static int ec_stripe_update_ptrs(struct bch_fs *c,
 815                                  struct ec_stripe_buf *s,
 816                                  struct bkey *pos)
 817 {
 818         struct btree_trans trans;
 819         struct btree_iter iter;
 820         struct bkey_s_c k;
 821         struct bkey_s_extent e;
 822         struct bkey_buf sk;
 823         struct bpos next_pos;
 824         int ret = 0, dev, block;
 825
 826         bch2_bkey_buf_init(&sk);
 827         bch2_trans_init(&trans, c, BTREE_ITER_MAX, 0);
 828
 829         /* XXX this doesn't support the reflink btree */
 830
 831         bch2_trans_iter_init(&trans, &iter, BTREE_ID_extents,
 832                              bkey_start_pos(pos),
 833                              BTREE_ITER_INTENT);
 834 retry:
 835         while (bch2_trans_begin(&trans),
 836                (k = bch2_btree_iter_peek(&iter)).k &&
 837                !(ret = bkey_err(k)) &&
 838                bkey_cmp(bkey_start_pos(k.k), pos->p) < 0) {
 839                 const struct bch_extent_ptr *ptr_c;
 840                 struct bch_extent_ptr *ptr, *ec_ptr = NULL;
 841
 842                 if (extent_has_stripe_ptr(k, s->key.k.p.offset)) {
 843                         bch2_btree_iter_advance(&iter);
 844                         continue;
 845                 }
 846
 847                 ptr_c = bkey_matches_stripe(&s->key.v, k, &block);
 848                 /*
 849                  * It doesn't generally make sense to erasure code cached ptrs:
 850                  * XXX: should we be incrementing a counter?
 851                  */
 852                 if (!ptr_c || ptr_c->cached) {
 853                         bch2_btree_iter_advance(&iter);
 854                         continue;
 855                 }
 856
 857                 dev = s->key.v.ptrs[block].dev;
 858
 859                 bch2_bkey_buf_reassemble(&sk, c, k);
 860                 e = bkey_i_to_s_extent(sk.k);
 861
 862                 bch2_bkey_drop_ptrs(e.s, ptr, ptr->dev != dev);
 863                 ec_ptr = (void *) bch2_bkey_has_device(e.s_c, dev);
 864                 BUG_ON(!ec_ptr);
 865
 866                 extent_stripe_ptr_add(e, s, ec_ptr, block);
 867
 868                 bch2_btree_iter_set_pos(&iter, bkey_start_pos(&sk.k->k));
 869                 next_pos = sk.k->k.p;
 870
 871                 ret   = bch2_btree_iter_traverse(&iter) ?:
 872                         bch2_trans_update(&trans, &iter, sk.k, 0) ?:
 873                         bch2_trans_commit(&trans, NULL, NULL,
 874                                         BTREE_INSERT_NOFAIL);
 875                 if (!ret)
 876                         bch2_btree_iter_set_pos(&iter, next_pos);
 877                 if (ret)
 878                         break;
 879         }
 880         if (ret == -EINTR)
 881                 goto retry;
 882         bch2_trans_iter_exit(&trans, &iter);
 883
 884         bch2_trans_exit(&trans);
 885         bch2_bkey_buf_exit(&sk, c);
 886
 887         return ret;
 888 }
 889
 890 /*
 891  * data buckets of new stripe all written: create the stripe
 892  */
 893 static void ec_stripe_create(struct ec_stripe_new *s)
 894 {
 895         struct bch_fs *c = s->c;
 896         struct open_bucket *ob;
 897         struct bkey_i *k;
 898         struct stripe *m;
 899         struct bch_stripe *v = &s->new_stripe.key.v;
 900         unsigned i, nr_data = v->nr_blocks - v->nr_redundant;
 901         int ret;
 902
 903         BUG_ON(s->h->s == s);
 904
 905         closure_sync(&s->iodone);
 906
 907         if (s->err) {
 908                 if (s->err != -EROFS)
 909                         bch_err(c, "error creating stripe: error writing data buckets");
 910                 goto err;
 911         }
 912
 913         if (s->have_existing_stripe) {
 914                 ec_validate_checksums(c, &s->existing_stripe);
 915
 916                 if (ec_do_recov(c, &s->existing_stripe)) {
 917                         bch_err(c, "error creating stripe: error reading existing stripe");
 918                         goto err;
 919                 }
 920
 921                 for (i = 0; i < nr_data; i++)
 922                         if (stripe_blockcount_get(&s->existing_stripe.key.v, i))
 923                                 swap(s->new_stripe.data[i],
