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

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #include "bcachefs.h"
   4 #include "btree_key_cache.h"
   5 #include "bkey_methods.h"
   6 #include "btree_update.h"
   7 #include "buckets.h"
   8 #include "error.h"
   9 #include "extents.h"
  10 #include "extent_update.h"
  11 #include "inode.h"
  12 #include "str_hash.h"
  13 #include "subvolume.h"
  14 #include "varint.h"
  15
  16 #include <linux/random.h>
  17
  18 #include <asm/unaligned.h>
  19
  20 const char * const bch2_inode_opts[] = {
  21 #define x(name, ...)    #name,
  22         BCH_INODE_OPTS()
  23 #undef  x
  24         NULL,
  25 };
  26
  27 static const u8 byte_table[8] = { 1, 2, 3, 4, 6, 8, 10, 13 };
  28
  29 static int inode_decode_field(const u8 *in, const u8 *end,
  30                               u64 out[2], unsigned *out_bits)
  31 {
  32         __be64 be[2] = { 0, 0 };
  33         unsigned bytes, shift;
  34         u8 *p;
  35
  36         if (in >= end)
  37                 return -1;
  38
  39         if (!*in)
  40                 return -1;
  41
  42         /*
  43          * position of highest set bit indicates number of bytes:
  44          * shift = number of bits to remove in high byte:
  45          */
  46         shift   = 8 - __fls(*in); /* 1 <= shift <= 8 */
  47         bytes   = byte_table[shift - 1];
  48
  49         if (in + bytes > end)
  50                 return -1;
  51
  52         p = (u8 *) be + 16 - bytes;
  53         memcpy(p, in, bytes);
  54         *p ^= (1 << 8) >> shift;
  55
  56         out[0] = be64_to_cpu(be[0]);
  57         out[1] = be64_to_cpu(be[1]);
  58         *out_bits = out[0] ? 64 + fls64(out[0]) : fls64(out[1]);
  59
  60         return bytes;
  61 }
  62
  63 void bch2_inode_pack(struct bch_fs *c,
  64                      struct bkey_inode_buf *packed,
  65                      const struct bch_inode_unpacked *inode)
  66 {
  67         struct bkey_i_inode_v2 *k = &packed->inode;
  68         u8 *out = k->v.fields;
  69         u8 *end = (void *) &packed[1];
  70         u8 *last_nonzero_field = out;
  71         unsigned nr_fields = 0, last_nonzero_fieldnr = 0;
  72         unsigned bytes;
  73         int ret;
  74
  75         bkey_inode_v2_init(&packed->inode.k_i);
  76         packed->inode.k.p.offset        = inode->bi_inum;
  77         packed->inode.v.bi_journal_seq  = cpu_to_le64(inode->bi_journal_seq);
  78         packed->inode.v.bi_hash_seed    = inode->bi_hash_seed;
  79         packed->inode.v.bi_flags        = cpu_to_le64(inode->bi_flags);
  80         packed->inode.v.bi_flags        = cpu_to_le64(inode->bi_flags);
  81         packed->inode.v.bi_mode         = cpu_to_le16(inode->bi_mode);
  82
  83 #define x(_name, _bits)                                                 \
  84         nr_fields++;                                                    \
  85                                                                         \
  86         if (inode->_name) {                                             \
  87                 ret = bch2_varint_encode_fast(out, inode->_name);       \
  88                 out += ret;                                             \
  89                                                                         \
  90                 if (_bits > 64)                                         \
  91                         *out++ = 0;                                     \
  92                                                                         \
  93                 last_nonzero_field = out;                               \
  94                 last_nonzero_fieldnr = nr_fields;                       \
  95         } else {                                                        \
  96                 *out++ = 0;                                             \
  97                                                                         \
  98                 if (_bits > 64)                                         \
  99                         *out++ = 0;                                     \
 100         }
 101
