fs/bcachefs/reflink.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include "bcachefs.h"
   3 #include "bkey_buf.h"
   4 #include "btree_update.h"
   5 #include "buckets.h"
   6 #include "error.h"
   7 #include "extents.h"
   8 #include "inode.h"
   9 #include "io_misc.h"
  10 #include "io_write.h"
  11 #include "rebalance.h"
  12 #include "reflink.h"
  13 #include "subvolume.h"
  14 #include "super-io.h"
  15
  16 #include <linux/sched/signal.h>
  17
  18 static inline unsigned bkey_type_to_indirect(const struct bkey *k)
  19 {
  20         switch (k->type) {
  21         case KEY_TYPE_extent:
  22                 return KEY_TYPE_reflink_v;
  23         case KEY_TYPE_inline_data:
  24                 return KEY_TYPE_indirect_inline_data;
  25         default:
  26                 return 0;
  27         }
  28 }
  29
  30 /* reflink pointers */
  31
  32 int bch2_reflink_p_invalid(struct bch_fs *c, struct bkey_s_c k,
  33                            enum bch_validate_flags flags,
  34                            struct printbuf *err)
  35 {
  36         struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
  37         int ret = 0;
  38
  39         bkey_fsck_err_on(le64_to_cpu(p.v->idx) < le32_to_cpu(p.v->front_pad),
  40                          c, err, reflink_p_front_pad_bad,
  41                          "idx < front_pad (%llu < %u)",
  42                          le64_to_cpu(p.v->idx), le32_to_cpu(p.v->front_pad));
  43 fsck_err:
  44         return ret;
  45 }
  46
  47 void bch2_reflink_p_to_text(struct printbuf *out, struct bch_fs *c,
  48                             struct bkey_s_c k)
  49 {
  50         struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
  51
  52         prt_printf(out, "idx %llu front_pad %u back_pad %u",
  53                le64_to_cpu(p.v->idx),
  54                le32_to_cpu(p.v->front_pad),
  55                le32_to_cpu(p.v->back_pad));
  56 }
  57
  58 bool bch2_reflink_p_merge(struct bch_fs *c, struct bkey_s _l, struct bkey_s_c _r)
  59 {
  60         struct bkey_s_reflink_p l = bkey_s_to_reflink_p(_l);
  61         struct bkey_s_c_reflink_p r = bkey_s_c_to_reflink_p(_r);
  62
  63         /*
  64          * Disabled for now, the triggers code needs to be reworked for merging
  65          * of reflink pointers to work:
  66          */
  67         return false;
  68
  69         if (le64_to_cpu(l.v->idx) + l.k->size != le64_to_cpu(r.v->idx))
  70                 return false;
  71
  72         bch2_key_resize(l.k, l.k->size + r.k->size);
  73         return true;
  74 }
  75
  76 static int trans_trigger_reflink_p_segment(struct btree_trans *trans,
  77                         struct bkey_s_c_reflink_p p, u64 *idx,
  78                         enum btree_iter_update_trigger_flags flags)
  79 {
  80         struct bch_fs *c = trans->c;
  81         struct btree_iter iter;
  82         struct bkey_i *k;
  83         __le64 *refcount;
  84         int add = !(flags & BTREE_TRIGGER_overwrite) ? 1 : -1;
  85         struct printbuf buf = PRINTBUF;
  86         int ret;
  87
  88         k = bch2_bkey_get_mut_noupdate(trans, &iter,
  89                         BTREE_ID_reflink, POS(0, *idx),
  90                         BTREE_ITER_with_updates);
  91         ret = PTR_ERR_OR_ZERO(k);
  92         if (ret)
  93                 goto err;
  94
  95         refcount = bkey_refcount(bkey_i_to_s(k));
  96         if (!refcount) {
  97                 bch2_bkey_val_to_text(&buf, c, p.s_c);
  98                 bch2_trans_inconsistent(trans,
  99                         "nonexistent indirect extent at %llu while marking\n  %s",
 100                         *idx, buf.buf);
 101                 ret = -EIO;
 102                 goto err;
 103         }
 104
 105         if (!*refcount && (flags & BTREE_TRIGGER_overwrite)) {
 106                 bch2_bkey_val_to_text(&buf, c, p.s_c);
 107                 bch2_trans_inconsistent(trans,
 108                         "indirect extent refcount underflow at %llu while marking\n  %s",