 924                                      s->existing_stripe.data[i]);
 925
 926                 ec_stripe_buf_exit(&s->existing_stripe);
 927         }
 928
 929         BUG_ON(!s->allocated);
 930
 931         if (!percpu_ref_tryget(&c->writes))
 932                 goto err;
 933
 934         ec_generate_ec(&s->new_stripe);
 935
 936         ec_generate_checksums(&s->new_stripe);
 937
 938         /* write p/q: */
 939         for (i = nr_data; i < v->nr_blocks; i++)
 940                 ec_block_io(c, &s->new_stripe, REQ_OP_WRITE, i, &s->iodone);
 941         closure_sync(&s->iodone);
 942
 943         if (ec_nr_failed(&s->new_stripe)) {
 944                 bch_err(c, "error creating stripe: error writing redundancy buckets");
 945                 goto err_put_writes;
 946         }
 947
 948         ret = bch2_trans_do(c, &s->res, NULL, BTREE_INSERT_NOFAIL,
 949                             s->have_existing_stripe
 950                             ? ec_stripe_bkey_update(&trans, &s->new_stripe.key, &s->res)
 951                             : ec_stripe_bkey_insert(&trans, &s->new_stripe.key, &s->res));
 952         if (ret) {
 953                 bch_err(c, "error creating stripe: error creating stripe key");
 954                 goto err_put_writes;
 955         }
 956
 957         for_each_keylist_key(&s->keys, k) {
 958                 ret = ec_stripe_update_ptrs(c, &s->new_stripe, &k->k);
 959                 if (ret) {
 960                         bch_err(c, "error creating stripe: error %i updating pointers", ret);
 961                         break;
 962                 }
 963         }
 964
 965         spin_lock(&c->ec_stripes_heap_lock);
 966         m = genradix_ptr(&c->stripes, s->new_stripe.key.k.p.offset);
 967
 968         BUG_ON(m->on_heap);
 969         bch2_stripes_heap_insert(c, m, s->new_stripe.key.k.p.offset);
 970         spin_unlock(&c->ec_stripes_heap_lock);
 971 err_put_writes:
 972         percpu_ref_put(&c->writes);
 973 err:
 974         bch2_disk_reservation_put(c, &s->res);
 975
 976         for (i = 0; i < v->nr_blocks; i++)
 977                 if (s->blocks[i]) {
 978                         ob = c->open_buckets + s->blocks[i];
 979
 980                         if (i < nr_data) {
 981                                 ob->ec = NULL;
 982                                 __bch2_open_bucket_put(c, ob);
 983                         } else {
 984                                 bch2_open_bucket_put(c, ob);
 985                         }
 986                 }
 987
 988         bch2_keylist_free(&s->keys, s->inline_keys);
 989
 990         ec_stripe_buf_exit(&s->existing_stripe);
 991         ec_stripe_buf_exit(&s->new_stripe);
 992         closure_debug_destroy(&s->iodone);
 993         kfree(s);
 994 }
 995
 996 static void ec_stripe_create_work(struct work_struct *work)
 997 {
 998         struct bch_fs *c = container_of(work,
 999                 struct bch_fs, ec_stripe_create_work);
1000         struct ec_stripe_new *s, *n;
1001 restart:
1002         mutex_lock(&c->ec_stripe_new_lock);
1003         list_for_each_entry_safe(s, n, &c->ec_stripe_new_list, list)
1004                 if (!atomic_read(&s->pin)) {
1005                         list_del(&s->list);
1006                         mutex_unlock(&c->ec_stripe_new_lock);
1007                         ec_stripe_create(s);
1008                         goto restart;
1009                 }
1010         mutex_unlock(&c->ec_stripe_new_lock);
1011 }
1012
1013 static void ec_stripe_new_put(struct bch_fs *c, struct ec_stripe_new *s)
1014 {
1015         BUG_ON(atomic_read(&s->pin) <= 0);
1016
1017         if (atomic_dec_and_test(&s->pin)) {
1018                 BUG_ON(!s->pending);
1019                 queue_work(system_long_wq, &c->ec_stripe_create_work);
1020         }
1021 }
1022
1023 static void ec_stripe_set_pending(struct bch_fs *c, struct ec_stripe_head *h)
1024 {
1025         struct ec_stripe_new *s = h->s;
1026
1027         BUG_ON(!s->allocated && !s->err);
1028
1029         h->s            = NULL;
1030         s->pending      = true;
1031
1032         mutex_lock(&c->ec_stripe_new_lock);
1033         list_add(&s->list, &c->ec_stripe_new_list);
1034         mutex_unlock(&c->ec_stripe_new_lock);
1035
1036         ec_stripe_new_put(c, s);