 102         BCH_INODE_FIELDS()
 103 #undef  x
 104         BUG_ON(out > end);
 105
 106         out = last_nonzero_field;
 107         nr_fields = last_nonzero_fieldnr;
 108
 109         bytes = out - (u8 *) &packed->inode.v;
 110         set_bkey_val_bytes(&packed->inode.k, bytes);
 111         memset_u64s_tail(&packed->inode.v, 0, bytes);
 112
 113         SET_INODEv2_NR_FIELDS(&k->v, nr_fields);
 114
 115         if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) {
 116                 struct bch_inode_unpacked unpacked;
 117
 118                 int ret = bch2_inode_unpack(bkey_i_to_s_c(&packed->inode.k_i),
 119                                            &unpacked);
 120                 BUG_ON(ret);
 121                 BUG_ON(unpacked.bi_inum         != inode->bi_inum);
 122                 BUG_ON(unpacked.bi_hash_seed    != inode->bi_hash_seed);
 123                 BUG_ON(unpacked.bi_mode         != inode->bi_mode);
 124
 125 #define x(_name, _bits) if (unpacked._name != inode->_name)             \
 126                         panic("unpacked %llu should be %llu",           \
 127                               (u64) unpacked._name, (u64) inode->_name);
 128                 BCH_INODE_FIELDS()
 129 #undef  x
 130         }
 131 }
 132
 133 static noinline int bch2_inode_unpack_v1(struct bkey_s_c_inode inode,
 134                                 struct bch_inode_unpacked *unpacked)
 135 {
 136         const u8 *in = inode.v->fields;
 137         const u8 *end = bkey_val_end(inode);
 138         u64 field[2];
 139         unsigned fieldnr = 0, field_bits;
 140         int ret;
 141
 142 #define x(_name, _bits)                                 \
 143         if (fieldnr++ == INODE_NR_FIELDS(inode.v)) {                    \
 144                 memset(&unpacked->_name, 0,                             \
 145                        sizeof(*unpacked) -                              \
 146                        offsetof(struct bch_inode_unpacked, _name));     \
 147                 return 0;                                               \
 148         }                                                               \
 149                                                                         \
 150         ret = inode_decode_field(in, end, field, &field_bits);          \
 151         if (ret < 0)                                                    \
 152                 return ret;                                             \
 153                                                                         \
 154         if (field_bits > sizeof(unpacked->_name) * 8)                   \
 155                 return -1;                                              \
 156                                                                         \
 157         unpacked->_name = field[1];                                     \
 158         in += ret;
 159
 160         BCH_INODE_FIELDS()
 161 #undef  x
 162
 163         /* XXX: signal if there were more fields than expected? */
 164         return 0;
 165 }
 166
 167 static int bch2_inode_unpack_v2(struct bch_inode_unpacked *unpacked,
 168                                 const u8 *in, const u8 *end,
 169                                 unsigned nr_fields)
 170 {
 171         unsigned fieldnr = 0;
 172         int ret;
 173         u64 v[2];
 174
 175 #define x(_name, _bits)                                                 \
 176         if (fieldnr < nr_fields) {                                      \
 177                 ret = bch2_varint_decode_fast(in, end, &v[0]);          \
 178                 if (ret < 0)                                            \
 179                         return ret;                                     \
 180                 in += ret;                                              \
 181                                                                         \
 182                 if (_bits > 64) {                                       \
 183                         ret = bch2_varint_decode_fast(in, end, &v[1]);  \
 184                         if (ret < 0)                                    \
