One btree update might have terminated in a node update, and then while
it is in flight another btree update might free that original node.
This race has to be handled in btree_update_nodes_written() - we were
missing a READ_ONCE().
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
bch2_fs_fatal_err_on(ret && !bch2_journal_error(&c->journal), c,
"%s", bch2_err_str(ret));
err:
- if (as->b) {
-
- b = as->b;
+ /*
+ * We have to be careful because another thread might be getting ready
+ * to free as->b and calling btree_update_reparent() on us - we'll
+ * recheck under btree_update_lock below:
+ */
+ b = READ_ONCE(as->b);
+ if (b) {
btree_path_idx_t path_idx = get_unlocked_mut_path(trans,
as->btree_id, b->c.level, b->key.k.p);
struct btree_path *path = trans->paths + path_idx;