bcachefs: Plumb more logging through stdio redirect

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

fs/bcachefs/bcachefs.h

@@ -267,6 +267,8 @@ do {									\
 
 #define bch2_fmt(_c, fmt)		bch2_log_msg(_c, fmt "\n")
 
+void bch2_print_str(struct bch_fs *, const char *);
+
 __printf(2, 3)
 void bch2_print_opts(struct bch_opts *, const char *, ...);
 

fs/bcachefs/btree_iter.c

@@ -1465,7 +1465,7 @@ void bch2_dump_trans_updates(struct btree_trans *trans)
 	struct printbuf buf = PRINTBUF;
 
 	bch2_trans_updates_to_text(&buf, trans);
-	bch2_print_string_as_lines(KERN_ERR, buf.buf);
+	bch2_print_str(trans->c, buf.buf);
 	printbuf_exit(&buf);
 }
 
@@ -1557,7 +1557,7 @@ void __bch2_dump_trans_paths_updates(struct btree_trans *trans, bool nosort)
 	__bch2_trans_paths_to_text(&buf, trans, nosort);
 	bch2_trans_updates_to_text(&buf, trans);
 
-	bch2_print_string_as_lines(KERN_ERR, buf.buf);
+	bch2_print_str(trans->c, buf.buf);
 	printbuf_exit(&buf);
 }
 

fs/bcachefs/super.c

@@ -89,6 +89,19 @@ const char * const bch2_fs_flag_strs[] = {
 	NULL
 };
 
+void bch2_print_str(struct bch_fs *c, const char *str)
+{
+#ifdef __KERNEL__
+	struct stdio_redirect *stdio = bch2_fs_stdio_redirect(c);
+
+	if (unlikely(stdio)) {
+		bch2_stdio_redirect_printf(stdio, true, "%s", str);
+		return;
+	}
+#endif
+	bch2_print_string_as_lines(KERN_ERR, str);
+}
+
 __printf(2, 0)
 static void bch2_print_maybe_redirect(struct stdio_redirect *stdio, const char *fmt, va_list args)
 {