 185                                 return ret;                             \
 186                         in += ret;                                      \
 187                 } else {                                                \
 188                         v[1] = 0;                                       \
 189                 }                                                       \
 190         } else {                                                        \
 191                 v[0] = v[1] = 0;                                        \
 192         }                                                               \
 193                                                                         \
 194         unpacked->_name = v[0];                                         \
 195         if (v[1] || v[0] != unpacked->_name)                            \
 196                 return -1;                                              \
 197         fieldnr++;
 198
 199         BCH_INODE_FIELDS()
 200 #undef  x
 201
 202         /* XXX: signal if there were more fields than expected? */
 203         return 0;
 204 }
 205
 206 int bch2_inode_unpack(struct bkey_s_c k,
 207                       struct bch_inode_unpacked *unpacked)
 208 {
 209         switch (k.k->type) {
 210         case KEY_TYPE_inode: {
 211                 struct bkey_s_c_inode inode = bkey_s_c_to_inode(k);
 212
 213                 unpacked->bi_inum       = inode.k->p.offset;
 214                 unpacked->bi_journal_seq= 0;
 215                 unpacked->bi_hash_seed  = inode.v->bi_hash_seed;
 216                 unpacked->bi_flags      = le32_to_cpu(inode.v->bi_flags);
 217                 unpacked->bi_mode       = le16_to_cpu(inode.v->bi_mode);
 218
 219                 if (INODE_NEW_VARINT(inode.v)) {
 220                         return bch2_inode_unpack_v2(unpacked, inode.v->fields,
 221                                                     bkey_val_end(inode),
 222                                                     INODE_NR_FIELDS(inode.v));
 223                 } else {
 224                         return bch2_inode_unpack_v1(inode, unpacked);
 225                 }
 226                 break;
 227         }
 228         case KEY_TYPE_inode_v2: {
 229                 struct bkey_s_c_inode_v2 inode = bkey_s_c_to_inode_v2(k);
 230
 231                 unpacked->bi_inum       = inode.k->p.offset;
 232                 unpacked->bi_journal_seq= le64_to_cpu(inode.v->bi_journal_seq);
 233                 unpacked->bi_hash_seed  = inode.v->bi_hash_seed;
 234                 unpacked->bi_flags      = le64_to_cpu(inode.v->bi_flags);
 235                 unpacked->bi_mode       = le16_to_cpu(inode.v->bi_mode);
 236
 237                 return bch2_inode_unpack_v2(unpacked, inode.v->fields,
 238                                             bkey_val_end(inode),
 239                                             INODEv2_NR_FIELDS(inode.v));
 240         }
 241         default:
 242                 BUG();
 243         }
 244 }
 245
 246 int bch2_inode_peek(struct btree_trans *trans,
 247                     struct btree_iter *iter,
 248                     struct bch_inode_unpacked *inode,
 249                     subvol_inum inum, unsigned flags)
 250 {
 251         struct bkey_s_c k;
 252         u32 snapshot;
 253         int ret;
 254
 255         if (0 && trans->c->opts.inodes_use_key_cache)
 256                 flags |= BTREE_ITER_CACHED;
 257
 258         ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
 259         if (ret)
 260                 return ret;
 261
 262         bch2_trans_iter_init(trans, iter, BTREE_ID_inodes,
 263                              SPOS(0, inum.inum, snapshot), flags);
 264         k = bch2_btree_iter_peek_slot(iter);
 265         ret = bkey_err(k);
 266         if (ret)
 267                 goto err;
 268
 269         ret = bkey_is_inode(k.k) ? 0 : -ENOENT;
 270         if (ret)
 271                 goto err;
 272
 273         ret = bch2_inode_unpack(k, inode);
 274         if (ret)
 275                 goto err;
 276
 277         return 0;
 278 err:
