fs/bcachefs/ec.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 /* erasure coding */
   4
   5 #include "bcachefs.h"
   6 #include "alloc_background.h"
   7 #include "alloc_foreground.h"
   8 #include "backpointers.h"
   9 #include "bkey_buf.h"
  10 #include "bset.h"
  11 #include "btree_gc.h"
  12 #include "btree_update.h"
  13 #include "btree_write_buffer.h"
  14 #include "buckets.h"
  15 #include "checksum.h"
  16 #include "disk_groups.h"
  17 #include "ec.h"
  18 #include "error.h"
  19 #include "io_read.h"
  20 #include "keylist.h"
  21 #include "recovery.h"
  22 #include "replicas.h"
  23 #include "super-io.h"
  24 #include "util.h"
  25
  26 #include <linux/sort.h>
  27
  28 #ifdef __KERNEL__
  29
  30 #include <linux/raid/pq.h>
  31 #include <linux/raid/xor.h>
  32
  33 static void raid5_recov(unsigned disks, unsigned failed_idx,
  34                         size_t size, void **data)
  35 {
  36         unsigned i = 2, nr;
  37
  38         BUG_ON(failed_idx >= disks);
  39
  40         swap(data[0], data[failed_idx]);
  41         memcpy(data[0], data[1], size);
  42
  43         while (i < disks) {
  44                 nr = min_t(unsigned, disks - i, MAX_XOR_BLOCKS);
  45                 xor_blocks(nr, size, data[0], data + i);
  46                 i += nr;
  47         }
  48
  49         swap(data[0], data[failed_idx]);
  50 }
  51
  52 static void raid_gen(int nd, int np, size_t size, void **v)
  53 {
  54         if (np >= 1)
  55                 raid5_recov(nd + np, nd, size, v);
  56         if (np >= 2)
  57                 raid6_call.gen_syndrome(nd + np, size, v);
  58         BUG_ON(np > 2);
  59 }
  60
  61 static void raid_rec(int nr, int *ir, int nd, int np, size_t size, void **v)
  62 {
  63         switch (nr) {
  64         case 0:
  65                 break;
  66         case 1:
  67                 if (ir[0] < nd + 1)
  68                         raid5_recov(nd + 1, ir[0], size, v);
  69                 else
  70                         raid6_call.gen_syndrome(nd + np, size, v);
  71                 break;
  72         case 2:
  73                 if (ir[1] < nd) {
  74                         /* data+data failure. */
  75                         raid6_2data_recov(nd + np, size, ir[0], ir[1], v);
  76                 } else if (ir[0] < nd) {
  77                         /* data + p/q failure */
  78
  79                         if (ir[1] == nd) /* data + p failure */
  80                                 raid6_datap_recov(nd + np, size, ir[0], v);
  81                         else { /* data + q failure */
  82                                 raid5_recov(nd + 1, ir[0], size, v);
  83                                 raid6_call.gen_syndrome(nd + np, size, v);
  84                         }
  85                 } else {
  86                         raid_gen(nd, np, size, v);
  87                 }
  88                 break;
  89         default:
  90                 BUG();
  91         }
  92 }
  93
  94 #else
  95
  96 #include <raid/raid.h>
  97
  98 #endif
  99
 100 struct ec_bio {
 101         struct bch_dev          *ca;
 102         struct ec_stripe_buf    *buf;
 103         size_t                  idx;
 104         struct bio              bio;
 105 };
 106
 107 /* Stripes btree keys: */
 108
 109 int bch2_stripe_invalid(struct bch_fs *c, struct bkey_s_c k,
 110                         enum bch_validate_flags flags,
 111                         struct printbuf *err)
 112 {
 113         const struct bch_stripe *s = bkey_s_c_to_stripe(k).v;
 114         int ret = 0;
 115
 116         bkey_fsck_err_on(bkey_eq(k.k->p, POS_MIN) ||
 117                          bpos_gt(k.k->p, POS(0, U32_MAX)), c, err,
 118                          stripe_pos_bad,
 119                          "stripe at bad pos");
 120
 121         bkey_fsck_err_on(bkey_val_u64s(k.k) < stripe_val_u64s(s), c, err,
 122                          stripe_val_size_bad,
 123                          "incorrect value size (%zu < %u)",
 124                          bkey_val_u64s(k.k), stripe_val_u64s(s));
 125
 126         ret = bch2_bkey_ptrs_invalid(c, k, flags, err);
 127 fsck_err:
 128         return ret;
 129 }
 130
 131 void bch2_stripe_to_text(struct printbuf *out, struct bch_fs *c,
 132                          struct bkey_s_c k)
 133 {
 134         const struct bch_stripe *sp = bkey_s_c_to_stripe(k).v;
 135         struct bch_stripe s = {};
 136
 137         memcpy(&s, sp, min(sizeof(s), bkey_val_bytes(k.k)));
 138
 139         unsigned nr_data = s.nr_blocks - s.nr_redundant;
 140
 141         prt_printf(out, "algo %u sectors %u blocks %u:%u csum ",
 142                    s.algorithm,
 143                    le16_to_cpu(s.sectors),
 144                    nr_data,
 145                    s.nr_redundant);
 146         bch2_prt_csum_type(out, s.csum_type);
 147         prt_printf(out, " gran %u", 1U << s.csum_granularity_bits);
 148
 149         for (unsigned i = 0; i < s.nr_blocks; i++) {
 150                 const struct bch_extent_ptr *ptr = sp->ptrs + i;
 151
 152                 if ((void *) ptr >= bkey_val_end(k))
 153                         break;
 154
 155                 bch2_extent_ptr_to_text(out, c, ptr);
 156
 157                 if (s.csum_type < BCH_CSUM_NR &&
 158                     i < nr_data &&
 159                     stripe_blockcount_offset(&s, i) < bkey_val_bytes(k.k))
 160                         prt_printf(out,  "#%u", stripe_blockcount_get(sp, i));
 161         }
 162 }
 163
 164 /* Triggers: */
 165
 166 static int __mark_stripe_bucket(struct btree_trans *trans,
 167                                 struct bch_dev *ca,
 168                                 struct bkey_s_c_stripe s,
 169                                 unsigned ptr_idx, bool deleting,
 170                                 struct bpos bucket,
 171                                 struct bch_alloc_v4 *a,
 172                                 enum btree_iter_update_trigger_flags flags)
 173 {
 174         const struct bch_extent_ptr *ptr = s.v->ptrs + ptr_idx;
 175         unsigned nr_data = s.v->nr_blocks - s.v->nr_redundant;
 176         bool parity = ptr_idx >= nr_data;
 177         enum bch_data_type data_type = parity ? BCH_DATA_parity : BCH_DATA_stripe;
 178         s64 sectors = parity ? le16_to_cpu(s.v->sectors) : 0;
 179         struct printbuf buf = PRINTBUF;
 180         int ret = 0;
 181
 182         struct bch_fs *c = trans->c;
 183         if (deleting)
 184                 sectors = -sectors;
 185
 186         if (!deleting) {
 187                 if (bch2_trans_inconsistent_on(a->stripe ||
 188                                                a->stripe_redundancy, trans,
 189                                 "bucket %llu:%llu gen %u data type %s dirty_sectors %u: multiple stripes using same bucket (%u, %llu)\n%s",
 190                                 bucket.inode, bucket.offset, a->gen,
 191                                 bch2_data_type_str(a->data_type),
 192                                 a->dirty_sectors,
 193                                 a->stripe, s.k->p.offset,
 194                                 (bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
 195                         ret = -EIO;
 196                         goto err;
 197                 }
 198
 199                 if (bch2_trans_inconsistent_on(parity && bch2_bucket_sectors_total(*a), trans,
 200                                 "bucket %llu:%llu gen %u data type %s dirty_sectors %u cached_sectors %u: data already in parity bucket\n%s",
 201                                 bucket.inode, bucket.offset, a->gen,
 202                                 bch2_data_type_str(a->data_type),
 203                                 a->dirty_sectors,
 204                                 a->cached_sectors,
 205                                 (bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
 206                         ret = -EIO;
 207                         goto err;
 208                 }
 209         } else {
 210                 if (bch2_trans_inconsistent_on(a->stripe != s.k->p.offset ||
 211                                                a->stripe_redundancy != s.v->nr_redundant, trans,
 212                                 "bucket %llu:%llu gen %u: not marked as stripe when deleting stripe (got %u)\n%s",
 213                                 bucket.inode, bucket.offset, a->gen,
 214                                 a->stripe,
 215                                 (bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
 216                         ret = -EIO;
 217                         goto err;
 218                 }
 219
 220                 if (bch2_trans_inconsistent_on(a->data_type != data_type, trans,
 221                                 "bucket %llu:%llu gen %u data type %s: wrong data type when stripe, should be %s\n%s",
 222                                 bucket.inode, bucket.offset, a->gen,
 223                                 bch2_data_type_str(a->data_type),
 224                                 bch2_data_type_str(data_type),
 225                                 (bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
 226                         ret = -EIO;
 227                         goto err;
 228                 }
 229
 230                 if (bch2_trans_inconsistent_on(parity &&
 231                                                (a->dirty_sectors != -sectors ||
 232                                                 a->cached_sectors), trans,
 233                                 "bucket %llu:%llu gen %u dirty_sectors %u cached_sectors %u: wrong sectors when deleting parity block of stripe\n%s",
 234                                 bucket.inode, bucket.offset, a->gen,
 235                                 a->dirty_sectors,
 236                                 a->cached_sectors,
 237                                 (bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
 238                         ret = -EIO;
 239                         goto err;
 240                 }
 241         }
 242
 243         if (sectors) {
 244                 ret = bch2_bucket_ref_update(trans, ca, s.s_c, ptr, sectors, data_type,
 245                                              a->gen, a->data_type, &a->dirty_sectors);
 246                 if (ret)
 247                         goto err;
 248         }
 249
 250         if (!deleting) {
 251                 a->stripe               = s.k->p.offset;
 252                 a->stripe_redundancy    = s.v->nr_redundant;
 253         } else {
 254                 a->stripe               = 0;
 255                 a->stripe_redundancy    = 0;
 256         }
 257
 258         alloc_data_type_set(a, data_type);
 259 err:
 260         printbuf_exit(&buf);
 261         return ret;
 262 }
 263
 264 static int mark_stripe_bucket(struct btree_trans *trans,
 265                               struct bkey_s_c_stripe s,
 266                               unsigned ptr_idx, bool deleting,
 267                               enum btree_iter_update_trigger_flags flags)
 268 {
 269         struct bch_fs *c = trans->c;
 270         const struct bch_extent_ptr *ptr = s.v->ptrs + ptr_idx;
 271         int ret = 0;
 272
 273         struct bch_dev *ca = bch2_dev_tryget(c, ptr->dev);
 274         if (unlikely(!ca)) {
 275                 if (!(flags & BTREE_TRIGGER_overwrite))
 276                         ret = -EIO;
 277                 goto err;
 278         }
 279
 280         struct bpos bucket = PTR_BUCKET_POS(ca, ptr);
 281
 282         if (flags & BTREE_TRIGGER_transactional) {
 283                 struct bkey_i_alloc_v4 *a =
 284                         bch2_trans_start_alloc_update(trans, bucket);
 285                 ret = PTR_ERR_OR_ZERO(a) ?:
 286                         __mark_stripe_bucket(trans, ca, s, ptr_idx, deleting, bucket, &a->v, flags);
 287         }
 288
 289         if (flags & BTREE_TRIGGER_gc) {
 290                 percpu_down_read(&c->mark_lock);
 291                 struct bucket *g = gc_bucket(ca, bucket.offset);
 292                 bucket_lock(g);
 293                 struct bch_alloc_v4 old = bucket_m_to_alloc(*g), new = old;
 294                 ret = __mark_stripe_bucket(trans, ca, s, ptr_idx, deleting, bucket, &new, flags);
 295                 if (!ret) {
 296                         alloc_to_bucket(g, new);
 297                         bch2_dev_usage_update(c, ca, &old, &new, 0, true);
 298                 }
 299                 bucket_unlock(g);
 300                 percpu_up_read(&c->mark_lock);
 301         }
 302 err:
 303         bch2_dev_put(ca);
 304         return ret;
 305 }
 306
 307 static int mark_stripe_buckets(struct btree_trans *trans,
 308                                struct bkey_s_c old, struct bkey_s_c new,
