+ /*
+ * Not a fsck error because this is checked/repaired by
+ * bch2_check_alloc_key() which runs later:
+ */
+ if (!bch2_dev_bucket_exists(c, k.k->p))
+ continue;
+
+ ca = bch_dev_bkey_exists(c, k.k->p.inode);
+
+ *bucket_gen(ca, k.k->p.offset) = bch2_alloc_to_v4(k, &a)->gen;
+ }
+ bch2_trans_iter_exit(&trans, &iter);
+
+ bch2_trans_exit(&trans);
+
+ if (ret)
+ bch_err(c, "error reading alloc info: %s", bch2_err_str(ret));
+
+ return ret;
+}
+
+static struct bpos alloc_gens_pos(struct bpos pos, unsigned *offset)
+{
+ *offset = pos.offset & KEY_TYPE_BUCKET_GENS_MASK;
+
+ pos.offset >>= KEY_TYPE_BUCKET_GENS_BITS;
+ return pos;
+}
+
+static struct bpos bucket_gens_pos_to_alloc(struct bpos pos, unsigned offset)
+{
+ pos.offset <<= KEY_TYPE_BUCKET_GENS_BITS;
+ pos.offset += offset;
+ return pos;
+}
+
+static unsigned alloc_gen(struct bkey_s_c k, unsigned offset)
+{
+ return k.k->type == KEY_TYPE_bucket_gens
+ ? bkey_s_c_to_bucket_gens(k).v->gens[offset]
+ : 0;
+}
+
+int bch2_bucket_gens_invalid(const struct bch_fs *c, struct bkey_s_c k,
+ unsigned flags, struct printbuf *err)
+{
+ if (bkey_val_bytes(k.k) != sizeof(struct bch_bucket_gens)) {
+ prt_printf(err, "bad val size (%lu != %zu)",
+ bkey_val_bytes(k.k), sizeof(struct bch_bucket_gens));
+ return -BCH_ERR_invalid_bkey;
+ }
+
+ return 0;
+}
+
+void bch2_bucket_gens_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k)
+{
+ struct bkey_s_c_bucket_gens g = bkey_s_c_to_bucket_gens(k);
+ unsigned i;
+
+ for (i = 0; i < ARRAY_SIZE(g.v->gens); i++) {
+ if (i)
+ prt_char(out, ' ');
+ prt_printf(out, "%u", g.v->gens[i]);
+ }
+}
+
+int bch2_bucket_gens_init(struct bch_fs *c)
+{
+ struct btree_trans trans;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct bch_alloc_v4 a;
+ struct bkey_i_bucket_gens g;
+ bool have_bucket_gens_key = false;
+ unsigned offset;
+ struct bpos pos;
+ u8 gen;
+ int ret;
+
+ bch2_trans_init(&trans, c, 0, 0);
+
+ for_each_btree_key(&trans, iter, BTREE_ID_alloc, POS_MIN,
+ BTREE_ITER_PREFETCH, k, ret) {
+ /*
+ * Not a fsck error because this is checked/repaired by
+ * bch2_check_alloc_key() which runs later:
+ */
+ if (!bch2_dev_bucket_exists(c, k.k->p))
+ continue;
+
+ gen = bch2_alloc_to_v4(k, &a)->gen;
+ pos = alloc_gens_pos(iter.pos, &offset);
+
+ if (have_bucket_gens_key && bkey_cmp(iter.pos, pos)) {
+ ret = commit_do(&trans, NULL, NULL,
+ BTREE_INSERT_NOFAIL|
+ BTREE_INSERT_LAZY_RW,
+ __bch2_btree_insert(&trans, BTREE_ID_bucket_gens, &g.k_i, 0));
+ if (ret)
+ break;
+ have_bucket_gens_key = false;
+ }
+
+ if (!have_bucket_gens_key) {
+ bkey_bucket_gens_init(&g.k_i);
+ g.k.p = pos;
+ have_bucket_gens_key = true;
+ }
+
+ g.v.gens[offset] = gen;
+ }
+ bch2_trans_iter_exit(&trans, &iter);
+
+ if (have_bucket_gens_key && !ret)
+ ret = commit_do(&trans, NULL, NULL,
+ BTREE_INSERT_NOFAIL|
+ BTREE_INSERT_LAZY_RW,
+ __bch2_btree_insert(&trans, BTREE_ID_bucket_gens, &g.k_i, 0));
+
+ bch2_trans_exit(&trans);
+
+ if (ret)
+ bch_err(c, "%s: error %s", __func__, bch2_err_str(ret));
+
+ return ret;
+}
+
+int bch2_bucket_gens_read(struct bch_fs *c)
+{
+ struct btree_trans trans;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ const struct bch_bucket_gens *g;
+ struct bch_dev *ca;
+ u64 b;
+ int ret;
+
+ bch2_trans_init(&trans, c, 0, 0);
+
+ for_each_btree_key(&trans, iter, BTREE_ID_bucket_gens, POS_MIN,
+ BTREE_ITER_PREFETCH, k, ret) {
+ u64 start = bucket_gens_pos_to_alloc(k.k->p, 0).offset;
+ u64 end = bucket_gens_pos_to_alloc(bpos_nosnap_successor(k.k->p), 0).offset;
+
+ if (k.k->type != KEY_TYPE_bucket_gens)
+ continue;
+
+ g = bkey_s_c_to_bucket_gens(k).v;
+
+ /*
+ * Not a fsck error because this is checked/repaired by
+ * bch2_check_alloc_key() which runs later:
+ */
+ if (!bch2_dev_exists2(c, k.k->p.inode))
+ continue;
+