bcachefs: Improve error message when alloc key doesn't match lru entry

Error messages should always print out the full key when available -
this gives us a starting point when looking through the journal to debug
what went wrong.

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

diff --git a/fs/bcachefs/alloc_background.c b/fs/bcachefs/alloc_background.c
index 17b147d15320230ca5c4a894232c5af6911b2d95..1e6283b55e3b85339197df57bfb715e99d24a776 100644 (file)
--- a/fs/bcachefs/alloc_background.c
+++ b/fs/bcachefs/alloc_background.c
@@ -1082,6 +1082,7 @@ static int invalidate_one_bucket(struct btree_trans *trans, struct bch_dev *ca)
        struct bkey_s_c k;
        struct bkey_i_alloc_v4 *a;
        u64 bucket, idx;
+       struct printbuf buf = PRINTBUF;
        int ret;
 
        bch2_trans_iter_init(trans, &lru_iter, BTREE_ID_lru,
@@ -1107,10 +1108,16 @@ static int invalidate_one_bucket(struct btree_trans *trans, struct bch_dev *ca)
        if (ret)
                goto out;
 
-       if (bch2_trans_inconsistent_on(idx != alloc_lru_idx(a->v), trans,
-                       "invalidating bucket with wrong lru idx (got %llu should be %llu",
-                       idx, alloc_lru_idx(a->v)))
+       if (idx != alloc_lru_idx(a->v)) {
+               pr_buf(&buf, "alloc key does not point back to lru entry when invalidating bucket:\n  ");
+
+               bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&a->k_i));
+               pr_buf(&buf, "\n  ");
+               bch2_bkey_val_to_text(&buf, c, k);
+               bch2_trans_inconsistent(trans, "%s", buf.buf);
+               ret = -EINVAL;
                goto out;
+       }
 
        SET_BCH_ALLOC_V4_NEED_INC_GEN(&a->v, false);
        a->v.gen++;
@@ -1125,6 +1132,7 @@ static int invalidate_one_bucket(struct btree_trans *trans, struct bch_dev *ca)
 out:
        bch2_trans_iter_exit(trans, &alloc_iter);
        bch2_trans_iter_exit(trans, &lru_iter);
+       printbuf_exit(&buf);
        return ret;
 }