 309                                enum btree_iter_update_trigger_flags flags)
 310 {
 311         const struct bch_stripe *old_s = old.k->type == KEY_TYPE_stripe
 312                 ? bkey_s_c_to_stripe(old).v : NULL;
 313         const struct bch_stripe *new_s = new.k->type == KEY_TYPE_stripe
 314                 ? bkey_s_c_to_stripe(new).v : NULL;
 315
 316         BUG_ON(old_s && new_s && old_s->nr_blocks != new_s->nr_blocks);
 317
 318         unsigned nr_blocks = new_s ? new_s->nr_blocks : old_s->nr_blocks;
 319
 320         for (unsigned i = 0; i < nr_blocks; i++) {
 321                 if (new_s && old_s &&
 322                     !memcmp(&new_s->ptrs[i],
 323                             &old_s->ptrs[i],
 324                             sizeof(new_s->ptrs[i])))
 325                         continue;
 326
 327                 if (new_s) {
 328                         int ret = mark_stripe_bucket(trans,
 329                                         bkey_s_c_to_stripe(new), i, false, flags);
 330                         if (ret)
 331                                 return ret;
 332                 }
 333
 334                 if (old_s) {
 335                         int ret = mark_stripe_bucket(trans,
 336                                         bkey_s_c_to_stripe(old), i, true, flags);
 337                         if (ret)
 338                                 return ret;
 339                 }
 340         }
 341
 342         return 0;
 343 }
 344
 345 int bch2_trigger_stripe(struct btree_trans *trans,
 346                         enum btree_id btree, unsigned level,
 347                         struct bkey_s_c old, struct bkey_s _new,
 348                         enum btree_iter_update_trigger_flags flags)
 349 {
 350         struct bkey_s_c new = _new.s_c;
 351         struct bch_fs *c = trans->c;
 352         u64 idx = new.k->p.offset;
 353         const struct bch_stripe *old_s = old.k->type == KEY_TYPE_stripe
 354                 ? bkey_s_c_to_stripe(old).v : NULL;
 355         const struct bch_stripe *new_s = new.k->type == KEY_TYPE_stripe
 356                 ? bkey_s_c_to_stripe(new).v : NULL;
 357
 358         if (unlikely(flags & BTREE_TRIGGER_check_repair))
 359                 return bch2_check_fix_ptrs(trans, btree, level, _new.s_c, flags);
 360
 361         if (flags & BTREE_TRIGGER_transactional) {
 362                 /*
 363                  * If the pointers aren't changing, we don't need to do anything:
 364                  */
 365                 if (new_s && old_s &&
 366                     new_s->nr_blocks    == old_s->nr_blocks &&
 367                     new_s->nr_redundant == old_s->nr_redundant &&
 368                     !memcmp(old_s->ptrs, new_s->ptrs,
 369                             new_s->nr_blocks * sizeof(struct bch_extent_ptr)))
 370                         return 0;
 371
 372                 BUG_ON(new_s && old_s &&
 373                        (new_s->nr_blocks        != old_s->nr_blocks ||
 374                         new_s->nr_redundant     != old_s->nr_redundant));
 375
 376                 if (new_s) {
 377                         s64 sectors = le16_to_cpu(new_s->sectors);
 378
 379                         struct bch_replicas_padded r;
 380                         bch2_bkey_to_replicas(&r.e, new);
 381                         int ret = bch2_update_replicas_list(trans, &r.e, sectors * new_s->nr_redundant);
 382                         if (ret)
 383                                 return ret;
 384                 }
 385
 386                 if (old_s) {
 387                         s64 sectors = -((s64) le16_to_cpu(old_s->sectors));
 388
 389                         struct bch_replicas_padded r;
 390                         bch2_bkey_to_replicas(&r.e, old);
 391                         int ret = bch2_update_replicas_list(trans, &r.e, sectors * old_s->nr_redundant);
 392                         if (ret)
 393                                 return ret;
 394                 }
 395
 396                 int ret = mark_stripe_buckets(trans, old, new, flags);
 397                 if (ret)
 398                         return ret;
 399         }
 400
 401         if (flags & BTREE_TRIGGER_atomic) {
 402                 struct stripe *m = genradix_ptr(&c->stripes, idx);
 403
 404                 if (!m) {
 405                         struct printbuf buf1 = PRINTBUF;
 406                         struct printbuf buf2 = PRINTBUF;
 407
 408                         bch2_bkey_val_to_text(&buf1, c, old);
 409                         bch2_bkey_val_to_text(&buf2, c, new);
 410                         bch_err_ratelimited(c, "error marking nonexistent stripe %llu while marking\n"
 411                                             "old %s\n"
 412                                             "new %s", idx, buf1.buf, buf2.buf);
 413                         printbuf_exit(&buf2);
 414                         printbuf_exit(&buf1);
 415                         bch2_inconsistent_error(c);
 416                         return -1;
 417                 }
 418
 419                 if (!new_s) {
 420                         bch2_stripes_heap_del(c, m, idx);
 421
 422                         memset(m, 0, sizeof(*m));
 423                 } else {
 424                         m->sectors      = le16_to_cpu(new_s->sectors);
 425                         m->algorithm    = new_s->algorithm;
 426                         m->nr_blocks    = new_s->nr_blocks;
 427                         m->nr_redundant = new_s->nr_redundant;
 428                         m->blocks_nonempty = 0;
 429
 430                         for (unsigned i = 0; i < new_s->nr_blocks; i++)
 431                                 m->blocks_nonempty += !!stripe_blockcount_get(new_s, i);
 432
 433                         if (!old_s)
 434                                 bch2_stripes_heap_insert(c, m, idx);
 435                         else
 436                                 bch2_stripes_heap_update(c, m, idx);
 437                 }
 438         }
 439
 440         if (flags & BTREE_TRIGGER_gc) {
 441                 struct gc_stripe *m =
 442                         genradix_ptr_alloc(&c->gc_stripes, idx, GFP_KERNEL);
 443
 444                 if (!m) {
 445                         bch_err(c, "error allocating memory for gc_stripes, idx %llu",
 446                                 idx);
 447                         return -BCH_ERR_ENOMEM_mark_stripe;
 448                 }
 449                 /*
 450                  * This will be wrong when we bring back runtime gc: we should
 451                  * be unmarking the old key and then marking the new key
 452                  */
 453                 m->alive        = true;
 454                 m->sectors      = le16_to_cpu(new_s->sectors);
 455                 m->nr_blocks    = new_s->nr_blocks;
 456                 m->nr_redundant = new_s->nr_redundant;
 457
 458                 for (unsigned i = 0; i < new_s->nr_blocks; i++)
 459                         m->ptrs[i] = new_s->ptrs[i];
 460
 461                 bch2_bkey_to_replicas(&m->r.e, new);
 462
 463                 /*
 464                  * gc recalculates this field from stripe ptr
 465                  * references:
 466                  */
 467                 memset(m->block_sectors, 0, sizeof(m->block_sectors));
 468
 469                 int ret = mark_stripe_buckets(trans, old, new, flags);
 470                 if (ret)
 471                         return ret;
 472
 473                 ret = bch2_update_replicas(c, new, &m->r.e,
 474                                       ((s64) m->sectors * m->nr_redundant),
 475                                       0, true);
 476                 if (ret) {
 477                         struct printbuf buf = PRINTBUF;
 478
 479                         bch2_bkey_val_to_text(&buf, c, new);
 480                         bch2_fs_fatal_error(c, ": no replicas entry for %s", buf.buf);
 481                         printbuf_exit(&buf);
 482                         return ret;
 483                 }
 484         }
 485
 486         return 0;
 487 }
 488
 489 /* returns blocknr in stripe that we matched: */
 490 static const struct bch_extent_ptr *bkey_matches_stripe(struct bch_stripe *s,
 491                                                 struct bkey_s_c k, unsigned *block)
 492 {
 493         struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
 494         unsigned i, nr_data = s->nr_blocks - s->nr_redundant;
 495
 496         bkey_for_each_ptr(ptrs, ptr)
 497                 for (i = 0; i < nr_data; i++)
 498                         if (__bch2_ptr_matches_stripe(&s->ptrs[i], ptr,
 499                                                       le16_to_cpu(s->sectors))) {
 500                                 *block = i;
 501                                 return ptr;
 502                         }
 503
 504         return NULL;
 505 }
 506
 507 static bool extent_has_stripe_ptr(struct bkey_s_c k, u64 idx)
 508 {
 509         switch (k.k->type) {
 510         case KEY_TYPE_extent: {
 511                 struct bkey_s_c_extent e = bkey_s_c_to_extent(k);
 512                 const union bch_extent_entry *entry;
 513
 514                 extent_for_each_entry(e, entry)
 515                         if (extent_entry_type(entry) ==
 516                             BCH_EXTENT_ENTRY_stripe_ptr &&
 517                             entry->stripe_ptr.idx == idx)
 518                                 return true;
 519
 520                 break;
 521         }
 522         }
 523
 524         return false;
 525 }
 526
 527 /* Stripe bufs: */
 528
 529 static void ec_stripe_buf_exit(struct ec_stripe_buf *buf)
 530 {
 531         if (buf->key.k.type == KEY_TYPE_stripe) {
 532                 struct bkey_i_stripe *s = bkey_i_to_stripe(&buf->key);
 533                 unsigned i;
 534
 535                 for (i = 0; i < s->v.nr_blocks; i++) {
 536                         kvfree(buf->data[i]);
 537                         buf->data[i] = NULL;
 538                 }
 539         }
 540 }
 541
 542 /* XXX: this is a non-mempoolified memory allocation: */
 543 static int ec_stripe_buf_init(struct ec_stripe_buf *buf,
 544                               unsigned offset, unsigned size)
 545 {
 546         struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 547         unsigned csum_granularity = 1U << v->csum_granularity_bits;
 548         unsigned end = offset + size;
 549         unsigned i;
 550
 551         BUG_ON(end > le16_to_cpu(v->sectors));
 552
 553         offset  = round_down(offset, csum_granularity);
 554         end     = min_t(unsigned, le16_to_cpu(v->sectors),
 555                         round_up(end, csum_granularity));
 556
 557         buf->offset     = offset;
 558         buf->size       = end - offset;
 559
 560         memset(buf->valid, 0xFF, sizeof(buf->valid));
 561
 562         for (i = 0; i < v->nr_blocks; i++) {
 563                 buf->data[i] = kvmalloc(buf->size << 9, GFP_KERNEL);
 564                 if (!buf->data[i])
 565                         goto err;
 566         }
 567
 568         return 0;
 569 err:
 570         ec_stripe_buf_exit(buf);
 571         return -BCH_ERR_ENOMEM_stripe_buf;
 572 }
 573
 574 /* Checksumming: */
 575
 576 static struct bch_csum ec_block_checksum(struct ec_stripe_buf *buf,
 577                                          unsigned block, unsigned offset)
 578 {
 579         struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 580         unsigned csum_granularity = 1 << v->csum_granularity_bits;
 581         unsigned end = buf->offset + buf->size;
 582         unsigned len = min(csum_granularity, end - offset);
 583
 584         BUG_ON(offset >= end);
 585         BUG_ON(offset <  buf->offset);
 586         BUG_ON(offset & (csum_granularity - 1));
 587         BUG_ON(offset + len != le16_to_cpu(v->sectors) &&
 588                (len & (csum_granularity - 1)));
 589
 590         return bch2_checksum(NULL, v->csum_type,
 591                              null_nonce(),
 592                              buf->data[block] + ((offset - buf->offset) << 9),
 593                              len << 9);
 594 }
 595
 596 static void ec_generate_checksums(struct ec_stripe_buf *buf)
 597 {
 598         struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 599         unsigned i, j, csums_per_device = stripe_csums_per_device(v);
 600
 601         if (!v->csum_type)
 602                 return;
 603
 604         BUG_ON(buf->offset);
 605         BUG_ON(buf->size != le16_to_cpu(v->sectors));
 606
 607         for (i = 0; i < v->nr_blocks; i++)
 608                 for (j = 0; j < csums_per_device; j++)
 609                         stripe_csum_set(v, i, j,