1037 }
1038
1039 /* have a full bucket - hand it off to be erasure coded: */
1040 void bch2_ec_bucket_written(struct bch_fs *c, struct open_bucket *ob)
1041 {
1042         struct ec_stripe_new *s = ob->ec;
1043
1044         if (ob->sectors_free)
1045                 s->err = -1;
1046
1047         ec_stripe_new_put(c, s);
1048 }
1049
1050 void bch2_ec_bucket_cancel(struct bch_fs *c, struct open_bucket *ob)
1051 {
1052         struct ec_stripe_new *s = ob->ec;
1053
1054         s->err = -EIO;
1055 }
1056
1057 void *bch2_writepoint_ec_buf(struct bch_fs *c, struct write_point *wp)
1058 {
1059         struct open_bucket *ob = ec_open_bucket(c, &wp->ptrs);
1060         struct bch_dev *ca;
1061         unsigned offset;
1062
1063         if (!ob)
1064                 return NULL;
1065
1066         ca      = bch_dev_bkey_exists(c, ob->ptr.dev);
1067         offset  = ca->mi.bucket_size - ob->sectors_free;
1068
1069         return ob->ec->new_stripe.data[ob->ec_idx] + (offset << 9);
1070 }
1071
1072 void bch2_ob_add_backpointer(struct bch_fs *c, struct open_bucket *ob,
1073                              struct bkey *k)
1074 {
1075         struct ec_stripe_new *ec = ob->ec;
1076
1077         if (!ec)
1078                 return;
1079
1080         mutex_lock(&ec->lock);
1081
1082         if (bch2_keylist_realloc(&ec->keys, ec->inline_keys,
1083                                  ARRAY_SIZE(ec->inline_keys),
1084                                  BKEY_U64s)) {
1085                 BUG();
1086         }
1087
1088         bkey_init(&ec->keys.top->k);
1089         ec->keys.top->k.p       = k->p;
1090         ec->keys.top->k.size    = k->size;
1091         bch2_keylist_push(&ec->keys);
1092
1093         mutex_unlock(&ec->lock);
1094 }
1095
1096 static int unsigned_cmp(const void *_l, const void *_r)
1097 {
1098         unsigned l = *((const unsigned *) _l);
1099         unsigned r = *((const unsigned *) _r);
1100
1101         return cmp_int(l, r);
1102 }
1103
1104 /* pick most common bucket size: */
1105 static unsigned pick_blocksize(struct bch_fs *c,
1106                                struct bch_devs_mask *devs)
1107 {
1108         struct bch_dev *ca;
1109         unsigned i, nr = 0, sizes[BCH_SB_MEMBERS_MAX];
1110         struct {
1111                 unsigned nr, size;
1112         } cur = { 0, 0 }, best = { 0, 0 };
1113
1114         for_each_member_device_rcu(ca, c, i, devs)
1115                 sizes[nr++] = ca->mi.bucket_size;
1116
1117         sort(sizes, nr, sizeof(unsigned), unsigned_cmp, NULL);
1118
1119         for (i = 0; i < nr; i++) {
1120                 if (sizes[i] != cur.size) {
1121                         if (cur.nr > best.nr)
1122                                 best = cur;
1123
1124                         cur.nr = 0;
1125                         cur.size = sizes[i];
1126                 }
1127
1128                 cur.nr++;
1129         }
1130
1131         if (cur.nr > best.nr)
1132                 best = cur;
1133
1134         return best.size;
1135 }
1136
1137 static bool may_create_new_stripe(struct bch_fs *c)
1138 {
1139         return false;
1140 }
1141
1142 static void ec_stripe_key_init(struct bch_fs *c,
1143                                struct bkey_i_stripe *s,
1144                                unsigned nr_data,
1145                                unsigned nr_parity,
1146                                unsigned stripe_size)
1147 {
1148         unsigned u64s;
1149
1150         bkey_stripe_init(&s->k_i);
1151         s->v.sectors                    = cpu_to_le16(stripe_size);
1152         s->v.algorithm                  = 0;
1153         s->v.nr_blocks                  = nr_data + nr_parity;
1154         s->v.nr_redundant               = nr_parity;
1155         s->v.csum_granularity_bits      = ilog2(c->sb.encoded_extent_max);
1156         s->v.csum_type                  = BCH_CSUM_crc32c;
1157         s->v.pad                        = 0;
1158
1159         while ((u64s = stripe_val_u64s(&s->v)) > BKEY_VAL_U64s_MAX) {
1160                 BUG_ON(1 << s->v.csum_granularity_bits >=
1161                        le16_to_cpu(s->v.sectors) ||
1162                        s->v.csum_granularity_bits == U8_MAX);
1163                 s->v.csum_granularity_bits++;
1164         }
1165
1166         set_bkey_val_u64s(&s->k, u64s);
