git.sesse.net Git - bcachefs-tools-debian/blob - libbcachefs/extents.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _BCACHEFS_EXTENTS_H
   3 #define _BCACHEFS_EXTENTS_H
   4
   5 #include "bcachefs.h"
   6 #include "bkey.h"
   7 #include "extents_types.h"
   8
   9 struct bch_fs;
  10 struct btree_trans;
  11
  12 /* extent entries: */
  13
  14 #define extent_entry_last(_e)                                           \
  15         ((typeof(&(_e).v->start[0])) bkey_val_end(_e))
  16
  17 #define entry_to_ptr(_entry)                                            \
  18 ({                                                                      \
  19         EBUG_ON((_entry) && !extent_entry_is_ptr(_entry));              \
  20                                                                         \
  21         __builtin_choose_expr(                                          \
  22                 type_is_exact(_entry, const union bch_extent_entry *),  \
  23                 (const struct bch_extent_ptr *) (_entry),               \
  24                 (struct bch_extent_ptr *) (_entry));                    \
  25 })
  26
  27 /* downcast, preserves const */
  28 #define to_entry(_entry)                                                \
  29 ({                                                                      \
  30         BUILD_BUG_ON(!type_is(_entry, union bch_extent_crc *) &&        \
  31                      !type_is(_entry, struct bch_extent_ptr *) &&       \
  32                      !type_is(_entry, struct bch_extent_stripe_ptr *)); \
  33                                                                         \
  34         __builtin_choose_expr(                                          \
  35                 (type_is_exact(_entry, const union bch_extent_crc *) || \
  36                  type_is_exact(_entry, const struct bch_extent_ptr *) ||\
  37                  type_is_exact(_entry, const struct bch_extent_stripe_ptr *)),\
  38                 (const union bch_extent_entry *) (_entry),              \
  39                 (union bch_extent_entry *) (_entry));                   \
  40 })
  41
  42 #define extent_entry_next(_entry)                                       \
  43         ((typeof(_entry)) ((void *) (_entry) + extent_entry_bytes(_entry)))
  44
  45 static inline unsigned
  46 __extent_entry_type(const union bch_extent_entry *e)
  47 {
  48         return e->type ? __ffs(e->type) : BCH_EXTENT_ENTRY_MAX;
  49 }
  50
  51 static inline enum bch_extent_entry_type
  52 extent_entry_type(const union bch_extent_entry *e)
  53 {
  54         int ret = __ffs(e->type);
  55
  56         EBUG_ON(ret < 0 || ret >= BCH_EXTENT_ENTRY_MAX);
  57
  58         return ret;
  59 }
  60
  61 static inline size_t extent_entry_bytes(const union bch_extent_entry *entry)
  62 {
  63         switch (extent_entry_type(entry)) {
  64 #define x(f, n)                                         \
  65         case BCH_EXTENT_ENTRY_##f:                      \
  66                 return sizeof(struct bch_extent_##f);
  67         BCH_EXTENT_ENTRY_TYPES()
  68 #undef x
  69         default:
  70                 BUG();
  71         }
  72 }
  73
  74 static inline size_t extent_entry_u64s(const union bch_extent_entry *entry)
  75 {
  76         return extent_entry_bytes(entry) / sizeof(u64);
  77 }
  78
  79 static inline bool extent_entry_is_ptr(const union bch_extent_entry *e)
  80 {
  81         switch (extent_entry_type(e)) {
  82         case BCH_EXTENT_ENTRY_ptr:
  83                 return true;
  84         default:
  85                 return false;
  86         }
  87 }
  88
  89 static inline bool extent_entry_is_crc(const union bch_extent_entry *e)
  90 {
  91         switch (extent_entry_type(e)) {
  92         case BCH_EXTENT_ENTRY_crc32:
  93         case BCH_EXTENT_ENTRY_crc64:
  94         case BCH_EXTENT_ENTRY_crc128:
  95                 return true;
  96         default:
  97                 return false;
  98         }
  99 }
 100
 101 union bch_extent_crc {
 102         u8                              type;
 103         struct bch_extent_crc32         crc32;
 104         struct bch_extent_crc64         crc64;
 105         struct bch_extent_crc128        crc128;
 106 };
 107
 108 #define __entry_to_crc(_entry)                                          \
 109         __builtin_choose_expr(                                          \