 279         bch2_trans_iter_exit(trans, iter);
 280         return ret;
 281 }
 282
 283 int bch2_inode_write(struct btree_trans *trans,
 284                      struct btree_iter *iter,
 285                      struct bch_inode_unpacked *inode)
 286 {
 287         struct bkey_inode_buf *inode_p;
 288
 289         inode_p = bch2_trans_kmalloc(trans, sizeof(*inode_p));
 290         if (IS_ERR(inode_p))
 291                 return PTR_ERR(inode_p);
 292
 293         bch2_inode_pack(trans->c, inode_p, inode);
 294         inode_p->inode.k.p.snapshot = iter->snapshot;
 295         return bch2_trans_update(trans, iter, &inode_p->inode.k_i, 0);
 296 }
 297
 298 const char *bch2_inode_invalid(const struct bch_fs *c, struct bkey_s_c k)
 299 {
 300         struct bkey_s_c_inode inode = bkey_s_c_to_inode(k);
 301         struct bch_inode_unpacked unpacked;
 302
 303         if (k.k->p.inode)
 304                 return "nonzero k.p.inode";
 305
 306         if (bkey_val_bytes(k.k) < sizeof(struct bch_inode))
 307                 return "incorrect value size";
 308
 309         if (k.k->p.offset < BLOCKDEV_INODE_MAX)
 310                 return "fs inode in blockdev range";
 311
 312         if (INODE_STR_HASH(inode.v) >= BCH_STR_HASH_NR)
 313                 return "invalid str hash type";
 314
 315         if (bch2_inode_unpack(k, &unpacked))
 316                 return "invalid variable length fields";
 317
 318         if (unpacked.bi_data_checksum >= BCH_CSUM_OPT_NR + 1)
 319                 return "invalid data checksum type";
 320
 321         if (unpacked.bi_compression >= BCH_COMPRESSION_OPT_NR + 1)
 322                 return "invalid data checksum type";
 323
 324         if ((unpacked.bi_flags & BCH_INODE_UNLINKED) &&
 325             unpacked.bi_nlink != 0)
 326                 return "flagged as unlinked but bi_nlink != 0";
 327
 328         if (unpacked.bi_subvol && !S_ISDIR(unpacked.bi_mode))
 329                 return "subvolume root but not a directory";
 330
 331         return NULL;
 332 }
 333
 334 const char *bch2_inode_v2_invalid(const struct bch_fs *c, struct bkey_s_c k)
 335 {
 336         struct bkey_s_c_inode_v2 inode = bkey_s_c_to_inode_v2(k);
 337         struct bch_inode_unpacked unpacked;
 338
 339         if (k.k->p.inode)
 340                 return "nonzero k.p.inode";
 341
 342         if (bkey_val_bytes(k.k) < sizeof(struct bch_inode))
 343                 return "incorrect value size";
 344
 345         if (k.k->p.offset < BLOCKDEV_INODE_MAX)
 346                 return "fs inode in blockdev range";
 347
 348         if (INODEv2_STR_HASH(inode.v) >= BCH_STR_HASH_NR)
 349                 return "invalid str hash type";
 350
 351         if (bch2_inode_unpack(k, &unpacked))
 352                 return "invalid variable length fields";
 353
 354         if (unpacked.bi_data_checksum >= BCH_CSUM_OPT_NR + 1)
 355                 return "invalid data checksum type";
 356
 357         if (unpacked.bi_compression >= BCH_COMPRESSION_OPT_NR + 1)
 358                 return "invalid data checksum type";
 359
 360         if ((unpacked.bi_flags & BCH_INODE_UNLINKED) &&
 361             unpacked.bi_nlink != 0)
 362                 return "flagged as unlinked but bi_nlink != 0";
 363
 364         if (unpacked.bi_subvol && !S_ISDIR(unpacked.bi_mode))
 365                 return "subvolume root but not a directory";
 366
 367         return NULL;
 368 }
 369
 370 static void __bch2_inode_unpacked_to_text(struct printbuf *out, struct bch_inode_unpacked *inode)
 371 {
 372         pr_buf(out, "mode %o flags %x journal_seq %llu",
 373                inode->bi_mode, inode->bi_flags,
 374                inode->bi_journal_seq);
 375
 376 #define x(_name, _bits)                                         \
 377         pr_buf(out, " "#_name " %llu", (u64) inode->_name);
 378         BCH_INODE_FIELDS()
 379 #undef  x
 380 }
 381
 382 void bch2_inode_unpacked_to_text(struct printbuf *out, struct bch_inode_unpacked *inode)
 383 {
 384         pr_buf(out, "inum: %llu ", inode->bi_inum);
 385         __bch2_inode_unpacked_to_text(out, inode);
 386 }
 387
