bcachefs: better backpointer_target_not_found() error message

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

diff --git a/fs/bcachefs/backpointers.c b/fs/bcachefs/backpointers.c
index 5cc4aaa3a3255c13067409fdfa169ca955ff08ca..b93ddfa00fddeabd397f3797204d5d48860ce14e 100644 (file)
--- a/fs/bcachefs/backpointers.c
+++ b/fs/bcachefs/backpointers.c
@@ -210,10 +210,21 @@ static int backpointer_target_not_found(struct btree_trans *trans,
        prt_printf(&buf, "backpointer doesn't match %s it points to:\n  ",
                   bp.v->level ? "btree node" : "extent");
        bch2_bkey_val_to_text(&buf, c, bp.s_c);
-       prt_printf(&buf, "\n  ");
 
+       prt_printf(&buf, "\n  ");
        bch2_bkey_val_to_text(&buf, c, target_k);
 
+       struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(target_k);
+       const union bch_extent_entry *entry;
+       struct extent_ptr_decoded p;
+       bkey_for_each_ptr_decode(target_k.k, ptrs, p, entry)
+               if (p.ptr.dev == bp.k->p.inode) {
+                       prt_printf(&buf, "\n  ");
+                       struct bkey_i_backpointer bp2;
+                       bch2_extent_ptr_to_bp(c, bp.v->btree_id, bp.v->level, target_k, p, entry, &bp2);
+                       bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&bp2.k_i));
+               }
+
        if (fsck_err(trans, backpointer_to_missing_ptr,
                     "%s", buf.buf))
                ret = bch2_backpointer_del(trans, bp.k->p);