 110                 type_is_exact(_entry, const union bch_extent_entry *),  \
 111                 (const union bch_extent_crc *) (_entry),                \
 112                 (union bch_extent_crc *) (_entry))
 113
 114 #define entry_to_crc(_entry)                                            \
 115 ({                                                                      \
 116         EBUG_ON((_entry) && !extent_entry_is_crc(_entry));              \
 117                                                                         \
 118         __entry_to_crc(_entry);                                         \
 119 })
 120
 121 static inline struct bch_extent_crc_unpacked
 122 bch2_extent_crc_unpack(const struct bkey *k, const union bch_extent_crc *crc)
 123 {
 124 #define common_fields(_crc)                                             \
 125                 .csum_type              = _crc.csum_type,               \
 126                 .compression_type       = _crc.compression_type,        \
 127                 .compressed_size        = _crc._compressed_size + 1,    \
 128                 .uncompressed_size      = _crc._uncompressed_size + 1,  \
 129                 .offset                 = _crc.offset,                  \
 130                 .live_size              = k->size
 131
 132         if (!crc)
 133                 return (struct bch_extent_crc_unpacked) {
 134                         .compressed_size        = k->size,
 135                         .uncompressed_size      = k->size,
 136                         .live_size              = k->size,
 137                 };
 138
 139         switch (extent_entry_type(to_entry(crc))) {
 140         case BCH_EXTENT_ENTRY_crc32: {
 141                 struct bch_extent_crc_unpacked ret = (struct bch_extent_crc_unpacked) {
 142                         common_fields(crc->crc32),
 143                 };
 144
 145                 *((__le32 *) &ret.csum.lo) = crc->crc32.csum;
 146
 147                 memcpy(&ret.csum.lo, &crc->crc32.csum,
 148                        sizeof(crc->crc32.csum));
 149
 150                 return ret;
 151         }
 152         case BCH_EXTENT_ENTRY_crc64: {
 153                 struct bch_extent_crc_unpacked ret = (struct bch_extent_crc_unpacked) {
 154                         common_fields(crc->crc64),
 155                         .nonce                  = crc->crc64.nonce,
 156                         .csum.lo                = (__force __le64) crc->crc64.csum_lo,
 157                 };
 158
 159                 *((__le16 *) &ret.csum.hi) = crc->crc64.csum_hi;
 160
 161                 return ret;
 162         }
 163         case BCH_EXTENT_ENTRY_crc128: {
 164                 struct bch_extent_crc_unpacked ret = (struct bch_extent_crc_unpacked) {
 165                         common_fields(crc->crc128),
 166                         .nonce                  = crc->crc128.nonce,
 167                         .csum                   = crc->crc128.csum,
 168                 };
 169
 170                 return ret;
 171         }
 172         default:
 173                 BUG();
 174         }
 175 #undef common_fields
 176 }
 177
 178 static inline bool crc_is_compressed(struct bch_extent_crc_unpacked crc)
 179 {
 180         return (crc.compression_type != BCH_COMPRESSION_TYPE_none &&
 181                 crc.compression_type != BCH_COMPRESSION_TYPE_incompressible);
 182 }
 183
 184 /* bkey_ptrs: generically over any key type that has ptrs */
 185
 186 struct bkey_ptrs_c {
 187         const union bch_extent_entry    *start;
 188         const union bch_extent_entry    *end;
 189 };
 190
 191 struct bkey_ptrs {
 192         union bch_extent_entry  *start;
 193         union bch_extent_entry  *end;
 194 };
 195
 196 static inline struct bkey_ptrs_c bch2_bkey_ptrs_c(struct bkey_s_c k)
 197 {
 198         switch (k.k->type) {
 199         case KEY_TYPE_btree_ptr: {
 200                 struct bkey_s_c_btree_ptr e = bkey_s_c_to_btree_ptr(k);
 201                 return (struct bkey_ptrs_c) {
 202                         to_entry(&e.v->start[0]),
 203                         to_entry(extent_entry_last(e))
 204                 };
 205         }
 206         case KEY_TYPE_extent: {
 207                 struct bkey_s_c_extent e = bkey_s_c_to_extent(k);
 208                 return (struct bkey_ptrs_c) {
 209                         e.v->start,
 210                         extent_entry_last(e)