 388 void bch2_inode_to_text(struct printbuf *out, struct bch_fs *c,
 389                        struct bkey_s_c k)
 390 {
 391         struct bch_inode_unpacked inode;
 392
 393         if (bch2_inode_unpack(k, &inode)) {
 394                 pr_buf(out, "(unpack error)");
 395                 return;
 396         }
 397
 398         __bch2_inode_unpacked_to_text(out, &inode);
 399 }
 400
 401 const char *bch2_inode_generation_invalid(const struct bch_fs *c,
 402                                           struct bkey_s_c k)
 403 {
 404         if (k.k->p.inode)
 405                 return "nonzero k.p.inode";
 406
 407         if (bkey_val_bytes(k.k) != sizeof(struct bch_inode_generation))
 408                 return "incorrect value size";
 409
 410         return NULL;
 411 }
 412
 413 void bch2_inode_generation_to_text(struct printbuf *out, struct bch_fs *c,
 414                                    struct bkey_s_c k)
 415 {
 416         struct bkey_s_c_inode_generation gen = bkey_s_c_to_inode_generation(k);
 417
 418         pr_buf(out, "generation: %u", le32_to_cpu(gen.v->bi_generation));
 419 }
 420
 421 void bch2_inode_init_early(struct bch_fs *c,
 422                            struct bch_inode_unpacked *inode_u)
 423 {
 424         enum bch_str_hash_type str_hash =
 425                 bch2_str_hash_opt_to_type(c, c->opts.str_hash);
 426
 427         memset(inode_u, 0, sizeof(*inode_u));
 428
 429         /* ick */
 430         inode_u->bi_flags |= str_hash << INODE_STR_HASH_OFFSET;
 431         get_random_bytes(&inode_u->bi_hash_seed,
 432                          sizeof(inode_u->bi_hash_seed));
 433 }
 434
 435 void bch2_inode_init_late(struct bch_inode_unpacked *inode_u, u64 now,
 436                           uid_t uid, gid_t gid, umode_t mode, dev_t rdev,
 437                           struct bch_inode_unpacked *parent)
 438 {
 439         inode_u->bi_mode        = mode;
 440         inode_u->bi_uid         = uid;
 441         inode_u->bi_gid         = gid;
 442         inode_u->bi_dev         = rdev;
 443         inode_u->bi_atime       = now;
 444         inode_u->bi_mtime       = now;
 445         inode_u->bi_ctime       = now;
 446         inode_u->bi_otime       = now;
 447
 448         if (parent && parent->bi_mode & S_ISGID) {
 449                 inode_u->bi_gid = parent->bi_gid;
 450                 if (S_ISDIR(mode))
 451                         inode_u->bi_mode |= S_ISGID;
 452         }
 453
 454         if (parent) {
 455 #define x(_name, ...)   inode_u->bi_##_name = parent->bi_##_name;
 456                 BCH_INODE_OPTS()
 457 #undef x
 458         }
 459 }
 460
 461 void bch2_inode_init(struct bch_fs *c, struct bch_inode_unpacked *inode_u,
 462                      uid_t uid, gid_t gid, umode_t mode, dev_t rdev,
 463                      struct bch_inode_unpacked *parent)
 464 {
 465         bch2_inode_init_early(c, inode_u);
 466         bch2_inode_init_late(inode_u, bch2_current_time(c),
 467                              uid, gid, mode, rdev, parent);
 468 }
 469
 470 static inline u32 bkey_generation(struct bkey_s_c k)
 471 {
 472         switch (k.k->type) {
 473         case KEY_TYPE_inode:
 474         case KEY_TYPE_inode_v2:
 475                 BUG();
 476         case KEY_TYPE_inode_generation:
 477                 return le32_to_cpu(bkey_s_c_to_inode_generation(k).v->bi_generation);
 478         default:
 479                 return 0;
 480         }
 481 }
 482
 483 /*
 484  * This just finds an empty slot:
 485  */
 486 int bch2_inode_create(struct btree_trans *trans,
 487                       struct btree_iter *iter,
 488                       struct bch_inode_unpacked *inode_u,
 489                       u32 snapshot, u64 cpu)
 490 {
 491         struct bch_fs *c = trans->c;
 492         struct bkey_s_c k;
 493         u64 min, max, start, pos, *hint;
 494         int ret = 0;
 495         unsigned bits = (c->opts.inodes_32bit ? 31 : 63);
 496
 497         if (c->opts.shard_inode_numbers) {
 498                 bits -= c->inode_shard_bits;
 499
 500                 min = (cpu << bits);