 610                                 ec_block_checksum(buf, i, j << v->csum_granularity_bits));
 611 }
 612
 613 static void ec_validate_checksums(struct bch_fs *c, struct ec_stripe_buf *buf)
 614 {
 615         struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 616         unsigned csum_granularity = 1 << v->csum_granularity_bits;
 617         unsigned i;
 618
 619         if (!v->csum_type)
 620                 return;
 621
 622         for (i = 0; i < v->nr_blocks; i++) {
 623                 unsigned offset = buf->offset;
 624                 unsigned end = buf->offset + buf->size;
 625
 626                 if (!test_bit(i, buf->valid))
 627                         continue;
 628
 629                 while (offset < end) {
 630                         unsigned j = offset >> v->csum_granularity_bits;
 631                         unsigned len = min(csum_granularity, end - offset);
 632                         struct bch_csum want = stripe_csum_get(v, i, j);
 633                         struct bch_csum got = ec_block_checksum(buf, i, offset);
 634
 635                         if (bch2_crc_cmp(want, got)) {
 636                                 struct bch_dev *ca = bch2_dev_tryget(c, v->ptrs[i].dev);
 637                                 if (ca) {
 638                                         struct printbuf err = PRINTBUF;
 639
 640                                         prt_str(&err, "stripe ");
 641                                         bch2_csum_err_msg(&err, v->csum_type, want, got);
 642                                         prt_printf(&err, "  for %ps at %u of\n  ", (void *) _RET_IP_, i);
 643                                         bch2_bkey_val_to_text(&err, c, bkey_i_to_s_c(&buf->key));
 644                                         bch_err_ratelimited(ca, "%s", err.buf);
 645                                         printbuf_exit(&err);
 646
 647                                         bch2_io_error(ca, BCH_MEMBER_ERROR_checksum);
 648                                 }
 649
 650                                 clear_bit(i, buf->valid);
 651                                 break;
 652                         }
 653
 654                         offset += len;
 655                 }
 656         }
 657 }
 658
 659 /* Erasure coding: */
 660
 661 static void ec_generate_ec(struct ec_stripe_buf *buf)
 662 {
 663         struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 664         unsigned nr_data = v->nr_blocks - v->nr_redundant;
 665         unsigned bytes = le16_to_cpu(v->sectors) << 9;
 666
 667         raid_gen(nr_data, v->nr_redundant, bytes, buf->data);
 668 }
 669
 670 static unsigned ec_nr_failed(struct ec_stripe_buf *buf)
 671 {
 672         struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 673
 674         return v->nr_blocks - bitmap_weight(buf->valid, v->nr_blocks);
 675 }
 676
 677 static int ec_do_recov(struct bch_fs *c, struct ec_stripe_buf *buf)
 678 {
 679         struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 680         unsigned i, failed[BCH_BKEY_PTRS_MAX], nr_failed = 0;
 681         unsigned nr_data = v->nr_blocks - v->nr_redundant;
 682         unsigned bytes = buf->size << 9;
 683
 684         if (ec_nr_failed(buf) > v->nr_redundant) {
 685                 bch_err_ratelimited(c,
 686                         "error doing reconstruct read: unable to read enough blocks");
 687                 return -1;
 688         }
 689
 690         for (i = 0; i < nr_data; i++)
 691                 if (!test_bit(i, buf->valid))
 692                         failed[nr_failed++] = i;
 693
 694         raid_rec(nr_failed, failed, nr_data, v->nr_redundant, bytes, buf->data);
 695         return 0;
 696 }
 697
 698 /* IO: */
 699
 700 static void ec_block_endio(struct bio *bio)
 701 {
 702         struct ec_bio *ec_bio = container_of(bio, struct ec_bio, bio);
 703         struct bch_stripe *v = &bkey_i_to_stripe(&ec_bio->buf->key)->v;
 704         struct bch_extent_ptr *ptr = &v->ptrs[ec_bio->idx];
 705         struct bch_dev *ca = ec_bio->ca;
 706         struct closure *cl = bio->bi_private;
 707
 708         if (bch2_dev_io_err_on(bio->bi_status, ca,
 709                                bio_data_dir(bio)
 710                                ? BCH_MEMBER_ERROR_write
 711                                : BCH_MEMBER_ERROR_read,
 712                                "erasure coding %s error: %s",
 713                                bio_data_dir(bio) ? "write" : "read",
 714                                bch2_blk_status_to_str(bio->bi_status)))
 715                 clear_bit(ec_bio->idx, ec_bio->buf->valid);
 716
 717         if (dev_ptr_stale(ca, ptr)) {
 718                 bch_err_ratelimited(ca->fs,
 719                                     "error %s stripe: stale pointer after io",
 720                                     bio_data_dir(bio) == READ ? "reading from" : "writing to");
 721                 clear_bit(ec_bio->idx, ec_bio->buf->valid);
 722         }
 723
 724         bio_put(&ec_bio->bio);
 725         percpu_ref_put(&ca->io_ref);
 726         closure_put(cl);
 727 }
 728
 729 static void ec_block_io(struct bch_fs *c, struct ec_stripe_buf *buf,
 730                         blk_opf_t opf, unsigned idx, struct closure *cl)
 731 {
 732         struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 733         unsigned offset = 0, bytes = buf->size << 9;
 734         struct bch_extent_ptr *ptr = &v->ptrs[idx];
 735         enum bch_data_type data_type = idx < v->nr_blocks - v->nr_redundant
 736                 ? BCH_DATA_user
 737                 : BCH_DATA_parity;
 738         int rw = op_is_write(opf);
 739
 740         struct bch_dev *ca = bch2_dev_get_ioref(c, ptr->dev, rw);
 741         if (!ca) {
 742                 clear_bit(idx, buf->valid);
 743                 return;
 744         }
 745
 746         if (dev_ptr_stale(ca, ptr)) {
 747                 bch_err_ratelimited(c,
 748                                     "error %s stripe: stale pointer",
 749                                     rw == READ ? "reading from" : "writing to");
 750                 clear_bit(idx, buf->valid);
 751                 return;
 752         }
 753
 754
 755         this_cpu_add(ca->io_done->sectors[rw][data_type], buf->size);
 756
 757         while (offset < bytes) {
 758                 unsigned nr_iovecs = min_t(size_t, BIO_MAX_VECS,
 759                                            DIV_ROUND_UP(bytes, PAGE_SIZE));
 760                 unsigned b = min_t(size_t, bytes - offset,
 761                                    nr_iovecs << PAGE_SHIFT);
 762                 struct ec_bio *ec_bio;
 763
 764                 ec_bio = container_of(bio_alloc_bioset(ca->disk_sb.bdev,
 765                                                        nr_iovecs,
 766                                                        opf,
 767                                                        GFP_KERNEL,
 768                                                        &c->ec_bioset),
 769                                       struct ec_bio, bio);
 770
 771                 ec_bio->ca                      = ca;
 772                 ec_bio->buf                     = buf;
 773                 ec_bio->idx                     = idx;
 774
 775                 ec_bio->bio.bi_iter.bi_sector   = ptr->offset + buf->offset + (offset >> 9);
 776                 ec_bio->bio.bi_end_io           = ec_block_endio;
 777                 ec_bio->bio.bi_private          = cl;
 778
 779                 bch2_bio_map(&ec_bio->bio, buf->data[idx] + offset, b);
 780
 781                 closure_get(cl);
 782                 percpu_ref_get(&ca->io_ref);
 783
 784                 submit_bio(&ec_bio->bio);
 785
 786                 offset += b;
 787         }
 788
 789         percpu_ref_put(&ca->io_ref);
 790 }
 791
 792 static int get_stripe_key_trans(struct btree_trans *trans, u64 idx,
 793                                 struct ec_stripe_buf *stripe)
 794 {
 795         struct btree_iter iter;
 796         struct bkey_s_c k;
 797         int ret;
 798
 799         k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_stripes,
 800                                POS(0, idx), BTREE_ITER_slots);
 801         ret = bkey_err(k);
 802         if (ret)
 803                 goto err;
 804         if (k.k->type != KEY_TYPE_stripe) {
 805                 ret = -ENOENT;
 806                 goto err;
 807         }
 808         bkey_reassemble(&stripe->key, k);
 809 err:
 810         bch2_trans_iter_exit(trans, &iter);
 811         return ret;
 812 }
 813
 814 /* recovery read path: */
 815 int bch2_ec_read_extent(struct btree_trans *trans, struct bch_read_bio *rbio)
 816 {
 817         struct bch_fs *c = trans->c;
 818         struct ec_stripe_buf *buf;
 819         struct closure cl;
 820         struct bch_stripe *v;
 821         unsigned i, offset;
 822         int ret = 0;
 823
 824         closure_init_stack(&cl);
 825
 826         BUG_ON(!rbio->pick.has_ec);
 827
 828         buf = kzalloc(sizeof(*buf), GFP_NOFS);
 829         if (!buf)
 830                 return -BCH_ERR_ENOMEM_ec_read_extent;
 831
 832         ret = lockrestart_do(trans, get_stripe_key_trans(trans, rbio->pick.ec.idx, buf));
 833         if (ret) {
 834                 bch_err_ratelimited(c,
 835                         "error doing reconstruct read: error %i looking up stripe", ret);
 836                 kfree(buf);
 837                 return -EIO;
 838         }
 839
 840         v = &bkey_i_to_stripe(&buf->key)->v;
 841
 842         if (!bch2_ptr_matches_stripe(v, rbio->pick)) {
 843                 bch_err_ratelimited(c,
 844                         "error doing reconstruct read: pointer doesn't match stripe");
 845                 ret = -EIO;
 846                 goto err;
 847         }
 848
 849         offset = rbio->bio.bi_iter.bi_sector - v->ptrs[rbio->pick.ec.block].offset;
 850         if (offset + bio_sectors(&rbio->bio) > le16_to_cpu(v->sectors)) {
 851                 bch_err_ratelimited(c,
 852                         "error doing reconstruct read: read is bigger than stripe");
 853                 ret = -EIO;
 854                 goto err;
 855         }
 856
 857         ret = ec_stripe_buf_init(buf, offset, bio_sectors(&rbio->bio));
 858         if (ret)
 859                 goto err;
 860
 861         for (i = 0; i < v->nr_blocks; i++)
 862                 ec_block_io(c, buf, REQ_OP_READ, i, &cl);
 863
 864         closure_sync(&cl);
 865
 866         if (ec_nr_failed(buf) > v->nr_redundant) {
 867                 bch_err_ratelimited(c,
 868                         "error doing reconstruct read: unable to read enough blocks");
 869                 ret = -EIO;
 870                 goto err;
 871         }
 872
 873         ec_validate_checksums(c, buf);
 874
 875         ret = ec_do_recov(c, buf);
 876         if (ret)
 877                 goto err;
 878
 879         memcpy_to_bio(&rbio->bio, rbio->bio.bi_iter,
 880                       buf->data[rbio->pick.ec.block] + ((offset - buf->offset) << 9));
 881 err:
 882         ec_stripe_buf_exit(buf);
 883         kfree(buf);
 884         return ret;
 885 }
 886
 887 /* stripe bucket accounting: */
 888
 889 static int __ec_stripe_mem_alloc(struct bch_fs *c, size_t idx, gfp_t gfp)
 890 {
 891         ec_stripes_heap n, *h = &c->ec_stripes_heap;
 892
 893         if (idx >= h->size) {
 894                 if (!init_heap(&n, max(1024UL, roundup_pow_of_two(idx + 1)), gfp))
 895                         return -BCH_ERR_ENOMEM_ec_stripe_mem_alloc;
 896
 897                 mutex_lock(&c->ec_stripes_heap_lock);
 898                 if (n.size > h->size) {
 899                         memcpy(n.data, h->data, h->used * sizeof(h->data[0]));
 900                         n.used = h->used;
 901                         swap(*h, n);
 902                 }
 903                 mutex_unlock(&c->ec_stripes_heap_lock);
 904
 905                 free_heap(&n);
 906         }
 907
 908         if (!genradix_ptr_alloc(&c->stripes, idx, gfp))
 909                 return -BCH_ERR_ENOMEM_ec_stripe_mem_alloc;
 910
 911         if (c->gc_pos.phase != GC_PHASE_NOT_RUNNING &&
 912             !genradix_ptr_alloc(&c->gc_stripes, idx, gfp))
 913                 return -BCH_ERR_ENOMEM_ec_stripe_mem_alloc;
 914
 915         return 0;
 916 }
 917
 918 static int ec_stripe_mem_alloc(struct btree_trans *trans,
 919                                struct btree_iter *iter)
 920 {
 921         return allocate_dropping_locks_errcode(trans,
 922                         __ec_stripe_mem_alloc(trans->c, iter->pos.offset, _gfp));
 923 }
 924
 925 /*
 926  * Hash table of open stripes:
 927  * Stripes that are being created or modified are kept in a hash table, so that
 928  * stripe deletion can skip them.