 211                 };
 212         }
 213         case KEY_TYPE_stripe: {
 214                 struct bkey_s_c_stripe s = bkey_s_c_to_stripe(k);
 215                 return (struct bkey_ptrs_c) {
 216                         to_entry(&s.v->ptrs[0]),
 217                         to_entry(&s.v->ptrs[s.v->nr_blocks]),
 218                 };
 219         }
 220         case KEY_TYPE_reflink_v: {
 221                 struct bkey_s_c_reflink_v r = bkey_s_c_to_reflink_v(k);
 222
 223                 return (struct bkey_ptrs_c) {
 224                         r.v->start,
 225                         bkey_val_end(r),
 226                 };
 227         }
 228         default:
 229                 return (struct bkey_ptrs_c) { NULL, NULL };
 230         }
 231 }
 232
 233 static inline struct bkey_ptrs bch2_bkey_ptrs(struct bkey_s k)
 234 {
 235         struct bkey_ptrs_c p = bch2_bkey_ptrs_c(k.s_c);
 236
 237         return (struct bkey_ptrs) {
 238                 (void *) p.start,
 239                 (void *) p.end
 240         };
 241 }
 242
 243 #define __bkey_extent_entry_for_each_from(_start, _end, _entry)         \
 244         for ((_entry) = (_start);                                       \
 245              (_entry) < (_end);                                         \
 246              (_entry) = extent_entry_next(_entry))
 247
 248 #define __bkey_ptr_next(_ptr, _end)                                     \
 249 ({                                                                      \
 250         typeof(_end) _entry;                                            \
 251                                                                         \
 252         __bkey_extent_entry_for_each_from(to_entry(_ptr), _end, _entry) \
 253                 if (extent_entry_is_ptr(_entry))                        \
 254                         break;                                          \
 255                                                                         \
 256         _entry < (_end) ? entry_to_ptr(_entry) : NULL;                  \
 257 })
 258
 259 #define bkey_extent_entry_for_each_from(_p, _entry, _start)             \
 260         __bkey_extent_entry_for_each_from(_start, (_p).end, _entry)
 261
 262 #define bkey_extent_entry_for_each(_p, _entry)                          \
 263         bkey_extent_entry_for_each_from(_p, _entry, _p.start)
 264
 265 #define __bkey_for_each_ptr(_start, _end, _ptr)                         \
 266         for ((_ptr) = (_start);                                         \
 267              ((_ptr) = __bkey_ptr_next(_ptr, _end));                    \
 268              (_ptr)++)
 269
 270 #define bkey_ptr_next(_p, _ptr)                                         \
 271         __bkey_ptr_next(_ptr, (_p).end)
 272
 273 #define bkey_for_each_ptr(_p, _ptr)                                     \
 274         __bkey_for_each_ptr(&(_p).start->ptr, (_p).end, _ptr)
 275
 276 #define __bkey_ptr_next_decode(_k, _end, _ptr, _entry)                  \
 277 ({                                                                      \
 278         __label__ out;                                                  \
 279                                                                         \
 280         (_ptr).idx      = 0;                                            \
 281         (_ptr).has_ec   = false;                                        \
 282                                                                         \
 283         __bkey_extent_entry_for_each_from(_entry, _end, _entry)         \
 284                 switch (extent_entry_type(_entry)) {                    \
 285                 case BCH_EXTENT_ENTRY_ptr:                              \
 286                         (_ptr).ptr              = _entry->ptr;          \
 287                         goto out;                                       \
 288                 case BCH_EXTENT_ENTRY_crc32:                            \
 289                 case BCH_EXTENT_ENTRY_crc64:                            \
 290                 case BCH_EXTENT_ENTRY_crc128:                           \
 291                         (_ptr).crc = bch2_extent_crc_unpack(_k,         \
 292                                         entry_to_crc(_entry));          \
 293                         break;                                          \
