bcachefs: Fix bch2_trigger_alloc when upgrading from old versions

bch2_trigger_alloc was assuming that the new key would always be newly
created and thus always an alloc_v4 key, but - not when called from
btree_gc.

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

diff --git a/fs/bcachefs/alloc_background.c b/fs/bcachefs/alloc_background.c
index d9c5a92..0a8a1bc 100644 (file)
--- a/fs/bcachefs/alloc_background.c
+++ b/fs/bcachefs/alloc_background.c
@@ -829,7 +829,19 @@ int bch2_trigger_alloc(struct btree_trans *trans,
 
        struct bch_alloc_v4 old_a_convert;
        const struct bch_alloc_v4 *old_a = bch2_alloc_to_v4(old, &old_a_convert);
-       struct bch_alloc_v4 *new_a = bkey_s_to_alloc_v4(new).v;
+
+       struct bch_alloc_v4 *new_a;
+       if (likely(new.k->type == KEY_TYPE_alloc_v4)) {
+               new_a = bkey_s_to_alloc_v4(new).v;
+       } else {
+               BUG_ON(!(flags & BTREE_TRIGGER_gc));
+
+               struct bkey_i_alloc_v4 *new_ka = bch2_alloc_to_v4_mut_inlined(trans, new.s_c);
+               ret = PTR_ERR_OR_ZERO(new_ka);
+               if (unlikely(ret))
+                       goto err;
+               new_a = &new_ka->v;
+       }
 
        if (flags & BTREE_TRIGGER_transactional) {
                alloc_data_type_set(new_a, new_a->data_type);