 929  */
 930
 931 static bool __bch2_stripe_is_open(struct bch_fs *c, u64 idx)
 932 {
 933         unsigned hash = hash_64(idx, ilog2(ARRAY_SIZE(c->ec_stripes_new)));
 934         struct ec_stripe_new *s;
 935
 936         hlist_for_each_entry(s, &c->ec_stripes_new[hash], hash)
 937                 if (s->idx == idx)
 938                         return true;
 939         return false;
 940 }
 941
 942 static bool bch2_stripe_is_open(struct bch_fs *c, u64 idx)
 943 {
 944         bool ret = false;
 945
 946         spin_lock(&c->ec_stripes_new_lock);
 947         ret = __bch2_stripe_is_open(c, idx);
 948         spin_unlock(&c->ec_stripes_new_lock);
 949
 950         return ret;
 951 }
 952
 953 static bool bch2_try_open_stripe(struct bch_fs *c,
 954                                  struct ec_stripe_new *s,
 955                                  u64 idx)
 956 {
 957         bool ret;
 958
 959         spin_lock(&c->ec_stripes_new_lock);
 960         ret = !__bch2_stripe_is_open(c, idx);
 961         if (ret) {
 962                 unsigned hash = hash_64(idx, ilog2(ARRAY_SIZE(c->ec_stripes_new)));
 963
 964                 s->idx = idx;
 965                 hlist_add_head(&s->hash, &c->ec_stripes_new[hash]);
 966         }
 967         spin_unlock(&c->ec_stripes_new_lock);
 968
 969         return ret;
 970 }
 971
 972 static void bch2_stripe_close(struct bch_fs *c, struct ec_stripe_new *s)
 973 {
 974         BUG_ON(!s->idx);
 975
 976         spin_lock(&c->ec_stripes_new_lock);
 977         hlist_del_init(&s->hash);
 978         spin_unlock(&c->ec_stripes_new_lock);
 979
 980         s->idx = 0;
 981 }
 982
 983 /* Heap of all existing stripes, ordered by blocks_nonempty */
 984
 985 static u64 stripe_idx_to_delete(struct bch_fs *c)
 986 {
 987         ec_stripes_heap *h = &c->ec_stripes_heap;
 988
 989         lockdep_assert_held(&c->ec_stripes_heap_lock);
 990
 991         if (h->used &&
 992             h->data[0].blocks_nonempty == 0 &&
 993             !bch2_stripe_is_open(c, h->data[0].idx))
 994                 return h->data[0].idx;
 995
 996         return 0;
 997 }
 998
 999 static inline int ec_stripes_heap_cmp(ec_stripes_heap *h,
1000                                       struct ec_stripe_heap_entry l,
1001                                       struct ec_stripe_heap_entry r)
1002 {
1003         return ((l.blocks_nonempty > r.blocks_nonempty) -
1004                 (l.blocks_nonempty < r.blocks_nonempty));
1005 }
1006
1007 static inline void ec_stripes_heap_set_backpointer(ec_stripes_heap *h,
1008                                                    size_t i)
1009 {
1010         struct bch_fs *c = container_of(h, struct bch_fs, ec_stripes_heap);
1011
1012         genradix_ptr(&c->stripes, h->data[i].idx)->heap_idx = i;
1013 }
1014
1015 static void heap_verify_backpointer(struct bch_fs *c, size_t idx)
1016 {
1017         ec_stripes_heap *h = &c->ec_stripes_heap;
1018         struct stripe *m = genradix_ptr(&c->stripes, idx);
1019
1020         BUG_ON(m->heap_idx >= h->used);
1021         BUG_ON(h->data[m->heap_idx].idx != idx);
1022 }
1023
1024 void bch2_stripes_heap_del(struct bch_fs *c,
1025                            struct stripe *m, size_t idx)
1026 {
1027         mutex_lock(&c->ec_stripes_heap_lock);
1028         heap_verify_backpointer(c, idx);
1029
1030         heap_del(&c->ec_stripes_heap, m->heap_idx,
1031                  ec_stripes_heap_cmp,
1032                  ec_stripes_heap_set_backpointer);
1033         mutex_unlock(&c->ec_stripes_heap_lock);
1034 }
1035
1036 void bch2_stripes_heap_insert(struct bch_fs *c,
1037                               struct stripe *m, size_t idx)
1038 {
1039         mutex_lock(&c->ec_stripes_heap_lock);
1040         BUG_ON(heap_full(&c->ec_stripes_heap));
1041
1042         heap_add(&c->ec_stripes_heap, ((struct ec_stripe_heap_entry) {
1043                         .idx = idx,
1044                         .blocks_nonempty = m->blocks_nonempty,
1045                 }),
1046                  ec_stripes_heap_cmp,
1047                  ec_stripes_heap_set_backpointer);
1048
1049         heap_verify_backpointer(c, idx);
1050         mutex_unlock(&c->ec_stripes_heap_lock);
1051 }
1052
1053 void bch2_stripes_heap_update(struct bch_fs *c,
1054                               struct stripe *m, size_t idx)
1055 {
1056         ec_stripes_heap *h = &c->ec_stripes_heap;
1057         bool do_deletes;
1058         size_t i;
1059
1060         mutex_lock(&c->ec_stripes_heap_lock);
1061         heap_verify_backpointer(c, idx);
1062
1063         h->data[m->heap_idx].blocks_nonempty = m->blocks_nonempty;
1064
1065         i = m->heap_idx;
1066         heap_sift_up(h,   i, ec_stripes_heap_cmp,
1067                      ec_stripes_heap_set_backpointer);
1068         heap_sift_down(h, i, ec_stripes_heap_cmp,
1069                        ec_stripes_heap_set_backpointer);
1070
1071         heap_verify_backpointer(c, idx);
1072
1073         do_deletes = stripe_idx_to_delete(c) != 0;
1074         mutex_unlock(&c->ec_stripes_heap_lock);
1075
1076         if (do_deletes)
1077                 bch2_do_stripe_deletes(c);
1078 }
1079
1080 /* stripe deletion */
1081
1082 static int ec_stripe_delete(struct btree_trans *trans, u64 idx)
1083 {
1084         struct bch_fs *c = trans->c;
1085         struct btree_iter iter;
1086         struct bkey_s_c k;
1087         struct bkey_s_c_stripe s;
1088         int ret;
1089
1090         k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_stripes, POS(0, idx),
1091                                BTREE_ITER_intent);
1092         ret = bkey_err(k);
1093         if (ret)
1094                 goto err;
1095
1096         if (k.k->type != KEY_TYPE_stripe) {
1097                 bch2_fs_inconsistent(c, "attempting to delete nonexistent stripe %llu", idx);
1098                 ret = -EINVAL;
1099                 goto err;
1100         }
1101
1102         s = bkey_s_c_to_stripe(k);
1103         for (unsigned i = 0; i < s.v->nr_blocks; i++)
1104                 if (stripe_blockcount_get(s.v, i)) {
1105                         struct printbuf buf = PRINTBUF;
1106
1107                         bch2_bkey_val_to_text(&buf, c, k);
1108                         bch2_fs_inconsistent(c, "attempting to delete nonempty stripe %s", buf.buf);
1109                         printbuf_exit(&buf);
1110                         ret = -EINVAL;
1111                         goto err;
1112                 }
1113
1114         ret = bch2_btree_delete_at(trans, &iter, 0);
1115 err:
1116         bch2_trans_iter_exit(trans, &iter);
1117         return ret;
1118 }
1119
1120 static void ec_stripe_delete_work(struct work_struct *work)
1121 {
1122         struct bch_fs *c =
1123                 container_of(work, struct bch_fs, ec_stripe_delete_work);
1124
1125         while (1) {
1126                 mutex_lock(&c->ec_stripes_heap_lock);
1127                 u64 idx = stripe_idx_to_delete(c);
1128                 mutex_unlock(&c->ec_stripes_heap_lock);
1129
1130                 if (!idx)
1131                         break;
1132
1133                 int ret = bch2_trans_do(c, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
1134                                         ec_stripe_delete(trans, idx));
1135                 bch_err_fn(c, ret);
1136                 if (ret)
1137                         break;
1138         }
1139
1140         bch2_write_ref_put(c, BCH_WRITE_REF_stripe_delete);
1141 }
1142
1143 void bch2_do_stripe_deletes(struct bch_fs *c)
1144 {
1145         if (bch2_write_ref_tryget(c, BCH_WRITE_REF_stripe_delete) &&
1146             !queue_work(c->write_ref_wq, &c->ec_stripe_delete_work))
1147                 bch2_write_ref_put(c, BCH_WRITE_REF_stripe_delete);
1148 }
1149
1150 /* stripe creation: */
1151
1152 static int ec_stripe_key_update(struct btree_trans *trans,
1153                                 struct bkey_i_stripe *new,
1154                                 bool create)
1155 {
1156         struct bch_fs *c = trans->c;
1157         struct btree_iter iter;
1158         struct bkey_s_c k;
1159         int ret;
1160
1161         k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_stripes,
1162                                new->k.p, BTREE_ITER_intent);
1163         ret = bkey_err(k);
1164         if (ret)
1165                 goto err;
1166
1167         if (k.k->type != (create ? KEY_TYPE_deleted : KEY_TYPE_stripe)) {
1168                 bch2_fs_inconsistent(c, "error %s stripe: got existing key type %s",
1169                                      create ? "creating" : "updating",
1170                                      bch2_bkey_types[k.k->type]);
1171                 ret = -EINVAL;
1172                 goto err;
1173         }
1174
1175         if (k.k->type == KEY_TYPE_stripe) {
1176                 const struct bch_stripe *old = bkey_s_c_to_stripe(k).v;
1177                 unsigned i;
1178
1179                 if (old->nr_blocks != new->v.nr_blocks) {
1180                         bch_err(c, "error updating stripe: nr_blocks does not match");
1181                         ret = -EINVAL;
1182                         goto err;
1183                 }
1184
1185                 for (i = 0; i < new->v.nr_blocks; i++) {
1186                         unsigned v = stripe_blockcount_get(old, i);
1187
1188                         BUG_ON(v &&
1189                                (old->ptrs[i].dev != new->v.ptrs[i].dev ||
1190                                 old->ptrs[i].gen != new->v.ptrs[i].gen ||
1191                                 old->ptrs[i].offset != new->v.ptrs[i].offset));
1192
1193                         stripe_blockcount_set(&new->v, i, v);
1194                 }
1195         }
1196
1197         ret = bch2_trans_update(trans, &iter, &new->k_i, 0);
1198 err:
1199         bch2_trans_iter_exit(trans, &iter);
1200         return ret;
1201 }
1202
1203 static int ec_stripe_update_extent(struct btree_trans *trans,
1204                                    struct bch_dev *ca,
1205                                    struct bpos bucket, u8 gen,
1206                                    struct ec_stripe_buf *s,
1207                                    struct bpos *bp_pos)
1208 {
1209         struct bch_stripe *v = &bkey_i_to_stripe(&s->key)->v;