 294                 case BCH_EXTENT_ENTRY_stripe_ptr:                       \
 295                         (_ptr).ec = _entry->stripe_ptr;                 \
 296                         (_ptr).has_ec   = true;                         \
 297                         break;                                          \
 298                 }                                                       \
 299 out:                                                                    \
 300         _entry < (_end);                                                \
 301 })
 302
 303 #define __bkey_for_each_ptr_decode(_k, _start, _end, _ptr, _entry)      \
 304         for ((_ptr).crc = bch2_extent_crc_unpack(_k, NULL),             \
 305              (_entry) = _start;                                         \
 306              __bkey_ptr_next_decode(_k, _end, _ptr, _entry);            \
 307              (_entry) = extent_entry_next(_entry))
 308
 309 #define bkey_for_each_ptr_decode(_k, _p, _ptr, _entry)                  \
 310         __bkey_for_each_ptr_decode(_k, (_p).start, (_p).end,            \
 311                                    _ptr, _entry)
 312
 313 #define bkey_crc_next(_k, _start, _end, _crc, _iter)                    \
 314 ({                                                                      \
 315         __bkey_extent_entry_for_each_from(_iter, _end, _iter)           \
 316                 if (extent_entry_is_crc(_iter)) {                       \
 317                         (_crc) = bch2_extent_crc_unpack(_k,             \
 318                                                 entry_to_crc(_iter));   \
 319                         break;                                          \
 320                 }                                                       \
 321                                                                         \
 322         (_iter) < (_end);                                               \
 323 })
 324
 325 #define __bkey_for_each_crc(_k, _start, _end, _crc, _iter)              \
 326         for ((_crc) = bch2_extent_crc_unpack(_k, NULL),                 \
 327              (_iter) = (_start);                                        \
 328              bkey_crc_next(_k, _start, _end, _crc, _iter);              \
 329              (_iter) = extent_entry_next(_iter))
 330
 331 #define bkey_for_each_crc(_k, _p, _crc, _iter)                          \
 332         __bkey_for_each_crc(_k, (_p).start, (_p).end, _crc, _iter)
 333
 334 /* Iterate over pointers in KEY_TYPE_extent: */
 335
 336 #define extent_for_each_entry_from(_e, _entry, _start)                  \
 337         __bkey_extent_entry_for_each_from(_start,                       \
 338                                 extent_entry_last(_e),_entry)
 339
 340 #define extent_for_each_entry(_e, _entry)                               \
 341         extent_for_each_entry_from(_e, _entry, (_e).v->start)
 342
 343 #define extent_ptr_next(_e, _ptr)                                       \
 344         __bkey_ptr_next(_ptr, extent_entry_last(_e))
 345
 346 #define extent_for_each_ptr(_e, _ptr)                                   \
 347         __bkey_for_each_ptr(&(_e).v->start->ptr, extent_entry_last(_e), _ptr)
 348
 349 #define extent_for_each_ptr_decode(_e, _ptr, _entry)                    \
 350         __bkey_for_each_ptr_decode((_e).k, (_e).v->start,               \
 351                                    extent_entry_last(_e), _ptr, _entry)
 352
 353 /* utility code common to all keys with pointers: */
 354
 355 void bch2_mark_io_failure(struct bch_io_failures *,
 356                           struct extent_ptr_decoded *);
 357 int bch2_bkey_pick_read_device(struct bch_fs *, struct bkey_s_c,
 358                                struct bch_io_failures *,
 359                                struct extent_ptr_decoded *);
 360
 361 /* KEY_TYPE_btree_ptr: */
 362
 363 const char *bch2_btree_ptr_invalid(const struct bch_fs *, struct bkey_s_c);
 364 void bch2_btree_ptr_debugcheck(struct bch_fs *, struct bkey_s_c);
 365 void bch2_btree_ptr_to_text(struct printbuf *, struct bch_fs *,
 366                             struct bkey_s_c);
 367
 368 #define bch2_bkey_ops_btree_ptr (struct bkey_ops) {             \
 369         .key_invalid    = bch2_btree_ptr_invalid,               \
 370         .key_debugcheck = bch2_btree_ptr_debugcheck,            \
 371         .val_to_text    = bch2_btree_ptr_to_text,               \