 109                         *idx, buf.buf);
 110                 ret = -EIO;
 111                 goto err;
 112         }
 113
 114         if (flags & BTREE_TRIGGER_insert) {
 115                 struct bch_reflink_p *v = (struct bch_reflink_p *) p.v;
 116                 u64 pad;
 117
 118                 pad = max_t(s64, le32_to_cpu(v->front_pad),
 119                             le64_to_cpu(v->idx) - bkey_start_offset(&k->k));
 120                 BUG_ON(pad > U32_MAX);
 121                 v->front_pad = cpu_to_le32(pad);
 122
 123                 pad = max_t(s64, le32_to_cpu(v->back_pad),
 124                             k->k.p.offset - p.k->size - le64_to_cpu(v->idx));
 125                 BUG_ON(pad > U32_MAX);
 126                 v->back_pad = cpu_to_le32(pad);
 127         }
 128
 129         le64_add_cpu(refcount, add);
 130
 131         bch2_btree_iter_set_pos_to_extent_start(&iter);
 132         ret = bch2_trans_update(trans, &iter, k, 0);
 133         if (ret)
 134                 goto err;
 135
 136         *idx = k->k.p.offset;
 137 err:
 138         bch2_trans_iter_exit(trans, &iter);
 139         printbuf_exit(&buf);
 140         return ret;
 141 }
 142
 143 static s64 gc_trigger_reflink_p_segment(struct btree_trans *trans,
 144                                 struct bkey_s_c_reflink_p p, u64 *idx,
 145                                 enum btree_iter_update_trigger_flags flags,
 146                                 size_t r_idx)
 147 {
 148         struct bch_fs *c = trans->c;
 149         struct reflink_gc *r;
 150         int add = !(flags & BTREE_TRIGGER_overwrite) ? 1 : -1;
 151         u64 start = le64_to_cpu(p.v->idx);
 152         u64 end = le64_to_cpu(p.v->idx) + p.k->size;
 153         u64 next_idx = end + le32_to_cpu(p.v->back_pad);
 154         s64 ret = 0;
 155         struct printbuf buf = PRINTBUF;
 156
 157         if (r_idx >= c->reflink_gc_nr)
 158                 goto not_found;
 159
 160         r = genradix_ptr(&c->reflink_gc_table, r_idx);
 161         next_idx = min(next_idx, r->offset - r->size);
 162         if (*idx < next_idx)
 163                 goto not_found;
 164
 165         BUG_ON((s64) r->refcount + add < 0);
 166
 167         if (flags & BTREE_TRIGGER_gc)
 168                 r->refcount += add;
 169         *idx = r->offset;
 170         return 0;
 171 not_found:
 172         BUG_ON(!(flags & BTREE_TRIGGER_check_repair));
 173
 174         if (fsck_err(c, reflink_p_to_missing_reflink_v,
 175                      "pointer to missing indirect extent\n"
 176                      "  %s\n"
 177                      "  missing range %llu-%llu",
 178                      (bch2_bkey_val_to_text(&buf, c, p.s_c), buf.buf),
 179                      *idx, next_idx)) {
 180                 struct bkey_i *update = bch2_bkey_make_mut_noupdate(trans, p.s_c);
 181                 ret = PTR_ERR_OR_ZERO(update);
 182                 if (ret)
 183                         goto err;
 184
 185                 if (next_idx <= start) {
 186                         bkey_i_to_reflink_p(update)->v.front_pad = cpu_to_le32(start - next_idx);
 187                 } else if (*idx >= end) {
 188                         bkey_i_to_reflink_p(update)->v.back_pad = cpu_to_le32(*idx - end);
 189                 } else {
 190                         bkey_error_init(update);
 191                         update->k.p             = p.k->p;
 192                         update->k.size          = p.k->size;
 193                         set_bkey_val_u64s(&update->k, 0);
 194                 }
 195
 196                 ret = bch2_btree_insert_trans(trans, BTREE_ID_extents, update, BTREE_TRIGGER_norun);
 197         }
 198
 199         *idx = next_idx;
 200 err:
 201 fsck_err:
 202         printbuf_exit(&buf);
 203         return ret;
 204 }
 205
 206 static int __trigger_reflink_p(struct btree_trans *trans,
 207                 enum btree_id btree_id, unsigned level, struct bkey_s_c k,