1167 }
1168
1169 static int ec_new_stripe_alloc(struct bch_fs *c, struct ec_stripe_head *h)
1170 {
1171         struct ec_stripe_new *s;
1172
1173         lockdep_assert_held(&h->lock);
1174
1175         s = kzalloc(sizeof(*s), GFP_KERNEL);
1176         if (!s)
1177                 return -ENOMEM;
1178
1179         mutex_init(&s->lock);
1180         closure_init(&s->iodone, NULL);
1181         atomic_set(&s->pin, 1);
1182         s->c            = c;
1183         s->h            = h;
1184         s->nr_data      = min_t(unsigned, h->nr_active_devs,
1185                                 BCH_BKEY_PTRS_MAX) - h->redundancy;
1186         s->nr_parity    = h->redundancy;
1187
1188         bch2_keylist_init(&s->keys, s->inline_keys);
1189
1190         ec_stripe_key_init(c, &s->new_stripe.key, s->nr_data,
1191                            s->nr_parity, h->blocksize);
1192
1193         h->s = s;
1194         return 0;
1195 }
1196
1197 static struct ec_stripe_head *
1198 ec_new_stripe_head_alloc(struct bch_fs *c, unsigned target,
1199                          unsigned algo, unsigned redundancy,
1200                          bool copygc)
1201 {
1202         struct ec_stripe_head *h;
1203         struct bch_dev *ca;
1204         unsigned i;
1205
1206         h = kzalloc(sizeof(*h), GFP_KERNEL);
1207         if (!h)
1208                 return NULL;
1209
1210         mutex_init(&h->lock);
1211         mutex_lock(&h->lock);
1212
1213         h->target       = target;
1214         h->algo         = algo;
1215         h->redundancy   = redundancy;
1216         h->copygc       = copygc;
1217
1218         rcu_read_lock();
1219         h->devs = target_rw_devs(c, BCH_DATA_user, target);
1220
1221         for_each_member_device_rcu(ca, c, i, &h->devs)
1222                 if (!ca->mi.durability)
1223                         __clear_bit(i, h->devs.d);
1224
1225         h->blocksize = pick_blocksize(c, &h->devs);
1226
1227         for_each_member_device_rcu(ca, c, i, &h->devs)
1228                 if (ca->mi.bucket_size == h->blocksize)
1229                         h->nr_active_devs++;
1230
1231         rcu_read_unlock();
1232         list_add(&h->list, &c->ec_stripe_head_list);
1233         return h;
1234 }
1235
1236 void bch2_ec_stripe_head_put(struct bch_fs *c, struct ec_stripe_head *h)
1237 {
1238         if (h->s &&
1239             h->s->allocated &&
1240             bitmap_weight(h->s->blocks_allocated,
1241                           h->s->nr_data) == h->s->nr_data)
1242                 ec_stripe_set_pending(c, h);
1243
1244         mutex_unlock(&h->lock);
1245 }
1246
1247 struct ec_stripe_head *__bch2_ec_stripe_head_get(struct bch_fs *c,
1248                                                  unsigned target,
1249                                                  unsigned algo,
1250                                                  unsigned redundancy,
1251                                                  bool copygc)
1252 {
1253         struct ec_stripe_head *h;
1254
1255         if (!redundancy)
1256                 return NULL;
1257
1258         mutex_lock(&c->ec_stripe_head_lock);
1259         list_for_each_entry(h, &c->ec_stripe_head_list, list)
1260                 if (h->target           == target &&
1261                     h->algo             == algo &&
1262                     h->redundancy       == redundancy &&
1263                     h->copygc           == copygc) {
1264                         mutex_lock(&h->lock);
1265                         goto found;
1266                 }
1267
1268         h = ec_new_stripe_head_alloc(c, target, algo, redundancy, copygc);
1269 found:
1270         mutex_unlock(&c->ec_stripe_head_lock);
1271         return h;
1272 }
1273
1274 static int new_stripe_alloc_buckets(struct bch_fs *c, struct ec_stripe_head *h,
1275                                     struct closure *cl)
1276 {
1277         struct bch_devs_mask devs = h->devs;
1278         struct open_bucket *ob;
1279         struct open_buckets buckets;
1280         unsigned i, j, nr_have_parity = 0, nr_have_data = 0;
1281         bool have_cache = true;
1282         int ret = 0;
1283
1284         for (i = 0; i < h->s->new_stripe.key.v.nr_blocks; i++) {
1285                 if (test_bit(i, h->s->blocks_gotten)) {
