bcachefs: Fix reading of alloc info after unclean shutdown

When updates to interior nodes started being journalled, that meant that
after an unclean shutdown, until journal replay is done we can't walk
the btree without overlaying the updates from the journal.

The initial btree gc was changed to walk the btree overlaying keys from
the journal - but bch2_alloc_read() and bch2_stripes_read() were missed.
Major whoops...

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 72 insertions, 0 deletions

diff --git a/fs/bcachefs/recovery.c b/fs/bcachefs/recovery.c
index 8e9d412a6000..95265f1c2b21 100644
--- a/fs/bcachefs/recovery.c
+++ b/fs/bcachefs/recovery.c
@@ -191,6 +191,78 @@ void bch2_btree_and_journal_iter_init_node_iter(struct btree_and_journal_iter *i
 			       b->c.btree_id, b->c.level, b->data->min_key);
 }
 
+/* Walk btree, overlaying keys from the journal: */
+
+static int bch2_btree_and_journal_walk_recurse(struct bch_fs *c, struct btree *b,
+				struct journal_keys *journal_keys,
+				enum btree_id btree_id,
+				btree_walk_node_fn node_fn,
+				btree_walk_key_fn key_fn)
+{
+	struct btree_and_journal_iter iter;
+	struct bkey_s_c k;
+	int ret = 0;
+
+	bch2_btree_and_journal_iter_init_node_iter(&iter, journal_keys, b);
+
+	while ((k = bch2_btree_and_journal_iter_peek(&iter)).k) {
+		ret = key_fn(c, btree_id, b->c.level, k);
+		if (ret)
+			break;
+
+		if (b->c.level) {
+			struct btree *child;
+			BKEY_PADDED(k) tmp;
+
+			bkey_reassemble(&tmp.k, k);
+			k = bkey_i_to_s_c(&tmp.k);
+
+			bch2_btree_and_journal_iter_advance(&iter);
+
+			if (b->c.level > 0) {
+				child = bch2_btree_node_get_noiter(c, &tmp.k,
+							b->c.btree_id, b->c.level - 1);
+				ret = PTR_ERR_OR_ZERO(child);
+				if (ret)
+					break;
+
+				ret   = (node_fn ? node_fn(c, b) : 0) ?:
+					bch2_btree_and_journal_walk_recurse(c, child,
+						journal_keys, btree_id, node_fn, key_fn);
+				six_unlock_read(&child->c.lock);
+
+				if (ret)
+					break;
+			}
+		} else {
+			bch2_btree_and_journal_iter_advance(&iter);
+		}
+	}
+
+	return ret;
+}
+
+int bch2_btree_and_journal_walk(struct bch_fs *c, struct journal_keys *journal_keys,
+				enum btree_id btree_id,
+				btree_walk_node_fn node_fn,
+				btree_walk_key_fn key_fn)
+{
+	struct btree *b = c->btree_roots[btree_id].b;
+	int ret = 0;
+
+	if (btree_node_fake(b))
+		return 0;
+
+	six_lock_read(&b->c.lock, NULL, NULL);
+	ret   = (node_fn ? node_fn(c, b) : 0) ?:
+		bch2_btree_and_journal_walk_recurse(c, b, journal_keys, btree_id,
+						    node_fn, key_fn) ?:
+		key_fn(c, btree_id, b->c.level + 1, bkey_i_to_s_c(&b->key));
+	six_unlock_read(&b->c.lock);
+
+	return ret;
+}
+
 /* sort and dedup all keys in the journal: */
 
 void bch2_journal_entries_free(struct list_head *list)