1210         struct bch_fs *c = trans->c;
1211         struct bch_backpointer bp;
1212         struct btree_iter iter;
1213         struct bkey_s_c k;
1214         const struct bch_extent_ptr *ptr_c;
1215         struct bch_extent_ptr *ec_ptr = NULL;
1216         struct bch_extent_stripe_ptr stripe_ptr;
1217         struct bkey_i *n;
1218         int ret, dev, block;
1219
1220         ret = bch2_get_next_backpointer(trans, ca, bucket, gen,
1221                                 bp_pos, &bp, BTREE_ITER_cached);
1222         if (ret)
1223                 return ret;
1224         if (bpos_eq(*bp_pos, SPOS_MAX))
1225                 return 0;
1226
1227         if (bp.level) {
1228                 struct printbuf buf = PRINTBUF;
1229                 struct btree_iter node_iter;
1230                 struct btree *b;
1231
1232                 b = bch2_backpointer_get_node(trans, &node_iter, *bp_pos, bp);
1233                 bch2_trans_iter_exit(trans, &node_iter);
1234
1235                 if (!b)
1236                         return 0;
1237
1238                 prt_printf(&buf, "found btree node in erasure coded bucket: b=%px\n", b);
1239                 bch2_backpointer_to_text(&buf, &bp);
1240
1241                 bch2_fs_inconsistent(c, "%s", buf.buf);
1242                 printbuf_exit(&buf);
1243                 return -EIO;
1244         }
1245
1246         k = bch2_backpointer_get_key(trans, &iter, *bp_pos, bp, BTREE_ITER_intent);
1247         ret = bkey_err(k);
1248         if (ret)
1249                 return ret;
1250         if (!k.k) {
1251                 /*
1252                  * extent no longer exists - we could flush the btree
1253                  * write buffer and retry to verify, but no need:
1254                  */
1255                 return 0;
1256         }
1257
1258         if (extent_has_stripe_ptr(k, s->key.k.p.offset))
1259                 goto out;
1260
1261         ptr_c = bkey_matches_stripe(v, k, &block);
1262         /*
1263          * It doesn't generally make sense to erasure code cached ptrs:
1264          * XXX: should we be incrementing a counter?
1265          */
1266         if (!ptr_c || ptr_c->cached)
1267                 goto out;
1268
1269         dev = v->ptrs[block].dev;
1270
1271         n = bch2_trans_kmalloc(trans, bkey_bytes(k.k) + sizeof(stripe_ptr));
1272         ret = PTR_ERR_OR_ZERO(n);
1273         if (ret)
1274                 goto out;
1275
1276         bkey_reassemble(n, k);
1277
1278         bch2_bkey_drop_ptrs(bkey_i_to_s(n), ptr, ptr->dev != dev);
1279         ec_ptr = bch2_bkey_has_device(bkey_i_to_s(n), dev);
1280         BUG_ON(!ec_ptr);
1281
1282         stripe_ptr = (struct bch_extent_stripe_ptr) {
1283                 .type = 1 << BCH_EXTENT_ENTRY_stripe_ptr,
1284                 .block          = block,
1285                 .redundancy     = v->nr_redundant,
1286                 .idx            = s->key.k.p.offset,
1287         };
1288
1289         __extent_entry_insert(n,
1290                         (union bch_extent_entry *) ec_ptr,
1291                         (union bch_extent_entry *) &stripe_ptr);
1292
1293         ret = bch2_trans_update(trans, &iter, n, 0);
1294 out:
1295         bch2_trans_iter_exit(trans, &iter);
1296         return ret;
1297 }
1298
1299 static int ec_stripe_update_bucket(struct btree_trans *trans, struct ec_stripe_buf *s,
1300                                    unsigned block)
1301 {
1302         struct bch_fs *c = trans->c;
1303         struct bch_stripe *v = &bkey_i_to_stripe(&s->key)->v;
1304         struct bch_extent_ptr ptr = v->ptrs[block];
1305         struct bpos bp_pos = POS_MIN;
1306         int ret = 0;
1307
1308         struct bch_dev *ca = bch2_dev_tryget(c, ptr.dev);
1309         if (!ca)
1310                 return -EIO;
1311
1312         struct bpos bucket_pos = PTR_BUCKET_POS(ca, &ptr);
1313
1314         while (1) {
1315                 ret = commit_do(trans, NULL, NULL,
1316                                 BCH_TRANS_COMMIT_no_check_rw|
1317                                 BCH_TRANS_COMMIT_no_enospc,
1318                         ec_stripe_update_extent(trans, ca, bucket_pos, ptr.gen, s, &bp_pos));
1319                 if (ret)
1320                         break;
1321                 if (bkey_eq(bp_pos, POS_MAX))
1322                         break;
1323
1324                 bp_pos = bpos_nosnap_successor(bp_pos);
1325         }
1326
1327         bch2_dev_put(ca);
1328         return ret;
1329 }
1330
1331 static int ec_stripe_update_extents(struct bch_fs *c, struct ec_stripe_buf *s)
1332 {
1333         struct btree_trans *trans = bch2_trans_get(c);
1334         struct bch_stripe *v = &bkey_i_to_stripe(&s->key)->v;
1335         unsigned i, nr_data = v->nr_blocks - v->nr_redundant;
1336         int ret = 0;
1337
1338         ret = bch2_btree_write_buffer_flush_sync(trans);
1339         if (ret)
1340                 goto err;
1341
1342         for (i = 0; i < nr_data; i++) {
1343                 ret = ec_stripe_update_bucket(trans, s, i);
1344                 if (ret)
1345                         break;
1346         }
1347 err:
1348         bch2_trans_put(trans);
1349
1350         return ret;
1351 }
1352
1353 static void zero_out_rest_of_ec_bucket(struct bch_fs *c,
1354                                        struct ec_stripe_new *s,
1355                                        unsigned block,
1356                                        struct open_bucket *ob)
1357 {
1358         struct bch_dev *ca = bch2_dev_get_ioref(c, ob->dev, WRITE);
1359         if (!ca) {
1360                 s->err = -BCH_ERR_erofs_no_writes;
1361                 return;
1362         }
1363
1364         unsigned offset = ca->mi.bucket_size - ob->sectors_free;
1365         memset(s->new_stripe.data[block] + (offset << 9),
1366                0,
1367                ob->sectors_free << 9);
1368
1369         int ret = blkdev_issue_zeroout(ca->disk_sb.bdev,
1370                         ob->bucket * ca->mi.bucket_size + offset,
1371                         ob->sectors_free,
1372                         GFP_KERNEL, 0);
1373
1374         percpu_ref_put(&ca->io_ref);
1375
1376         if (ret)
1377                 s->err = ret;
1378 }
1379
1380 void bch2_ec_stripe_new_free(struct bch_fs *c, struct ec_stripe_new *s)
1381 {
1382         if (s->idx)
1383                 bch2_stripe_close(c, s);
1384         kfree(s);
1385 }
1386
1387 /*
1388  * data buckets of new stripe all written: create the stripe
1389  */
1390 static void ec_stripe_create(struct ec_stripe_new *s)
1391 {
1392         struct bch_fs *c = s->c;
1393         struct open_bucket *ob;
1394         struct bch_stripe *v = &bkey_i_to_stripe(&s->new_stripe.key)->v;
1395         unsigned i, nr_data = v->nr_blocks - v->nr_redundant;
1396         int ret;
1397
1398         BUG_ON(s->h->s == s);
1399
1400         closure_sync(&s->iodone);
1401
1402         if (!s->err) {
1403                 for (i = 0; i < nr_data; i++)
1404                         if (s->blocks[i]) {
1405                                 ob = c->open_buckets + s->blocks[i];
1406
1407                                 if (ob->sectors_free)
1408                                         zero_out_rest_of_ec_bucket(c, s, i, ob);
1409                         }
1410         }
1411
1412         if (s->err) {
1413                 if (!bch2_err_matches(s->err, EROFS))
1414                         bch_err(c, "error creating stripe: error writing data buckets");
1415                 goto err;
1416         }
1417
1418         if (s->have_existing_stripe) {
1419                 ec_validate_checksums(c, &s->existing_stripe);
1420
1421                 if (ec_do_recov(c, &s->existing_stripe)) {
1422                         bch_err(c, "error creating stripe: error reading existing stripe");
1423                         goto err;
1424                 }
1425
1426                 for (i = 0; i < nr_data; i++)
1427                         if (stripe_blockcount_get(&bkey_i_to_stripe(&s->existing_stripe.key)->v, i))
1428                                 swap(s->new_stripe.data[i],
1429                                      s->existing_stripe.data[i]);
1430
1431                 ec_stripe_buf_exit(&s->existing_stripe);
1432         }
1433
1434         BUG_ON(!s->allocated);
1435         BUG_ON(!s->idx);
1436
1437         ec_generate_ec(&s->new_stripe);
1438
1439         ec_generate_checksums(&s->new_stripe);
1440
1441         /* write p/q: */
1442         for (i = nr_data; i < v->nr_blocks; i++)
1443                 ec_block_io(c, &s->new_stripe, REQ_OP_WRITE, i, &s->iodone);
1444         closure_sync(&s->iodone);
1445
1446         if (ec_nr_failed(&s->new_stripe)) {
1447                 bch_err(c, "error creating stripe: error writing redundancy buckets");
1448                 goto err;
1449         }
1450
1451         ret = bch2_trans_do(c, &s->res, NULL,
1452                             BCH_TRANS_COMMIT_no_check_rw|
1453                             BCH_TRANS_COMMIT_no_enospc,
1454                             ec_stripe_key_update(trans,
1455                                         bkey_i_to_stripe(&s->new_stripe.key),
1456                                         !s->have_existing_stripe));
1457         bch_err_msg(c, ret, "creating stripe key");
1458         if (ret) {
1459                 goto err;
1460         }
1461
1462         ret = ec_stripe_update_extents(c, &s->new_stripe);
1463         bch_err_msg(c, ret, "error updating extents");
1464         if (ret)
1465                 goto err;
1466 err:
1467         bch2_disk_reservation_put(c, &s->res);
1468
1469         for (i = 0; i < v->nr_blocks; i++)
1470                 if (s->blocks[i]) {
1471                         ob = c->open_buckets + s->blocks[i];
1472
1473                         if (i < nr_data) {
1474                                 ob->ec = NULL;
1475                                 __bch2_open_bucket_put(c, ob);
1476                         } else {
1477                                 bch2_open_bucket_put(c, ob);
1478                         }
1479                 }
1480
1481         mutex_lock(&c->ec_stripe_new_lock);
1482         list_del(&s->list);
1483         mutex_unlock(&c->ec_stripe_new_lock);