1286                         __clear_bit(h->s->new_stripe.key.v.ptrs[i].dev, devs.d);
1287                         if (i < h->s->nr_data)
1288                                 nr_have_data++;
1289                         else
1290                                 nr_have_parity++;
1291                 }
1292         }
1293
1294         BUG_ON(nr_have_data     > h->s->nr_data);
1295         BUG_ON(nr_have_parity   > h->s->nr_parity);
1296
1297         percpu_down_read(&c->mark_lock);
1298         rcu_read_lock();
1299
1300         buckets.nr = 0;
1301         if (nr_have_parity < h->s->nr_parity) {
1302                 ret = bch2_bucket_alloc_set(c, &buckets,
1303                                             &h->parity_stripe,
1304                                             &devs,
1305                                             h->s->nr_parity,
1306                                             &nr_have_parity,
1307                                             &have_cache,
1308                                             h->copygc
1309                                             ? RESERVE_MOVINGGC
1310                                             : RESERVE_NONE,
1311                                             0,
1312                                             cl);
1313
1314                 open_bucket_for_each(c, &buckets, ob, i) {
1315                         j = find_next_zero_bit(h->s->blocks_gotten,
1316                                                h->s->nr_data + h->s->nr_parity,
1317                                                h->s->nr_data);
1318                         BUG_ON(j >= h->s->nr_data + h->s->nr_parity);
1319
1320                         h->s->blocks[j] = buckets.v[i];
1321                         h->s->new_stripe.key.v.ptrs[j] = ob->ptr;
1322                         __set_bit(j, h->s->blocks_gotten);
1323                 }
1324
1325                 if (ret)
1326                         goto err;
1327         }
1328
1329         buckets.nr = 0;
1330         if (nr_have_data < h->s->nr_data) {
1331                 ret = bch2_bucket_alloc_set(c, &buckets,
1332                                             &h->block_stripe,
1333                                             &devs,
1334                                             h->s->nr_data,
1335                                             &nr_have_data,
1336                                             &have_cache,
1337                                             h->copygc
1338                                             ? RESERVE_MOVINGGC
1339                                             : RESERVE_NONE,
1340                                             0,
1341                                             cl);
1342
1343                 open_bucket_for_each(c, &buckets, ob, i) {
1344                         j = find_next_zero_bit(h->s->blocks_gotten,
1345                                                h->s->nr_data, 0);
1346                         BUG_ON(j >= h->s->nr_data);
1347
1348                         h->s->blocks[j] = buckets.v[i];
1349                         h->s->new_stripe.key.v.ptrs[j] = ob->ptr;
1350                         __set_bit(j, h->s->blocks_gotten);
1351                 }
1352
1353                 if (ret)
1354                         goto err;
1355         }
1356 err:
1357         rcu_read_unlock();
1358         percpu_up_read(&c->mark_lock);
1359         return ret;
1360 }
1361
1362 /* XXX: doesn't obey target: */
1363 static s64 get_existing_stripe(struct bch_fs *c,
1364                                struct ec_stripe_head *head)
1365 {
1366         ec_stripes_heap *h = &c->ec_stripes_heap;
1367         struct stripe *m;
1368         size_t heap_idx;
1369         u64 stripe_idx;
1370         s64 ret = -1;
1371
1372         if (may_create_new_stripe(c))
1373                 return -1;
1374
1375         spin_lock(&c->ec_stripes_heap_lock);
1376         for (heap_idx = 0; heap_idx < h->used; heap_idx++) {
1377                 /* No blocks worth reusing, stripe will just be deleted: */
1378                 if (!h->data[heap_idx].blocks_nonempty)
1379                         continue;
1380
1381                 stripe_idx = h->data[heap_idx].idx;
1382                 m = genradix_ptr(&c->stripes, stripe_idx);
1383
1384                 if (m->algorithm        == head->algo &&