 501                 max = (cpu << bits) | ~(ULLONG_MAX << bits);
 502
 503                 min = max_t(u64, min, BLOCKDEV_INODE_MAX);
 504                 hint = c->unused_inode_hints + cpu;
 505         } else {
 506                 min = BLOCKDEV_INODE_MAX;
 507                 max = ~(ULLONG_MAX << bits);
 508                 hint = c->unused_inode_hints;
 509         }
 510
 511         start = READ_ONCE(*hint);
 512
 513         if (start >= max || start < min)
 514                 start = min;
 515
 516         pos = start;
 517         bch2_trans_iter_init(trans, iter, BTREE_ID_inodes, POS(0, pos),
 518                              BTREE_ITER_ALL_SNAPSHOTS|
 519                              BTREE_ITER_INTENT);
 520 again:
 521         while ((k = bch2_btree_iter_peek(iter)).k &&
 522                !(ret = bkey_err(k)) &&
 523                bkey_cmp(k.k->p, POS(0, max)) < 0) {
 524                 while (pos < iter->pos.offset) {
 525                         if (!bch2_btree_key_cache_find(c, BTREE_ID_inodes, POS(0, pos)))
 526                                 goto found_slot;
 527
 528                         pos++;
 529                 }
 530
 531                 if (k.k->p.snapshot == snapshot &&
 532                     !bkey_is_inode(k.k) &&
 533                     !bch2_btree_key_cache_find(c, BTREE_ID_inodes, SPOS(0, pos, snapshot))) {
 534                         bch2_btree_iter_advance(iter);
 535                         continue;
 536                 }
 537
 538                 /*
 539                  * We don't need to iterate over keys in every snapshot once
 540                  * we've found just one:
 541                  */
 542                 pos = iter->pos.offset + 1;
 543                 bch2_btree_iter_set_pos(iter, POS(0, pos));
 544         }
 545
 546         while (!ret && pos < max) {
 547                 if (!bch2_btree_key_cache_find(c, BTREE_ID_inodes, POS(0, pos)))
 548                         goto found_slot;
 549
 550                 pos++;
 551         }
 552
 553         if (!ret && start == min)
 554                 ret = -ENOSPC;
 555
 556         if (ret) {
 557                 bch2_trans_iter_exit(trans, iter);
 558                 return ret;
 559         }
 560
 561         /* Retry from start */
 562         pos = start = min;
 563         bch2_btree_iter_set_pos(iter, POS(0, pos));
 564         goto again;
 565 found_slot:
 566         bch2_btree_iter_set_pos(iter, SPOS(0, pos, snapshot));
 567         k = bch2_btree_iter_peek_slot(iter);
 568         ret = bkey_err(k);
 569         if (ret) {
 570                 bch2_trans_iter_exit(trans, iter);
 571                 return ret;
 572         }
 573
 574         /* We may have raced while the iterator wasn't pointing at pos: */
 575         if (bkey_is_inode(k.k) ||
 576             bch2_btree_key_cache_find(c, BTREE_ID_inodes, k.k->p))
 577                 goto again;
 578
 579         *hint                   = k.k->p.offset;
 580         inode_u->bi_inum        = k.k->p.offset;
 581         inode_u->bi_generation  = bkey_generation(k);
 582         return 0;
 583 }
 584
 585 static int bch2_inode_delete_keys(struct btree_trans *trans,
 586                                   subvol_inum inum, enum btree_id id)
 587 {
 588         struct btree_iter iter;
 589         struct bkey_s_c k;
 590         struct bkey_i delete;
 591         u32 snapshot;
 592         int ret = 0;
 593
 594         /*
 595          * We're never going to be deleting extents, no need to use an extent
 596          * iterator:
 597          */
 598         bch2_trans_iter_init(trans, &iter, id, POS(inum.inum, 0),
 599                              BTREE_ITER_NOT_EXTENTS|
 600                              BTREE_ITER_INTENT);
 601
 602         while (1) {
 603                 bch2_trans_begin(trans);
 604
 605                 ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
 606                 if (ret)
 607                         goto err;
 608
 609                 bch2_btree_iter_set_snapshot(&iter, snapshot);
 610
 611                 k = bch2_btree_iter_peek(&iter);
 612                 ret = bkey_err(k);