1484         wake_up(&c->ec_stripe_new_wait);
1485
1486         ec_stripe_buf_exit(&s->existing_stripe);
1487         ec_stripe_buf_exit(&s->new_stripe);
1488         closure_debug_destroy(&s->iodone);
1489
1490         ec_stripe_new_put(c, s, STRIPE_REF_stripe);
1491 }
1492
1493 static struct ec_stripe_new *get_pending_stripe(struct bch_fs *c)
1494 {
1495         struct ec_stripe_new *s;
1496
1497         mutex_lock(&c->ec_stripe_new_lock);
1498         list_for_each_entry(s, &c->ec_stripe_new_list, list)
1499                 if (!atomic_read(&s->ref[STRIPE_REF_io]))
1500                         goto out;
1501         s = NULL;
1502 out:
1503         mutex_unlock(&c->ec_stripe_new_lock);
1504
1505         return s;
1506 }
1507
1508 static void ec_stripe_create_work(struct work_struct *work)
1509 {
1510         struct bch_fs *c = container_of(work,
1511                 struct bch_fs, ec_stripe_create_work);
1512         struct ec_stripe_new *s;
1513
1514         while ((s = get_pending_stripe(c)))
1515                 ec_stripe_create(s);
1516
1517         bch2_write_ref_put(c, BCH_WRITE_REF_stripe_create);
1518 }
1519
1520 void bch2_ec_do_stripe_creates(struct bch_fs *c)
1521 {
1522         bch2_write_ref_get(c, BCH_WRITE_REF_stripe_create);
1523
1524         if (!queue_work(system_long_wq, &c->ec_stripe_create_work))
1525                 bch2_write_ref_put(c, BCH_WRITE_REF_stripe_create);
1526 }
1527
1528 static void ec_stripe_set_pending(struct bch_fs *c, struct ec_stripe_head *h)
1529 {
1530         struct ec_stripe_new *s = h->s;
1531
1532         BUG_ON(!s->allocated && !s->err);
1533
1534         h->s            = NULL;
1535         s->pending      = true;
1536
1537         mutex_lock(&c->ec_stripe_new_lock);
1538         list_add(&s->list, &c->ec_stripe_new_list);
1539         mutex_unlock(&c->ec_stripe_new_lock);
1540
1541         ec_stripe_new_put(c, s, STRIPE_REF_io);
1542 }
1543
1544 void bch2_ec_bucket_cancel(struct bch_fs *c, struct open_bucket *ob)
1545 {
1546         struct ec_stripe_new *s = ob->ec;
1547
1548         s->err = -EIO;
1549 }
1550
1551 void *bch2_writepoint_ec_buf(struct bch_fs *c, struct write_point *wp)
1552 {
1553         struct open_bucket *ob = ec_open_bucket(c, &wp->ptrs);
1554         if (!ob)
1555                 return NULL;
1556
1557         BUG_ON(!ob->ec->new_stripe.data[ob->ec_idx]);
1558
1559         struct bch_dev *ca      = ob_dev(c, ob);
1560         unsigned offset         = ca->mi.bucket_size - ob->sectors_free;
1561
1562         return ob->ec->new_stripe.data[ob->ec_idx] + (offset << 9);
1563 }
1564
1565 static int unsigned_cmp(const void *_l, const void *_r)
1566 {
1567         unsigned l = *((const unsigned *) _l);
1568         unsigned r = *((const unsigned *) _r);
1569
1570         return cmp_int(l, r);
1571 }
1572
1573 /* pick most common bucket size: */
1574 static unsigned pick_blocksize(struct bch_fs *c,
1575                                struct bch_devs_mask *devs)
1576 {
1577         unsigned nr = 0, sizes[BCH_SB_MEMBERS_MAX];
1578         struct {
1579                 unsigned nr, size;
1580         } cur = { 0, 0 }, best = { 0, 0 };
1581
1582         for_each_member_device_rcu(c, ca, devs)
1583                 sizes[nr++] = ca->mi.bucket_size;
1584
1585         sort(sizes, nr, sizeof(unsigned), unsigned_cmp, NULL);
1586
1587         for (unsigned i = 0; i < nr; i++) {
1588                 if (sizes[i] != cur.size) {
1589                         if (cur.nr > best.nr)
1590                                 best = cur;
1591
1592                         cur.nr = 0;
1593                         cur.size = sizes[i];
1594                 }
1595
1596                 cur.nr++;
1597         }
1598
1599         if (cur.nr > best.nr)
1600                 best = cur;
1601
1602         return best.size;
1603 }
1604
1605 static bool may_create_new_stripe(struct bch_fs *c)
1606 {
1607         return false;
1608 }
1609
1610 static void ec_stripe_key_init(struct bch_fs *c,
1611                                struct bkey_i *k,
1612                                unsigned nr_data,
1613                                unsigned nr_parity,
1614                                unsigned stripe_size)
1615 {
1616         struct bkey_i_stripe *s = bkey_stripe_init(k);
1617         unsigned u64s;
1618
1619         s->v.sectors                    = cpu_to_le16(stripe_size);
1620         s->v.algorithm                  = 0;
1621         s->v.nr_blocks                  = nr_data + nr_parity;
1622         s->v.nr_redundant               = nr_parity;
1623         s->v.csum_granularity_bits      = ilog2(c->opts.encoded_extent_max >> 9);
1624         s->v.csum_type                  = BCH_CSUM_crc32c;
1625         s->v.pad                        = 0;
1626
1627         while ((u64s = stripe_val_u64s(&s->v)) > BKEY_VAL_U64s_MAX) {
1628                 BUG_ON(1 << s->v.csum_granularity_bits >=
1629                        le16_to_cpu(s->v.sectors) ||
1630                        s->v.csum_granularity_bits == U8_MAX);
1631                 s->v.csum_granularity_bits++;
1632         }
1633
1634         set_bkey_val_u64s(&s->k, u64s);
1635 }
1636
1637 static int ec_new_stripe_alloc(struct bch_fs *c, struct ec_stripe_head *h)
1638 {
1639         struct ec_stripe_new *s;
1640
1641         lockdep_assert_held(&h->lock);
1642
1643         s = kzalloc(sizeof(*s), GFP_KERNEL);
1644         if (!s)
1645                 return -BCH_ERR_ENOMEM_ec_new_stripe_alloc;
1646
1647         mutex_init(&s->lock);
1648         closure_init(&s->iodone, NULL);
1649         atomic_set(&s->ref[STRIPE_REF_stripe], 1);
1650         atomic_set(&s->ref[STRIPE_REF_io], 1);
1651         s->c            = c;
1652         s->h            = h;
1653         s->nr_data      = min_t(unsigned, h->nr_active_devs,
1654                                 BCH_BKEY_PTRS_MAX) - h->redundancy;
1655         s->nr_parity    = h->redundancy;
1656
1657         ec_stripe_key_init(c, &s->new_stripe.key,
1658                            s->nr_data, s->nr_parity, h->blocksize);
1659
1660         h->s = s;
1661         return 0;
1662 }
1663
1664 static struct ec_stripe_head *
1665 ec_new_stripe_head_alloc(struct bch_fs *c, unsigned target,
1666                          unsigned algo, unsigned redundancy,
1667                          enum bch_watermark watermark)
1668 {
1669         struct ec_stripe_head *h;
1670
1671         h = kzalloc(sizeof(*h), GFP_KERNEL);
1672         if (!h)
1673                 return NULL;
1674
1675         mutex_init(&h->lock);
1676         BUG_ON(!mutex_trylock(&h->lock));
1677
1678         h->target       = target;
1679         h->algo         = algo;
1680         h->redundancy   = redundancy;
1681         h->watermark    = watermark;
1682
1683         rcu_read_lock();
1684         h->devs = target_rw_devs(c, BCH_DATA_user, target);
1685
1686         for_each_member_device_rcu(c, ca, &h->devs)
1687                 if (!ca->mi.durability)
1688                         __clear_bit(ca->dev_idx, h->devs.d);
1689
1690         h->blocksize = pick_blocksize(c, &h->devs);
1691
1692         for_each_member_device_rcu(c, ca, &h->devs)
1693                 if (ca->mi.bucket_size == h->blocksize)
1694                         h->nr_active_devs++;
1695
1696         rcu_read_unlock();
1697
1698         /*
1699          * If we only have redundancy + 1 devices, we're better off with just
1700          * replication:
1701          */
1702         if (h->nr_active_devs < h->redundancy + 2)
1703                 bch_err(c, "insufficient devices available to create stripe (have %u, need %u) - mismatched bucket sizes?",
1704                         h->nr_active_devs, h->redundancy + 2);
1705
1706         list_add(&h->list, &c->ec_stripe_head_list);
1707         return h;
1708 }
1709
1710 void bch2_ec_stripe_head_put(struct bch_fs *c, struct ec_stripe_head *h)
1711 {
1712         if (h->s &&
1713             h->s->allocated &&
1714             bitmap_weight(h->s->blocks_allocated,
1715                           h->s->nr_data) == h->s->nr_data)
1716                 ec_stripe_set_pending(c, h);
1717
1718         mutex_unlock(&h->lock);
1719 }
1720
1721 static struct ec_stripe_head *
1722 __bch2_ec_stripe_head_get(struct btree_trans *trans,
1723                           unsigned target,
1724                           unsigned algo,
1725                           unsigned redundancy,
1726                           enum bch_watermark watermark)
1727 {
1728         struct bch_fs *c = trans->c;
1729         struct ec_stripe_head *h;
1730         int ret;
1731
1732         if (!redundancy)
1733                 return NULL;
1734
1735         ret = bch2_trans_mutex_lock(trans, &c->ec_stripe_head_lock);
1736         if (ret)
1737                 return ERR_PTR(ret);
1738
1739         if (test_bit(BCH_FS_going_ro, &c->flags)) {
1740                 h = ERR_PTR(-BCH_ERR_erofs_no_writes);
1741                 goto found;
1742         }
1743
1744         list_for_each_entry(h, &c->ec_stripe_head_list, list)
1745                 if (h->target           == target &&
1746                     h->algo             == algo &&
1747                     h->redundancy       == redundancy &&
1748                     h->watermark        == watermark) {
1749                         ret = bch2_trans_mutex_lock(trans, &h->lock);
1750                         if (ret)
1751                                 h = ERR_PTR(ret);
1752                         goto found;
1753                 }
1754
1755         h = ec_new_stripe_head_alloc(c, target, algo, redundancy, watermark);
1756 found:
1757         if (!IS_ERR_OR_NULL(h) &&
1758             h->nr_active_devs < h->redundancy + 2) {
1759                 mutex_unlock(&h->lock);
1760                 h = NULL;
1761         }
1762         mutex_unlock(&c->ec_stripe_head_lock);
1763         return h;
1764 }
1765
1766 static int new_stripe_alloc_buckets(struct btree_trans *trans, struct ec_stripe_head *h,
1767                                     enum bch_watermark watermark, struct closure *cl)
1768 {
1769         struct bch_fs *c = trans->c;
1770         struct bch_devs_mask devs = h->devs;
1771         struct open_bucket *ob;
1772         struct open_buckets buckets;