1385                     m->nr_redundant     == head->redundancy &&
1386                     m->sectors          == head->blocksize &&
1387                     m->blocks_nonempty  < m->nr_blocks - m->nr_redundant) {
1388                         bch2_stripes_heap_del(c, m, stripe_idx);
1389                         ret = stripe_idx;
1390                         break;
1391                 }
1392         }
1393         spin_unlock(&c->ec_stripes_heap_lock);
1394         return ret;
1395 }
1396
1397 static int __bch2_ec_stripe_head_reuse(struct bch_fs *c,
1398                                                    struct ec_stripe_head *h)
1399 {
1400         unsigned i;
1401         s64 idx;
1402         int ret;
1403
1404         idx = get_existing_stripe(c, h);
1405         if (idx < 0) {
1406                 bch_err(c, "failed to find an existing stripe");
1407                 return -ENOSPC;
1408         }
1409
1410         h->s->have_existing_stripe = true;
1411         ret = get_stripe_key(c, idx, &h->s->existing_stripe);
1412         if (ret) {
1413                 bch2_fs_fatal_error(c, "error reading stripe key: %i", ret);
1414                 return ret;
1415         }
1416
1417         if (ec_stripe_buf_init(&h->s->existing_stripe, 0, h->blocksize)) {
1418                 /*
1419                  * this is a problem: we have deleted from the
1420                  * stripes heap already
1421                  */
1422                 BUG();
1423         }
1424
1425         BUG_ON(h->s->existing_stripe.size != h->blocksize);
1426         BUG_ON(h->s->existing_stripe.size != h->s->existing_stripe.key.v.sectors);
1427
1428         for (i = 0; i < h->s->existing_stripe.key.v.nr_blocks; i++) {
1429                 if (stripe_blockcount_get(&h->s->existing_stripe.key.v, i)) {
1430                         __set_bit(i, h->s->blocks_gotten);
1431                         __set_bit(i, h->s->blocks_allocated);
1432                 }
1433
1434                 ec_block_io(c, &h->s->existing_stripe, READ, i, &h->s->iodone);
1435         }
1436
1437         bkey_copy(&h->s->new_stripe.key.k_i,
1438                         &h->s->existing_stripe.key.k_i);
1439
1440         return 0;
1441 }
1442
1443 static int __bch2_ec_stripe_head_reserve(struct bch_fs *c,
1444                                                         struct ec_stripe_head *h)
1445 {
1446         int ret;
1447
1448         ret = bch2_disk_reservation_get(c, &h->s->res,
1449                         h->blocksize,
1450                         h->s->nr_parity, 0);
1451
1452         if (ret) {
1453                 /*
1454                  * This means we need to wait for copygc to
1455                  * empty out buckets from existing stripes:
1456                  */
1457                 bch_err(c, "failed to reserve stripe");
1458         }
1459
1460         return ret;
1461 }
1462
1463 struct ec_stripe_head *bch2_ec_stripe_head_get(struct bch_fs *c,
1464                                                unsigned target,
1465                                                unsigned algo,
1466                                                unsigned redundancy,
1467                                                bool copygc,
1468                                                struct closure *cl)
1469 {
1470         struct ec_stripe_head *h;
1471         int ret;
1472         bool needs_stripe_new;
1473
1474         h = __bch2_ec_stripe_head_get(c, target, algo, redundancy, copygc);
1475         if (!h) {
1476                 bch_err(c, "no stripe head");
1477                 return NULL;
1478         }
1479
1480         needs_stripe_new = !h->s;
1481         if (needs_stripe_new) {
1482                 if (ec_new_stripe_alloc(c, h)) {
1483                         ret = -ENOMEM;
1484                         bch_err(c, "failed to allocate new stripe");
1485                         goto err;
1486                 }
1487
1488                 if (ec_stripe_buf_init(&h->s->new_stripe, 0, h->blocksize))
1489                         BUG();
1490         }
1491
1492         /*
1493          * Try reserve a new stripe before reusing an
1494          * existing stripe. This will prevent unnecessary
1495          * read amplification during write oriented workloads.