 208                 enum btree_iter_update_trigger_flags flags)
 209 {
 210         struct bch_fs *c = trans->c;
 211         struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
 212         int ret = 0;
 213
 214         u64 idx = le64_to_cpu(p.v->idx) - le32_to_cpu(p.v->front_pad);
 215         u64 end = le64_to_cpu(p.v->idx) + p.k->size + le32_to_cpu(p.v->back_pad);
 216
 217         if (flags & BTREE_TRIGGER_transactional) {
 218                 while (idx < end && !ret)
 219                         ret = trans_trigger_reflink_p_segment(trans, p, &idx, flags);
 220         }
 221
 222         if (flags & (BTREE_TRIGGER_check_repair|BTREE_TRIGGER_gc)) {
 223                 size_t l = 0, r = c->reflink_gc_nr;
 224
 225                 while (l < r) {
 226                         size_t m = l + (r - l) / 2;
 227                         struct reflink_gc *ref = genradix_ptr(&c->reflink_gc_table, m);
 228                         if (ref->offset <= idx)
 229                                 l = m + 1;
 230                         else
 231                                 r = m;
 232                 }
 233
 234                 while (idx < end && !ret)
 235                         ret = gc_trigger_reflink_p_segment(trans, p, &idx, flags, l++);
 236         }
 237
 238         return ret;
 239 }
 240
 241 int bch2_trigger_reflink_p(struct btree_trans *trans,
 242                            enum btree_id btree_id, unsigned level,
 243                            struct bkey_s_c old,
 244                            struct bkey_s new,
 245                            enum btree_iter_update_trigger_flags flags)
 246 {
 247         if ((flags & BTREE_TRIGGER_transactional) &&
 248             (flags & BTREE_TRIGGER_insert)) {
 249                 struct bch_reflink_p *v = bkey_s_to_reflink_p(new).v;
 250
 251                 v->front_pad = v->back_pad = 0;
 252         }
 253
 254         return trigger_run_overwrite_then_insert(__trigger_reflink_p, trans, btree_id, level, old, new, flags);
 255 }
 256
 257 /* indirect extents */
 258
 259 int bch2_reflink_v_invalid(struct bch_fs *c, struct bkey_s_c k,
 260                            enum bch_validate_flags flags,
 261                            struct printbuf *err)
 262 {
 263         return bch2_bkey_ptrs_invalid(c, k, flags, err);
 264 }
 265
 266 void bch2_reflink_v_to_text(struct printbuf *out, struct bch_fs *c,
 267                             struct bkey_s_c k)
 268 {
 269         struct bkey_s_c_reflink_v r = bkey_s_c_to_reflink_v(k);
 270
 271         prt_printf(out, "refcount: %llu ", le64_to_cpu(r.v->refcount));
 272
 273         bch2_bkey_ptrs_to_text(out, c, k);
 274 }
 275
 276 #if 0
 277 Currently disabled, needs to be debugged:
 278
 279 bool bch2_reflink_v_merge(struct bch_fs *c, struct bkey_s _l, struct bkey_s_c _r)
 280 {
 281         struct bkey_s_reflink_v   l = bkey_s_to_reflink_v(_l);
 282         struct bkey_s_c_reflink_v r = bkey_s_c_to_reflink_v(_r);
 283
 284         return l.v->refcount == r.v->refcount && bch2_extent_merge(c, _l, _r);
 285 }
 286 #endif
 287
 288 static inline void
 289 check_indirect_extent_deleting(struct bkey_s new,
 290                                enum btree_iter_update_trigger_flags *flags)
 291 {
 292         if ((*flags & BTREE_TRIGGER_insert) && !*bkey_refcount(new)) {
 293                 new.k->type = KEY_TYPE_deleted;
 294                 new.k->size = 0;
 295                 set_bkey_val_u64s(new.k, 0);
 296                 *flags &= ~BTREE_TRIGGER_insert;
 297         }
 298 }
 299
 300 int bch2_trigger_reflink_v(struct btree_trans *trans,
 301                            enum btree_id btree_id, unsigned level,
 302                            struct bkey_s_c old, struct bkey_s new,
 303                            enum btree_iter_update_trigger_flags flags)
 304 {
 305         if ((flags & BTREE_TRIGGER_transactional) &&
 306             (flags & BTREE_TRIGGER_insert))
 307                 check_indirect_extent_deleting(new, &flags);
 308