1773         struct bch_stripe *v = &bkey_i_to_stripe(&h->s->new_stripe.key)->v;
1774         unsigned i, j, nr_have_parity = 0, nr_have_data = 0;
1775         bool have_cache = true;
1776         int ret = 0;
1777
1778         BUG_ON(v->nr_blocks     != h->s->nr_data + h->s->nr_parity);
1779         BUG_ON(v->nr_redundant  != h->s->nr_parity);
1780
1781         for_each_set_bit(i, h->s->blocks_gotten, v->nr_blocks) {
1782                 __clear_bit(v->ptrs[i].dev, devs.d);
1783                 if (i < h->s->nr_data)
1784                         nr_have_data++;
1785                 else
1786                         nr_have_parity++;
1787         }
1788
1789         BUG_ON(nr_have_data     > h->s->nr_data);
1790         BUG_ON(nr_have_parity   > h->s->nr_parity);
1791
1792         buckets.nr = 0;
1793         if (nr_have_parity < h->s->nr_parity) {
1794                 ret = bch2_bucket_alloc_set_trans(trans, &buckets,
1795                                             &h->parity_stripe,
1796                                             &devs,
1797                                             h->s->nr_parity,
1798                                             &nr_have_parity,
1799                                             &have_cache, 0,
1800                                             BCH_DATA_parity,
1801                                             watermark,
1802                                             cl);
1803
1804                 open_bucket_for_each(c, &buckets, ob, i) {
1805                         j = find_next_zero_bit(h->s->blocks_gotten,
1806                                                h->s->nr_data + h->s->nr_parity,
1807                                                h->s->nr_data);
1808                         BUG_ON(j >= h->s->nr_data + h->s->nr_parity);
1809
1810                         h->s->blocks[j] = buckets.v[i];
1811                         v->ptrs[j] = bch2_ob_ptr(c, ob);
1812                         __set_bit(j, h->s->blocks_gotten);
1813                 }
1814
1815                 if (ret)
1816                         return ret;
1817         }
1818
1819         buckets.nr = 0;
1820         if (nr_have_data < h->s->nr_data) {
1821                 ret = bch2_bucket_alloc_set_trans(trans, &buckets,
1822                                             &h->block_stripe,
1823                                             &devs,
1824                                             h->s->nr_data,
1825                                             &nr_have_data,
1826                                             &have_cache, 0,
1827                                             BCH_DATA_user,
1828                                             watermark,
1829                                             cl);
1830
1831                 open_bucket_for_each(c, &buckets, ob, i) {
1832                         j = find_next_zero_bit(h->s->blocks_gotten,
1833                                                h->s->nr_data, 0);
1834                         BUG_ON(j >= h->s->nr_data);
1835
1836                         h->s->blocks[j] = buckets.v[i];
1837                         v->ptrs[j] = bch2_ob_ptr(c, ob);
1838                         __set_bit(j, h->s->blocks_gotten);
1839                 }
1840
1841                 if (ret)
1842                         return ret;
1843         }
1844
1845         return 0;
1846 }
1847
1848 /* XXX: doesn't obey target: */
1849 static s64 get_existing_stripe(struct bch_fs *c,
1850                                struct ec_stripe_head *head)
1851 {
1852         ec_stripes_heap *h = &c->ec_stripes_heap;
1853         struct stripe *m;
1854         size_t heap_idx;
1855         u64 stripe_idx;
1856         s64 ret = -1;
1857
1858         if (may_create_new_stripe(c))
1859                 return -1;
1860
1861         mutex_lock(&c->ec_stripes_heap_lock);
1862         for (heap_idx = 0; heap_idx < h->used; heap_idx++) {
1863                 /* No blocks worth reusing, stripe will just be deleted: */
1864                 if (!h->data[heap_idx].blocks_nonempty)
1865                         continue;
1866
1867                 stripe_idx = h->data[heap_idx].idx;
1868
1869                 m = genradix_ptr(&c->stripes, stripe_idx);
1870
1871                 if (m->algorithm        == head->algo &&
1872                     m->nr_redundant     == head->redundancy &&
1873                     m->sectors          == head->blocksize &&
1874                     m->blocks_nonempty  < m->nr_blocks - m->nr_redundant &&
1875                     bch2_try_open_stripe(c, head->s, stripe_idx)) {
1876                         ret = stripe_idx;
1877                         break;
1878                 }
1879         }
1880         mutex_unlock(&c->ec_stripes_heap_lock);
1881         return ret;
1882 }
1883
1884 static int __bch2_ec_stripe_head_reuse(struct btree_trans *trans, struct ec_stripe_head *h)
1885 {
1886         struct bch_fs *c = trans->c;
1887         struct bch_stripe *new_v = &bkey_i_to_stripe(&h->s->new_stripe.key)->v;
1888         struct bch_stripe *existing_v;
1889         unsigned i;
1890         s64 idx;
1891         int ret;
1892
1893         /*
1894          * If we can't allocate a new stripe, and there's no stripes with empty
1895          * blocks for us to reuse, that means we have to wait on copygc:
1896          */
1897         idx = get_existing_stripe(c, h);
1898         if (idx < 0)
1899                 return -BCH_ERR_stripe_alloc_blocked;
1900
1901         ret = get_stripe_key_trans(trans, idx, &h->s->existing_stripe);
1902         bch2_fs_fatal_err_on(ret && !bch2_err_matches(ret, BCH_ERR_transaction_restart), c,
1903                              "reading stripe key: %s", bch2_err_str(ret));
1904         if (ret) {
1905                 bch2_stripe_close(c, h->s);
1906                 return ret;
1907         }
1908
1909         existing_v = &bkey_i_to_stripe(&h->s->existing_stripe.key)->v;
1910
1911         BUG_ON(existing_v->nr_redundant != h->s->nr_parity);
1912         h->s->nr_data = existing_v->nr_blocks -
1913                 existing_v->nr_redundant;
1914
1915         ret = ec_stripe_buf_init(&h->s->existing_stripe, 0, h->blocksize);
1916         if (ret) {
1917                 bch2_stripe_close(c, h->s);
1918                 return ret;
1919         }
1920
1921         BUG_ON(h->s->existing_stripe.size != h->blocksize);
1922         BUG_ON(h->s->existing_stripe.size != le16_to_cpu(existing_v->sectors));
1923
1924         /*
1925          * Free buckets we initially allocated - they might conflict with
1926          * blocks from the stripe we're reusing:
1927          */
1928         for_each_set_bit(i, h->s->blocks_gotten, new_v->nr_blocks) {
1929                 bch2_open_bucket_put(c, c->open_buckets + h->s->blocks[i]);
1930                 h->s->blocks[i] = 0;
1931         }
1932         memset(h->s->blocks_gotten, 0, sizeof(h->s->blocks_gotten));
1933         memset(h->s->blocks_allocated, 0, sizeof(h->s->blocks_allocated));
1934
1935         for (i = 0; i < existing_v->nr_blocks; i++) {
1936                 if (stripe_blockcount_get(existing_v, i)) {
1937                         __set_bit(i, h->s->blocks_gotten);
1938                         __set_bit(i, h->s->blocks_allocated);
1939                 }
1940
1941                 ec_block_io(c, &h->s->existing_stripe, READ, i, &h->s->iodone);
1942         }
1943
1944         bkey_copy(&h->s->new_stripe.key, &h->s->existing_stripe.key);
1945         h->s->have_existing_stripe = true;
1946
1947         return 0;
1948 }
1949
1950 static int __bch2_ec_stripe_head_reserve(struct btree_trans *trans, struct ec_stripe_head *h)
1951 {
1952         struct bch_fs *c = trans->c;
1953         struct btree_iter iter;
1954         struct bkey_s_c k;
1955         struct bpos min_pos = POS(0, 1);
1956         struct bpos start_pos = bpos_max(min_pos, POS(0, c->ec_stripe_hint));
1957         int ret;
1958
1959         if (!h->s->res.sectors) {
1960                 ret = bch2_disk_reservation_get(c, &h->s->res,
1961                                         h->blocksize,
1962                                         h->s->nr_parity,
1963                                         BCH_DISK_RESERVATION_NOFAIL);
1964                 if (ret)
1965                         return ret;
1966         }
1967
1968         for_each_btree_key_norestart(trans, iter, BTREE_ID_stripes, start_pos,
1969                            BTREE_ITER_slots|BTREE_ITER_intent, k, ret) {
1970                 if (bkey_gt(k.k->p, POS(0, U32_MAX))) {
1971                         if (start_pos.offset) {
1972                                 start_pos = min_pos;
1973                                 bch2_btree_iter_set_pos(&iter, start_pos);
1974                                 continue;
1975                         }
1976
1977                         ret = -BCH_ERR_ENOSPC_stripe_create;
1978                         break;
1979                 }
1980
1981                 if (bkey_deleted(k.k) &&
1982                     bch2_try_open_stripe(c, h->s, k.k->p.offset))
1983                         break;
1984         }
1985
1986         c->ec_stripe_hint = iter.pos.offset;
1987
1988         if (ret)
1989                 goto err;
1990
1991         ret = ec_stripe_mem_alloc(trans, &iter);
1992         if (ret) {
1993                 bch2_stripe_close(c, h->s);
1994                 goto err;
1995         }
1996
1997         h->s->new_stripe.key.k.p = iter.pos;
1998 out:
1999         bch2_trans_iter_exit(trans, &iter);
2000         return ret;
2001 err:
2002         bch2_disk_reservation_put(c, &h->s->res);
2003         goto out;
2004 }
2005
2006 struct ec_stripe_head *bch2_ec_stripe_head_get(struct btree_trans *trans,
2007                                                unsigned target,
2008                                                unsigned algo,
2009                                                unsigned redundancy,
2010                                                enum bch_watermark watermark,
2011                                                struct closure *cl)
2012 {
2013         struct bch_fs *c = trans->c;
2014         struct ec_stripe_head *h;
2015         bool waiting = false;
2016         int ret;
2017
