bcachefs: Increment restart count in bch2_trans_begin()

Instead of counting transaction restarts, count when the transaction is
restarted: if bch2_trans_begin() was called when the transaction wasn't
restarted we need to ensure restart_count is still incremented.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

fs/bcachefs/btree_iter.c

@@ -3229,6 +3229,7 @@ u32 bch2_trans_begin(struct btree_trans *trans)
 
 	bch2_trans_reset_updates(trans);
 
+	trans->restart_count++;
 	trans->mem_top			= 0;
 
 	if (trans->fs_usage_deltas) {

fs/bcachefs/btree_iter.h

@@ -218,7 +218,6 @@ static inline int btree_trans_restart_nounlock(struct btree_trans *trans, int er
 	BUG_ON(!bch2_err_matches(err, BCH_ERR_transaction_restart));
 
 	trans->restarted = err;
-	trans->restart_count++;
 	return -err;
 }
 

fs/bcachefs/fsck.c

@@ -1149,13 +1149,11 @@ static int check_i_sectors(struct btree_trans *trans, struct inode_walker *w)
 		}
 	}
 fsck_err:
-	if (ret) {
+	if (ret)
 		bch_err(c, "error from check_i_sectors(): %s", bch2_err_str(ret));
-		return ret;
-	}
-	if (trans_was_restarted(trans, restart_count))
-		return -BCH_ERR_transaction_restart_nested;
-	return 0;
+	if (!ret && trans_was_restarted(trans, restart_count))
+		ret = -BCH_ERR_transaction_restart_nested;
+	return ret;
 }
 
 static int check_extent(struct btree_trans *trans, struct btree_iter *iter,