 309         return bch2_trigger_extent(trans, btree_id, level, old, new, flags);
 310 }
 311
 312 /* indirect inline data */
 313
 314 int bch2_indirect_inline_data_invalid(struct bch_fs *c, struct bkey_s_c k,
 315                                       enum bch_validate_flags flags,
 316                                       struct printbuf *err)
 317 {
 318         return 0;
 319 }
 320
 321 void bch2_indirect_inline_data_to_text(struct printbuf *out,
 322                                        struct bch_fs *c, struct bkey_s_c k)
 323 {
 324         struct bkey_s_c_indirect_inline_data d = bkey_s_c_to_indirect_inline_data(k);
 325         unsigned datalen = bkey_inline_data_bytes(k.k);
 326
 327         prt_printf(out, "refcount %llu datalen %u: %*phN",
 328                le64_to_cpu(d.v->refcount), datalen,
 329                min(datalen, 32U), d.v->data);
 330 }
 331
 332 int bch2_trigger_indirect_inline_data(struct btree_trans *trans,
 333                               enum btree_id btree_id, unsigned level,
 334                               struct bkey_s_c old, struct bkey_s new,
 335                               enum btree_iter_update_trigger_flags flags)
 336 {
 337         check_indirect_extent_deleting(new, &flags);
 338
 339         return 0;
 340 }
 341
 342 static int bch2_make_extent_indirect(struct btree_trans *trans,
 343                                      struct btree_iter *extent_iter,
 344                                      struct bkey_i *orig)
 345 {
 346         struct bch_fs *c = trans->c;
 347         struct btree_iter reflink_iter = { NULL };
 348         struct bkey_s_c k;
 349         struct bkey_i *r_v;
 350         struct bkey_i_reflink_p *r_p;
 351         __le64 *refcount;
 352         int ret;
 353
 354         if (orig->k.type == KEY_TYPE_inline_data)
 355                 bch2_check_set_feature(c, BCH_FEATURE_reflink_inline_data);
 356
 357         bch2_trans_iter_init(trans, &reflink_iter, BTREE_ID_reflink, POS_MAX,
 358                              BTREE_ITER_intent);
 359         k = bch2_btree_iter_peek_prev(&reflink_iter);
 360         ret = bkey_err(k);
 361         if (ret)
 362                 goto err;
 363
 364         r_v = bch2_trans_kmalloc(trans, sizeof(__le64) + bkey_bytes(&orig->k));
 365         ret = PTR_ERR_OR_ZERO(r_v);
 366         if (ret)
 367                 goto err;
 368
 369         bkey_init(&r_v->k);
 370         r_v->k.type     = bkey_type_to_indirect(&orig->k);
 371         r_v->k.p        = reflink_iter.pos;
 372         bch2_key_resize(&r_v->k, orig->k.size);
 373         r_v->k.version  = orig->k.version;
 374
 375         set_bkey_val_bytes(&r_v->k, sizeof(__le64) + bkey_val_bytes(&orig->k));
 376
 377         refcount        = bkey_refcount(bkey_i_to_s(r_v));
 378         *refcount       = 0;
 379         memcpy(refcount + 1, &orig->v, bkey_val_bytes(&orig->k));
 380
 381         ret = bch2_trans_update(trans, &reflink_iter, r_v, 0);
 382         if (ret)
 383                 goto err;
 384
 385         /*
 386          * orig is in a bkey_buf which statically allocates 5 64s for the val,
 387          * so we know it will be big enough:
 388          */
 389         orig->k.type = KEY_TYPE_reflink_p;
 390         r_p = bkey_i_to_reflink_p(orig);
 391         set_bkey_val_bytes(&r_p->k, sizeof(r_p->v));
 392
 393         /* FORTIFY_SOURCE is broken here, and doesn't provide unsafe_memset() */
 394 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
 395         __underlying_memset(&r_p->v, 0, sizeof(r_p->v));
 396 #else
 397         memset(&r_p->v, 0, sizeof(r_p->v));
 398 #endif
 399
 400         r_p->v.idx = cpu_to_le64(bkey_start_offset(&r_v->k));
 401
 402         ret = bch2_trans_update(trans, extent_iter, &r_p->k_i,
 403                                 BTREE_UPDATE_internal_snapshot_node);
 404 err:
 405         bch2_trans_iter_exit(trans, &reflink_iter);
 406
 407         return ret;
 408 }
 409
 410 static struct bkey_s_c get_next_src(struct btree_iter *iter, struct bpos end)
 411 {