2018         h = __bch2_ec_stripe_head_get(trans, target, algo, redundancy, watermark);
2019         if (IS_ERR_OR_NULL(h))
2020                 return h;
2021
2022         if (!h->s) {
2023                 ret = ec_new_stripe_alloc(c, h);
2024                 if (ret) {
2025                         bch_err(c, "failed to allocate new stripe");
2026                         goto err;
2027                 }
2028         }
2029
2030         if (h->s->allocated)
2031                 goto allocated;
2032
2033         if (h->s->have_existing_stripe)
2034                 goto alloc_existing;
2035
2036         /* First, try to allocate a full stripe: */
2037         ret =   new_stripe_alloc_buckets(trans, h, BCH_WATERMARK_stripe, NULL) ?:
2038                 __bch2_ec_stripe_head_reserve(trans, h);
2039         if (!ret)
2040                 goto allocate_buf;
2041         if (bch2_err_matches(ret, BCH_ERR_transaction_restart) ||
2042             bch2_err_matches(ret, ENOMEM))
2043                 goto err;
2044
2045         /*
2046          * Not enough buckets available for a full stripe: we must reuse an
2047          * existing stripe:
2048          */
2049         while (1) {
2050                 ret = __bch2_ec_stripe_head_reuse(trans, h);
2051                 if (!ret)
2052                         break;
2053                 if (waiting || !cl || ret != -BCH_ERR_stripe_alloc_blocked)
2054                         goto err;
2055
2056                 if (watermark == BCH_WATERMARK_copygc) {
2057                         ret =   new_stripe_alloc_buckets(trans, h, watermark, NULL) ?:
2058                                 __bch2_ec_stripe_head_reserve(trans, h);
2059                         if (ret)
2060                                 goto err;
2061                         goto allocate_buf;
2062                 }
2063
2064                 /* XXX freelist_wait? */
2065                 closure_wait(&c->freelist_wait, cl);
2066                 waiting = true;
2067         }
2068
2069         if (waiting)
2070                 closure_wake_up(&c->freelist_wait);
2071 alloc_existing:
2072         /*
2073          * Retry allocating buckets, with the watermark for this
2074          * particular write:
2075          */
2076         ret = new_stripe_alloc_buckets(trans, h, watermark, cl);
2077         if (ret)
2078                 goto err;
2079
2080 allocate_buf:
2081         ret = ec_stripe_buf_init(&h->s->new_stripe, 0, h->blocksize);
2082         if (ret)
2083                 goto err;
2084
2085         h->s->allocated = true;
2086 allocated:
2087         BUG_ON(!h->s->idx);
2088         BUG_ON(!h->s->new_stripe.data[0]);
2089         BUG_ON(trans->restarted);
2090         return h;
2091 err:
2092         bch2_ec_stripe_head_put(c, h);
2093         return ERR_PTR(ret);
2094 }
2095
2096 static void __bch2_ec_stop(struct bch_fs *c, struct bch_dev *ca)
2097 {
2098         struct ec_stripe_head *h;
2099         struct open_bucket *ob;
2100         unsigned i;
2101
2102         mutex_lock(&c->ec_stripe_head_lock);
2103         list_for_each_entry(h, &c->ec_stripe_head_list, list) {
2104                 mutex_lock(&h->lock);
2105                 if (!h->s)
2106                         goto unlock;
2107
2108                 if (!ca)
2109                         goto found;
2110
2111                 for (i = 0; i < bkey_i_to_stripe(&h->s->new_stripe.key)->v.nr_blocks; i++) {
2112                         if (!h->s->blocks[i])
2113                                 continue;
2114
2115                         ob = c->open_buckets + h->s->blocks[i];
2116                         if (ob->dev == ca->dev_idx)
2117                                 goto found;
2118                 }
2119                 goto unlock;
2120 found:
2121                 h->s->err = -BCH_ERR_erofs_no_writes;
2122                 ec_stripe_set_pending(c, h);
2123 unlock:
2124                 mutex_unlock(&h->lock);
2125         }
2126         mutex_unlock(&c->ec_stripe_head_lock);
2127 }
2128
2129 void bch2_ec_stop_dev(struct bch_fs *c, struct bch_dev *ca)
2130 {
2131         __bch2_ec_stop(c, ca);
2132 }
2133
2134 void bch2_fs_ec_stop(struct bch_fs *c)
2135 {
2136         __bch2_ec_stop(c, NULL);
2137 }
2138
2139 static bool bch2_fs_ec_flush_done(struct bch_fs *c)
2140 {
2141         bool ret;
2142
2143         mutex_lock(&c->ec_stripe_new_lock);
2144         ret = list_empty(&c->ec_stripe_new_list);
2145         mutex_unlock(&c->ec_stripe_new_lock);
2146
2147         return ret;
2148 }
2149
2150 void bch2_fs_ec_flush(struct bch_fs *c)
2151 {
2152         wait_event(c->ec_stripe_new_wait, bch2_fs_ec_flush_done(c));
2153 }
2154
2155 int bch2_stripes_read(struct bch_fs *c)
2156 {
2157         int ret = bch2_trans_run(c,
2158                 for_each_btree_key(trans, iter, BTREE_ID_stripes, POS_MIN,
2159                                    BTREE_ITER_prefetch, k, ({
2160                         if (k.k->type != KEY_TYPE_stripe)
2161                                 continue;
2162
2163                         ret = __ec_stripe_mem_alloc(c, k.k->p.offset, GFP_KERNEL);
2164                         if (ret)
2165                                 break;
2166
2167                         const struct bch_stripe *s = bkey_s_c_to_stripe(k).v;
2168
2169                         struct stripe *m = genradix_ptr(&c->stripes, k.k->p.offset);
2170                         m->sectors      = le16_to_cpu(s->sectors);
2171                         m->algorithm    = s->algorithm;
2172                         m->nr_blocks    = s->nr_blocks;
2173                         m->nr_redundant = s->nr_redundant;
2174                         m->blocks_nonempty = 0;
2175
2176                         for (unsigned i = 0; i < s->nr_blocks; i++)
2177                                 m->blocks_nonempty += !!stripe_blockcount_get(s, i);
2178
2179                         bch2_stripes_heap_insert(c, m, k.k->p.offset);
2180                         0;
2181                 })));
2182         bch_err_fn(c, ret);
2183         return ret;
2184 }
2185
2186 void bch2_stripes_heap_to_text(struct printbuf *out, struct bch_fs *c)
2187 {
2188         ec_stripes_heap *h = &c->ec_stripes_heap;
2189         struct stripe *m;
2190         size_t i;
2191
2192         mutex_lock(&c->ec_stripes_heap_lock);
2193         for (i = 0; i < min_t(size_t, h->used, 50); i++) {
2194                 m = genradix_ptr(&c->stripes, h->data[i].idx);
2195
2196                 prt_printf(out, "%zu %u/%u+%u", h->data[i].idx,
2197                        h->data[i].blocks_nonempty,
2198                        m->nr_blocks - m->nr_redundant,
2199                        m->nr_redundant);
2200                 if (bch2_stripe_is_open(c, h->data[i].idx))
2201                         prt_str(out, " open");
2202                 prt_newline(out);
2203         }
2204         mutex_unlock(&c->ec_stripes_heap_lock);
2205 }
2206
2207 void bch2_new_stripes_to_text(struct printbuf *out, struct bch_fs *c)
2208 {
2209         struct ec_stripe_head *h;
2210         struct ec_stripe_new *s;
2211
2212         mutex_lock(&c->ec_stripe_head_lock);
2213         list_for_each_entry(h, &c->ec_stripe_head_list, list) {
2214                 prt_printf(out, "target %u algo %u redundancy %u %s:\n",
2215                        h->target, h->algo, h->redundancy,
2216                        bch2_watermarks[h->watermark]);
2217
2218                 if (h->s)
2219                         prt_printf(out, "\tidx %llu blocks %u+%u allocated %u\n",
2220                                h->s->idx, h->s->nr_data, h->s->nr_parity,
2221                                bitmap_weight(h->s->blocks_allocated,
2222                                              h->s->nr_data));
2223         }
2224         mutex_unlock(&c->ec_stripe_head_lock);
2225
2226         prt_printf(out, "in flight:\n");
2227
2228         mutex_lock(&c->ec_stripe_new_lock);
2229         list_for_each_entry(s, &c->ec_stripe_new_list, list) {
2230                 prt_printf(out, "\tidx %llu blocks %u+%u ref %u %u %s\n",
2231                            s->idx, s->nr_data, s->nr_parity,
2232                            atomic_read(&s->ref[STRIPE_REF_io]),
2233                            atomic_read(&s->ref[STRIPE_REF_stripe]),
2234                            bch2_watermarks[s->h->watermark]);
2235         }
2236         mutex_unlock(&c->ec_stripe_new_lock);
2237 }
2238
2239 void bch2_fs_ec_exit(struct bch_fs *c)
2240 {
2241         struct ec_stripe_head *h;
2242         unsigned i;
2243
2244         while (1) {
2245                 mutex_lock(&c->ec_stripe_head_lock);
2246                 h = list_first_entry_or_null(&c->ec_stripe_head_list,
2247                                              struct ec_stripe_head, list);
2248                 if (h)
2249                         list_del(&h->list);
2250                 mutex_unlock(&c->ec_stripe_head_lock);
2251                 if (!h)
2252                         break;
2253
2254                 if (h->s) {
2255                         for (i = 0; i < bkey_i_to_stripe(&h->s->new_stripe.key)->v.nr_blocks; i++)
2256                                 BUG_ON(h->s->blocks[i]);
2257
2258                         kfree(h->s);
2259                 }
2260                 kfree(h);
2261         }
2262
2263         BUG_ON(!list_empty(&c->ec_stripe_new_list));
2264
2265         free_heap(&c->ec_stripes_heap);
2266         genradix_free(&c->stripes);
2267         bioset_exit(&c->ec_bioset);
2268 }
2269
2270 void bch2_fs_ec_init_early(struct bch_fs *c)
2271 {
2272         spin_lock_init(&c->ec_stripes_new_lock);
2273         mutex_init(&c->ec_stripes_heap_lock);
2274
2275         INIT_LIST_HEAD(&c->ec_stripe_head_list);
2276         mutex_init(&c->ec_stripe_head_lock);
2277
2278         INIT_LIST_HEAD(&c->ec_stripe_new_list);
2279         mutex_init(&c->ec_stripe_new_lock);
2280         init_waitqueue_head(&c->ec_stripe_new_wait);
2281
2282         INIT_WORK(&c->ec_stripe_create_work, ec_stripe_create_work);
2283         INIT_WORK(&c->ec_stripe_delete_work, ec_stripe_delete_work);
2284 }
2285
2286 int bch2_fs_ec_init(struct bch_fs *c)
2287 {
2288         return bioset_init(&c->ec_bioset, 1, offsetof(struct ec_bio, bio),
2289                            BIOSET_NEED_BVECS);
2290 }