 372         .swab           = bch2_ptr_swab,                        \
 373 }
 374
 375 /* KEY_TYPE_extent: */
 376
 377 const char *bch2_extent_invalid(const struct bch_fs *, struct bkey_s_c);
 378 void bch2_extent_debugcheck(struct bch_fs *, struct bkey_s_c);
 379 void bch2_extent_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 380 enum merge_result bch2_extent_merge(struct bch_fs *,
 381                                     struct bkey_s, struct bkey_s);
 382
 383 #define bch2_bkey_ops_extent (struct bkey_ops) {                \
 384         .key_invalid    = bch2_extent_invalid,                  \
 385         .key_debugcheck = bch2_extent_debugcheck,               \
 386         .val_to_text    = bch2_extent_to_text,                  \
 387         .swab           = bch2_ptr_swab,                        \
 388         .key_normalize  = bch2_extent_normalize,                \
 389         .key_merge      = bch2_extent_merge,                    \
 390 }
 391
 392 /* KEY_TYPE_reservation: */
 393
 394 const char *bch2_reservation_invalid(const struct bch_fs *, struct bkey_s_c);
 395 void bch2_reservation_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 396 enum merge_result bch2_reservation_merge(struct bch_fs *,
 397                                          struct bkey_s, struct bkey_s);
 398
 399 #define bch2_bkey_ops_reservation (struct bkey_ops) {           \
 400         .key_invalid    = bch2_reservation_invalid,             \
 401         .val_to_text    = bch2_reservation_to_text,             \
 402         .key_merge      = bch2_reservation_merge,               \
 403 }
 404
 405 /* Extent checksum entries: */
 406
 407 bool bch2_can_narrow_extent_crcs(struct bkey_s_c,
 408                                  struct bch_extent_crc_unpacked);
 409 bool bch2_bkey_narrow_crcs(struct bkey_i *, struct bch_extent_crc_unpacked);
 410 void bch2_extent_crc_append(struct bkey_i *,
 411                             struct bch_extent_crc_unpacked);
 412
 413 /* Generic code for keys with pointers: */
 414
 415 static inline bool bkey_extent_is_direct_data(const struct bkey *k)
 416 {
 417         switch (k->type) {
 418         case KEY_TYPE_btree_ptr:
 419         case KEY_TYPE_extent:
 420         case KEY_TYPE_reflink_v:
 421                 return true;
 422         default:
 423                 return false;
 424         }
 425 }
 426
 427 static inline bool bkey_extent_is_data(const struct bkey *k)
 428 {
 429         return bkey_extent_is_direct_data(k) ||
 430                 k->type == KEY_TYPE_inline_data ||
 431                 k->type == KEY_TYPE_reflink_p;
 432 }
 433
 434 /*
 435  * Should extent be counted under inode->i_sectors?
 436  */
 437 static inline bool bkey_extent_is_allocation(const struct bkey *k)
 438 {
 439         switch (k->type) {
 440         case KEY_TYPE_extent:
 441         case KEY_TYPE_reservation:
 442         case KEY_TYPE_reflink_p:
 443         case KEY_TYPE_reflink_v:
 444         case KEY_TYPE_inline_data:
 445                 return true;
 446         default:
 447                 return false;
 448         }
 449 }
 450
 451 static inline struct bch_devs_list bch2_bkey_devs(struct bkey_s_c k)
 452 {
 453         struct bch_devs_list ret = (struct bch_devs_list) { 0 };
 454         struct bkey_ptrs_c p = bch2_bkey_ptrs_c(k);
 455         const struct bch_extent_ptr *ptr;
 456
 457         bkey_for_each_ptr(p, ptr)
 458                 ret.devs[ret.nr++] = ptr->dev;
 459
 460         return ret;
 461 }
 462
 463 static inline struct bch_devs_list bch2_bkey_dirty_devs(struct bkey_s_c k)
 464 {
 465         struct bch_devs_list ret = (struct bch_devs_list) { 0 };
 466         struct bkey_ptrs_c p = bch2_bkey_ptrs_c(k);
 467         const struct bch_extent_ptr *ptr;
 468
 469         bkey_for_each_ptr(p, ptr)
 470                 if (!ptr->cached)
 471                         ret.devs[ret.nr++] = ptr->dev;
 472
 473         return ret;
 474 }
 475
 476 static inline struct bch_devs_list bch2_bkey_cached_devs(struct bkey_s_c k)
 477 {
 478         struct bch_devs_list ret = (struct bch_devs_list) { 0 };
 479         struct bkey_ptrs_c p = bch2_bkey_ptrs_c(k);
 480         const struct bch_extent_ptr *ptr;
 481
 482         bkey_for_each_ptr(p, ptr)
 483                 if (ptr->cached)
 484                         ret.devs[ret.nr++] = ptr->dev;
 485
 486         return ret;
 487 }
 488