 412         struct bkey_s_c k;
 413         int ret;
 414
 415         for_each_btree_key_upto_continue_norestart(*iter, end, 0, k, ret) {
 416                 if (bkey_extent_is_unwritten(k))
 417                         continue;
 418
 419                 if (bkey_extent_is_data(k.k))
 420                         return k;
 421         }
 422
 423         if (bkey_ge(iter->pos, end))
 424                 bch2_btree_iter_set_pos(iter, end);
 425         return ret ? bkey_s_c_err(ret) : bkey_s_c_null;
 426 }
 427
 428 s64 bch2_remap_range(struct bch_fs *c,
 429                      subvol_inum dst_inum, u64 dst_offset,
 430                      subvol_inum src_inum, u64 src_offset,
 431                      u64 remap_sectors,
 432                      u64 new_i_size, s64 *i_sectors_delta)
 433 {
 434         struct btree_trans *trans;
 435         struct btree_iter dst_iter, src_iter;
 436         struct bkey_s_c src_k;
 437         struct bkey_buf new_dst, new_src;
 438         struct bpos dst_start = POS(dst_inum.inum, dst_offset);
 439         struct bpos src_start = POS(src_inum.inum, src_offset);
 440         struct bpos dst_end = dst_start, src_end = src_start;
 441         struct bch_io_opts opts;
 442         struct bpos src_want;
 443         u64 dst_done = 0;
 444         u32 dst_snapshot, src_snapshot;
 445         int ret = 0, ret2 = 0;
 446
 447         if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_reflink))
 448                 return -BCH_ERR_erofs_no_writes;
 449
 450         bch2_check_set_feature(c, BCH_FEATURE_reflink);
 451
 452         dst_end.offset += remap_sectors;
 453         src_end.offset += remap_sectors;
 454
 455         bch2_bkey_buf_init(&new_dst);
 456         bch2_bkey_buf_init(&new_src);
 457         trans = bch2_trans_get(c);
 458
 459         ret = bch2_inum_opts_get(trans, src_inum, &opts);
 460         if (ret)
 461                 goto err;
 462
 463         bch2_trans_iter_init(trans, &src_iter, BTREE_ID_extents, src_start,
 464                              BTREE_ITER_intent);
 465         bch2_trans_iter_init(trans, &dst_iter, BTREE_ID_extents, dst_start,
 466                              BTREE_ITER_intent);
 467
 468         while ((ret == 0 ||
 469                 bch2_err_matches(ret, BCH_ERR_transaction_restart)) &&
 470                bkey_lt(dst_iter.pos, dst_end)) {
 471                 struct disk_reservation disk_res = { 0 };
 472
 473                 bch2_trans_begin(trans);
 474
 475                 if (fatal_signal_pending(current)) {
 476                         ret = -EINTR;
 477                         break;
 478                 }
 479
 480                 ret = bch2_subvolume_get_snapshot(trans, src_inum.subvol,
 481                                                   &src_snapshot);
 482                 if (ret)
 483                         continue;
 484
 485                 bch2_btree_iter_set_snapshot(&src_iter, src_snapshot);
 486
 487                 ret = bch2_subvolume_get_snapshot(trans, dst_inum.subvol,
 488                                                   &dst_snapshot);
 489                 if (ret)
 490                         continue;
 491
 492                 bch2_btree_iter_set_snapshot(&dst_iter, dst_snapshot);
 493
 494                 if (dst_inum.inum < src_inum.inum) {
 495                         /* Avoid some lock cycle transaction restarts */
 496                         ret = bch2_btree_iter_traverse(&dst_iter);
 497                         if (ret)
 498                                 continue;
 499                 }
 500
 501                 dst_done = dst_iter.pos.offset - dst_start.offset;
 502                 src_want = POS(src_start.inode, src_start.offset + dst_done);
 503                 bch2_btree_iter_set_pos(&src_iter, src_want);
 504
 505                 src_k = get_next_src(&src_iter, src_end);
 506                 ret = bkey_err(src_k);
 507                 if (ret)
 508                         continue;
 509