1496          */
1497         ret = 0;
1498         if (!h->s->allocated && !h->s->res.sectors && !h->s->have_existing_stripe)
1499                 ret = __bch2_ec_stripe_head_reserve(c, h);
1500         if (ret && needs_stripe_new)
1501                 ret = __bch2_ec_stripe_head_reuse(c, h);
1502         if (ret)
1503                 goto err;
1504
1505         if (!h->s->allocated) {
1506                 ret = new_stripe_alloc_buckets(c, h, cl);
1507                 if (ret)
1508                         goto err;
1509
1510                 h->s->allocated = true;
1511         }
1512
1513         return h;
1514
1515 err:
1516         bch2_ec_stripe_head_put(c, h);
1517         return ERR_PTR(ret);
1518 }
1519
1520 void bch2_ec_stop_dev(struct bch_fs *c, struct bch_dev *ca)
1521 {
1522         struct ec_stripe_head *h;
1523         struct open_bucket *ob;
1524         unsigned i;
1525
1526         mutex_lock(&c->ec_stripe_head_lock);
1527         list_for_each_entry(h, &c->ec_stripe_head_list, list) {
1528
1529                 mutex_lock(&h->lock);
1530                 if (!h->s)
1531                         goto unlock;
1532
1533                 for (i = 0; i < h->s->new_stripe.key.v.nr_blocks; i++) {
1534                         if (!h->s->blocks[i])
1535                                 continue;
1536
1537                         ob = c->open_buckets + h->s->blocks[i];
1538                         if (ob->ptr.dev == ca->dev_idx)
1539                                 goto found;
1540                 }
1541                 goto unlock;
1542 found:
1543                 h->s->err = -EROFS;
1544                 ec_stripe_set_pending(c, h);
1545 unlock:
1546                 mutex_unlock(&h->lock);
1547         }
1548         mutex_unlock(&c->ec_stripe_head_lock);
1549 }
1550
1551 void bch2_stripes_heap_start(struct bch_fs *c)
1552 {
1553         struct genradix_iter iter;
1554         struct stripe *m;
1555
1556         genradix_for_each(&c->stripes, iter, m)
1557                 if (m->alive)
1558                         bch2_stripes_heap_insert(c, m, iter.pos);
1559 }
1560
1561 static int bch2_stripes_read_fn(struct btree_trans *trans, struct bkey_s_c k)
1562 {
1563         const struct bch_stripe *s;
1564         struct bch_fs *c = trans->c;
1565         struct stripe *m;
1566         unsigned i;
1567         int ret = 0;
1568
1569         if (k.k->type != KEY_TYPE_stripe)
1570                 return 0;
1571
1572         ret = __ec_stripe_mem_alloc(c, k.k->p.offset, GFP_KERNEL);
1573         if (ret)
1574                 return ret;
1575
1576         s = bkey_s_c_to_stripe(k).v;
1577
1578         m = genradix_ptr(&c->stripes, k.k->p.offset);
1579         m->alive        = true;
1580         m->sectors      = le16_to_cpu(s->sectors);
1581         m->algorithm    = s->algorithm;
1582         m->nr_blocks    = s->nr_blocks;
1583         m->nr_redundant = s->nr_redundant;
1584         m->blocks_nonempty = 0;
1585
1586         for (i = 0; i < s->nr_blocks; i++)
1587                 m->blocks_nonempty += !!stripe_blockcount_get(s, i);
1588
1589         spin_lock(&c->ec_stripes_heap_lock);
1590         bch2_stripes_heap_update(c, m, k.k->p.offset);
1591         spin_unlock(&c->ec_stripes_heap_lock);
1592
1593         return ret;
1594 }
1595
1596 int bch2_stripes_read(struct bch_fs *c)
1597 {
1598         struct btree_trans trans;
1599         int ret;
1600
1601         bch2_trans_init(&trans, c, 0, 0);
1602         ret = bch2_btree_and_journal_walk(&trans, BTREE_ID_stripes,
1603                                           bch2_stripes_read_fn);
1604         bch2_trans_exit(&trans);
1605         if (ret)
1606                 bch_err(c, "error reading stripes: %i", ret);
1607
1608         return ret;
1609 }
1610
1611 int bch2_ec_mem_alloc(struct bch_fs *c, bool gc)
1612 {
1613         struct btree_trans trans;
1614         struct btree_iter iter;
1615         struct bkey_s_c k;
1616         size_t i, idx = 0;
1617         int ret = 0;
1618
1619         bch2_trans_init(&trans, c, 0, 0);