 489 unsigned bch2_bkey_nr_ptrs(struct bkey_s_c);
 490 unsigned bch2_bkey_nr_ptrs_allocated(struct bkey_s_c);
 491 unsigned bch2_bkey_nr_ptrs_fully_allocated(struct bkey_s_c);
 492 bool bch2_bkey_is_incompressible(struct bkey_s_c);
 493 unsigned bch2_bkey_sectors_compressed(struct bkey_s_c);
 494 bool bch2_check_range_allocated(struct bch_fs *, struct bpos, u64, unsigned);
 495 unsigned bch2_bkey_durability(struct bch_fs *, struct bkey_s_c);
 496
 497 void bch2_bkey_mark_replicas_cached(struct bch_fs *, struct bkey_s,
 498                                     unsigned, unsigned);
 499
 500 void bch2_bkey_append_ptr(struct bkey_i *, struct bch_extent_ptr);
 501 void bch2_extent_ptr_decoded_append(struct bkey_i *,
 502                                     struct extent_ptr_decoded *);
 503 union bch_extent_entry *bch2_bkey_drop_ptr(struct bkey_s,
 504                                            struct bch_extent_ptr *);
 505
 506 #define bch2_bkey_drop_ptrs(_k, _ptr, _cond)                            \
 507 do {                                                                    \
 508         struct bkey_ptrs _ptrs = bch2_bkey_ptrs(_k);                    \
 509                                                                         \
 510         _ptr = &_ptrs.start->ptr;                                       \
 511                                                                         \
 512         while ((_ptr = bkey_ptr_next(_ptrs, _ptr))) {                   \
 513                 if (_cond) {                                            \
 514                         _ptr = (void *) bch2_bkey_drop_ptr(_k, _ptr);   \
 515                         _ptrs = bch2_bkey_ptrs(_k);                     \
 516                         continue;                                       \
 517                 }                                                       \
 518                                                                         \
 519                 (_ptr)++;                                               \
 520         }                                                               \
 521 } while (0)
 522
 523 void bch2_bkey_drop_device(struct bkey_s, unsigned);
 524 const struct bch_extent_ptr *bch2_bkey_has_device(struct bkey_s_c, unsigned);
 525 bool bch2_bkey_has_target(struct bch_fs *, struct bkey_s_c, unsigned);
 526
 527 bool bch2_bkey_matches_ptr(struct bch_fs *, struct bkey_s_c,
 528                            struct bch_extent_ptr, u64);
 529
 530 bool bch2_extent_normalize(struct bch_fs *, struct bkey_s);
 531 void bch2_bkey_ptrs_to_text(struct printbuf *, struct bch_fs *,
 532                             struct bkey_s_c);
 533 const char *bch2_bkey_ptrs_invalid(const struct bch_fs *, struct bkey_s_c);
 534
 535 void bch2_ptr_swab(const struct bkey_format *, struct bkey_packed *);
 536
 537 /* Generic extent code: */
 538
 539 int bch2_cut_front_s(struct bpos, struct bkey_s);
 540 int bch2_cut_back_s(struct bpos, struct bkey_s);
 541
 542 static inline void bch2_cut_front(struct bpos where, struct bkey_i *k)
 543 {
 544         bch2_cut_front_s(where, bkey_i_to_s(k));
 545 }
 546
 547 static inline void bch2_cut_back(struct bpos where, struct bkey_i *k)
 548 {
 549         bch2_cut_back_s(where, bkey_i_to_s(k));
 550 }
 551
 552 /**
 553  * bch_key_resize - adjust size of @k
 554  *
 555  * bkey_start_offset(k) will be preserved, modifies where the extent ends
 556  */
 557 static inline void bch2_key_resize(struct bkey *k, unsigned new_size)
 558 {
 559         k->p.offset -= k->size;
 560         k->p.offset += new_size;
 561         k->size = new_size;
 562 }
 563
 564 /*
 565  * In extent_sort_fix_overlapping(), insert_fixup_extent(),
 566  * extent_merge_inline() - we're modifying keys in place that are packed. To do
 567  * that we have to unpack the key, modify the unpacked key - then this
 568  * copies/repacks the unpacked to the original as necessary.
 569  */
 570 static inline void extent_save(struct btree *b, struct bkey_packed *dst,
 571                                struct bkey *src)
 572 {
 573         struct bkey_format *f = &b->format;
 574         struct bkey_i *dst_unpacked;
 575
 576         if ((dst_unpacked = packed_to_bkey(dst)))
 577                 dst_unpacked->k = *src;
 578         else
 579                 BUG_ON(!bch2_bkey_pack_key(dst, src, f));
 580 }
 581
 582 #endif /* _BCACHEFS_EXTENTS_H */