 613                 if (ret)
 614                         goto err;
 615
 616                 if (!k.k || iter.pos.inode != inum.inum)
 617                         break;
 618
 619                 bkey_init(&delete.k);
 620                 delete.k.p = iter.pos;
 621
 622                 ret = bch2_trans_update(trans, &iter, &delete, 0) ?:
 623                       bch2_trans_commit(trans, NULL, NULL,
 624                                         BTREE_INSERT_NOFAIL);
 625 err:
 626                 if (ret && ret != -EINTR)
 627                         break;
 628         }
 629
 630         bch2_trans_iter_exit(trans, &iter);
 631         return ret;
 632 }
 633
 634 int bch2_inode_rm(struct bch_fs *c, subvol_inum inum, bool cached)
 635 {
 636         struct btree_trans trans;
 637         struct btree_iter iter = { NULL };
 638         struct bkey_i_inode_generation delete;
 639         struct bch_inode_unpacked inode_u;
 640         struct bkey_s_c k;
 641         unsigned iter_flags = BTREE_ITER_INTENT;
 642         u32 snapshot;
 643         int ret;
 644
 645         if (0 && cached && c->opts.inodes_use_key_cache)
 646                 iter_flags |= BTREE_ITER_CACHED;
 647
 648         bch2_trans_init(&trans, c, 0, 1024);
 649
 650         /*
 651          * If this was a directory, there shouldn't be any real dirents left -
 652          * but there could be whiteouts (from hash collisions) that we should
 653          * delete:
 654          *
 655          * XXX: the dirent could ideally would delete whiteouts when they're no
 656          * longer needed
 657          */
 658         ret   = bch2_inode_delete_keys(&trans, inum, BTREE_ID_extents) ?:
 659                 bch2_inode_delete_keys(&trans, inum, BTREE_ID_xattrs) ?:
 660                 bch2_inode_delete_keys(&trans, inum, BTREE_ID_dirents);
 661         if (ret)
 662                 goto err;
 663 retry:
 664         bch2_trans_begin(&trans);
 665
 666         ret = bch2_subvolume_get_snapshot(&trans, inum.subvol, &snapshot);
 667         if (ret)
 668                 goto err;
 669
 670         bch2_trans_iter_init(&trans, &iter, BTREE_ID_inodes,
 671                              SPOS(0, inum.inum, snapshot), iter_flags);
 672         k = bch2_btree_iter_peek_slot(&iter);
 673
 674         ret = bkey_err(k);
 675         if (ret)
 676                 goto err;
 677
 678         if (!bkey_is_inode(k.k)) {
 679                 bch2_fs_inconsistent(trans.c,
 680                                      "inode %llu not found when deleting",
 681                                      inum.inum);
 682                 ret = -EIO;
 683                 goto err;
 684         }
 685
 686         bch2_inode_unpack(k, &inode_u);
 687
 688         /* Subvolume root? */
 689         BUG_ON(inode_u.bi_subvol);
 690
 691         bkey_inode_generation_init(&delete.k_i);
 692         delete.k.p = iter.pos;
 693         delete.v.bi_generation = cpu_to_le32(inode_u.bi_generation + 1);
 694
 695         ret   = bch2_trans_update(&trans, &iter, &delete.k_i, 0) ?:
 696                 bch2_trans_commit(&trans, NULL, NULL,
 697                                 BTREE_INSERT_NOFAIL);
 698 err:
 699         bch2_trans_iter_exit(&trans, &iter);
 700         if (ret == -EINTR)
 701                 goto retry;
 702
 703         bch2_trans_exit(&trans);
 704         return ret;
 705 }
 706
 707 int bch2_inode_find_by_inum_trans(struct btree_trans *trans,
 708                                   subvol_inum inum,
 709                                   struct bch_inode_unpacked *inode)
 710 {
 711         struct btree_iter iter;
 712         int ret;
 713
 714         ret = bch2_inode_peek(trans, &iter, inode, inum, 0);
 715         if (!ret)
 716                 bch2_trans_iter_exit(trans, &iter);
 717         return ret;
 718 }
 719
 720 int bch2_inode_find_by_inum(struct bch_fs *c, subvol_inum inum,
 721                             struct bch_inode_unpacked *inode)
 722 {
 723         return bch2_trans_do(c, NULL, NULL, 0,
 724                 bch2_inode_find_by_inum_trans(&trans, inum, inode));
 725 }