1620         bch2_trans_iter_init(&trans, &iter, BTREE_ID_stripes, POS(0, U64_MAX), 0);
1621
1622         k = bch2_btree_iter_prev(&iter);
1623         ret = bkey_err(k);
1624         if (!ret && k.k)
1625                 idx = k.k->p.offset + 1;
1626
1627         bch2_trans_iter_exit(&trans, &iter);
1628         bch2_trans_exit(&trans);
1629         if (ret)
1630                 return ret;
1631
1632         if (!idx)
1633                 return 0;
1634
1635         if (!gc &&
1636             !init_heap(&c->ec_stripes_heap, roundup_pow_of_two(idx),
1637                        GFP_KERNEL))
1638                 return -ENOMEM;
1639 #if 0
1640         ret = genradix_prealloc(&c->stripes[gc], idx, GFP_KERNEL);
1641 #else
1642         for (i = 0; i < idx; i++)
1643                 if (!gc
1644                     ? !genradix_ptr_alloc(&c->stripes, i, GFP_KERNEL)
1645                     : !genradix_ptr_alloc(&c->gc_stripes, i, GFP_KERNEL))
1646                         return -ENOMEM;
1647 #endif
1648         return 0;
1649 }
1650
1651 void bch2_stripes_heap_to_text(struct printbuf *out, struct bch_fs *c)
1652 {
1653         ec_stripes_heap *h = &c->ec_stripes_heap;
1654         struct stripe *m;
1655         size_t i;
1656
1657         spin_lock(&c->ec_stripes_heap_lock);
1658         for (i = 0; i < min_t(size_t, h->used, 20); i++) {
1659                 m = genradix_ptr(&c->stripes, h->data[i].idx);
1660
1661                 pr_buf(out, "%zu %u/%u+%u\n", h->data[i].idx,
1662                        h->data[i].blocks_nonempty,
1663                        m->nr_blocks - m->nr_redundant,
1664                        m->nr_redundant);
1665         }
1666         spin_unlock(&c->ec_stripes_heap_lock);
1667 }
1668
1669 void bch2_new_stripes_to_text(struct printbuf *out, struct bch_fs *c)
1670 {
1671         struct ec_stripe_head *h;
1672         struct ec_stripe_new *s;
1673
1674         mutex_lock(&c->ec_stripe_head_lock);
1675         list_for_each_entry(h, &c->ec_stripe_head_list, list) {
1676                 pr_buf(out, "target %u algo %u redundancy %u:\n",
1677                        h->target, h->algo, h->redundancy);
1678
1679                 if (h->s)
1680                         pr_buf(out, "\tpending: blocks %u+%u allocated %u\n",
1681                                h->s->nr_data, h->s->nr_parity,
1682                                bitmap_weight(h->s->blocks_allocated,
1683                                              h->s->nr_data));
1684         }
1685         mutex_unlock(&c->ec_stripe_head_lock);
1686
1687         mutex_lock(&c->ec_stripe_new_lock);
1688         list_for_each_entry(s, &c->ec_stripe_new_list, list) {
1689                 pr_buf(out, "\tin flight: blocks %u+%u pin %u\n",
1690                        s->nr_data, s->nr_parity,
1691                        atomic_read(&s->pin));
1692         }
1693         mutex_unlock(&c->ec_stripe_new_lock);
1694 }
1695
1696 void bch2_fs_ec_exit(struct bch_fs *c)
1697 {
1698         struct ec_stripe_head *h;
1699
1700         while (1) {
1701                 mutex_lock(&c->ec_stripe_head_lock);
1702                 h = list_first_entry_or_null(&c->ec_stripe_head_list,
1703                                              struct ec_stripe_head, list);
1704                 if (h)
1705                         list_del(&h->list);
1706                 mutex_unlock(&c->ec_stripe_head_lock);
1707                 if (!h)
1708                         break;
1709
1710                 BUG_ON(h->s);
1711                 kfree(h);
1712         }
1713
1714         BUG_ON(!list_empty(&c->ec_stripe_new_list));
1715
1716         free_heap(&c->ec_stripes_heap);
1717         genradix_free(&c->stripes);
1718         bioset_exit(&c->ec_bioset);
1719 }
1720
1721 int bch2_fs_ec_init(struct bch_fs *c)
1722 {
1723         INIT_WORK(&c->ec_stripe_create_work, ec_stripe_create_work);
1724         INIT_WORK(&c->ec_stripe_delete_work, ec_stripe_delete_work);
1725
1726         return bioset_init(&c->ec_bioset, 1, offsetof(struct ec_bio, bio),
1727                            BIOSET_NEED_BVECS);
1728 }