 510                 if (bkey_lt(src_want, src_iter.pos)) {
 511                         ret = bch2_fpunch_at(trans, &dst_iter, dst_inum,
 512                                         min(dst_end.offset,
 513                                             dst_iter.pos.offset +
 514                                             src_iter.pos.offset - src_want.offset),
 515                                         i_sectors_delta);
 516                         continue;
 517                 }
 518
 519                 if (src_k.k->type != KEY_TYPE_reflink_p) {
 520                         bch2_btree_iter_set_pos_to_extent_start(&src_iter);
 521
 522                         bch2_bkey_buf_reassemble(&new_src, c, src_k);
 523                         src_k = bkey_i_to_s_c(new_src.k);
 524
 525                         ret = bch2_make_extent_indirect(trans, &src_iter,
 526                                                 new_src.k);
 527                         if (ret)
 528                                 continue;
 529
 530                         BUG_ON(src_k.k->type != KEY_TYPE_reflink_p);
 531                 }
 532
 533                 if (src_k.k->type == KEY_TYPE_reflink_p) {
 534                         struct bkey_s_c_reflink_p src_p =
 535                                 bkey_s_c_to_reflink_p(src_k);
 536                         struct bkey_i_reflink_p *dst_p =
 537                                 bkey_reflink_p_init(new_dst.k);
 538
 539                         u64 offset = le64_to_cpu(src_p.v->idx) +
 540                                 (src_want.offset -
 541                                  bkey_start_offset(src_k.k));
 542
 543                         dst_p->v.idx = cpu_to_le64(offset);
 544                 } else {
 545                         BUG();
 546                 }
 547
 548                 new_dst.k->k.p = dst_iter.pos;
 549                 bch2_key_resize(&new_dst.k->k,
 550                                 min(src_k.k->p.offset - src_want.offset,
 551                                     dst_end.offset - dst_iter.pos.offset));
 552
 553                 ret =   bch2_bkey_set_needs_rebalance(c, new_dst.k, &opts) ?:
 554                         bch2_extent_update(trans, dst_inum, &dst_iter,
 555                                         new_dst.k, &disk_res,
 556                                         new_i_size, i_sectors_delta,
 557                                         true);
 558                 bch2_disk_reservation_put(c, &disk_res);
 559         }
 560         bch2_trans_iter_exit(trans, &dst_iter);
 561         bch2_trans_iter_exit(trans, &src_iter);
 562
 563         BUG_ON(!ret && !bkey_eq(dst_iter.pos, dst_end));
 564         BUG_ON(bkey_gt(dst_iter.pos, dst_end));
 565
 566         dst_done = dst_iter.pos.offset - dst_start.offset;
 567         new_i_size = min(dst_iter.pos.offset << 9, new_i_size);
 568
 569         do {
 570                 struct bch_inode_unpacked inode_u;
 571                 struct btree_iter inode_iter = { NULL };
 572
 573                 bch2_trans_begin(trans);
 574
 575                 ret2 = bch2_inode_peek(trans, &inode_iter, &inode_u,
 576                                        dst_inum, BTREE_ITER_intent);
 577
 578                 if (!ret2 &&
 579                     inode_u.bi_size < new_i_size) {
 580                         inode_u.bi_size = new_i_size;
 581                         ret2  = bch2_inode_write(trans, &inode_iter, &inode_u) ?:
 582                                 bch2_trans_commit(trans, NULL, NULL,
 583                                                   BCH_TRANS_COMMIT_no_enospc);
 584                 }
 585
 586                 bch2_trans_iter_exit(trans, &inode_iter);
 587         } while (bch2_err_matches(ret2, BCH_ERR_transaction_restart));
 588 err:
 589         bch2_trans_put(trans);
 590         bch2_bkey_buf_exit(&new_src, c);
 591         bch2_bkey_buf_exit(&new_dst, c);
 592
 593         bch2_write_ref_put(c, BCH_WRITE_REF_reflink);
 594
 595         return dst_done ?: ret ?: ret2;
 596 }