+
+void __bch2_bkey_compat(unsigned level, enum btree_id btree_id,
+ unsigned version, unsigned big_endian,
+ int write,
+ struct bkey_format *f,
+ struct bkey_packed *k)
+{
+ const struct bkey_ops *ops;
+ struct bkey uk;
+ unsigned nr_compat = 5;
+ int i;
+
+ /*
+ * Do these operations in reverse order in the write path:
+ */
+
+ for (i = 0; i < nr_compat; i++)
+ switch (!write ? i : nr_compat - 1 - i) {
+ case 0:
+ if (big_endian != CPU_BIG_ENDIAN)
+ bch2_bkey_swab_key(f, k);
+ break;
+ case 1:
+ if (version < bcachefs_metadata_version_bkey_renumber)
+ bch2_bkey_renumber(__btree_node_type(level, btree_id), k, write);
+ break;
+ case 2:
+ if (version < bcachefs_metadata_version_inode_btree_change &&
+ btree_id == BTREE_ID_inodes) {
+ if (!bkey_packed(k)) {
+ struct bkey_i *u = packed_to_bkey(k);
+
+ swap(u->k.p.inode, u->k.p.offset);
+ } else if (f->bits_per_field[BKEY_FIELD_INODE] &&
+ f->bits_per_field[BKEY_FIELD_OFFSET]) {
+ struct bkey_format tmp = *f, *in = f, *out = &tmp;
+
+ swap(tmp.bits_per_field[BKEY_FIELD_INODE],
+ tmp.bits_per_field[BKEY_FIELD_OFFSET]);
+ swap(tmp.field_offset[BKEY_FIELD_INODE],
+ tmp.field_offset[BKEY_FIELD_OFFSET]);
+
+ if (!write)
+ swap(in, out);
+
+ uk = __bch2_bkey_unpack_key(in, k);
+ swap(uk.p.inode, uk.p.offset);
+ BUG_ON(!bch2_bkey_pack_key(k, &uk, out));
+ }
+ }
+ break;
+ case 3:
+ if (version < bcachefs_metadata_version_snapshot &&
+ (level || btree_type_has_snapshots(btree_id))) {
+ struct bkey_i *u = packed_to_bkey(k);
+
+ if (u) {
+ u->k.p.snapshot = write
+ ? 0 : U32_MAX;
+ } else {
+ u64 min_packed = le64_to_cpu(f->field_offset[BKEY_FIELD_SNAPSHOT]);
+ u64 max_packed = min_packed +
+ ~(~0ULL << f->bits_per_field[BKEY_FIELD_SNAPSHOT]);
+
+ uk = __bch2_bkey_unpack_key(f, k);
+ uk.p.snapshot = write
+ ? min_packed : min_t(u64, U32_MAX, max_packed);
+
+ BUG_ON(!bch2_bkey_pack_key(k, &uk, f));
+ }
+ }
+
+ break;
+ case 4: {
+ struct bkey_s u;
+
+ if (!bkey_packed(k)) {
+ u = bkey_i_to_s(packed_to_bkey(k));
+ } else {
+ uk = __bch2_bkey_unpack_key(f, k);
+ u.k = &uk;
+ u.v = bkeyp_val(f, k);
+ }
+
+ if (big_endian != CPU_BIG_ENDIAN)
+ bch2_bkey_swab_val(u);
+
+ ops = bch2_bkey_type_ops(k->type);
+
+ if (ops->compat)
+ ops->compat(btree_id, version, big_endian, write, u);
+ break;
+ }
+ default:
+ BUG();
+ }
+}