Prep v239: Uncomment header inclusions that are new or needed now.

[elogind.git] / src / basic / fd-util.c

diff --git a/src/basic/fd-util.c b/src/basic/fd-util.c
index ed82cd6283cf4463b86d5c19cdb3f253fcc5e2bb..1efd83b7f6a899259c98dc16f3b73b3b3fb45ac1 100644 (file)
--- a/src/basic/fd-util.c
+++ b/src/basic/fd-util.c
@@ -1,9 +1,4 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
-/***
-  This file is part of systemd.
-
-  Copyright 2010 Lennart Poettering
-***/
 
 #include <errno.h>
 #include <fcntl.h>
@@ -12,8 +7,8 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
-//#include "alloc-util.h"
-//#include "copy.h"
+#include "alloc-util.h"
+#include "copy.h"
 #include "dirent-util.h"
 #include "fd-util.h"
 #include "fileio.h"
@@ -934,3 +929,27 @@ int fd_reopen(int fd, int flags) {
 
         return new_fd;
 }
+
+int read_nr_open(void) {
+        _cleanup_free_ char *nr_open = NULL;
+        int r;
+
+        /* Returns the kernel's current fd limit, either by reading it of /proc/sys if that works, or using the
+         * hard-coded default compiled-in value of current kernels (1M) if not. This call will never fail. */
+
+        r = read_one_line_file("/proc/sys/fs/nr_open", &nr_open);
+        if (r < 0)
+                log_debug_errno(r, "Failed to read /proc/sys/fs/nr_open, ignoring: %m");
+        else {
+                int v;
+
+                r = safe_atoi(nr_open, &v);
+                if (r < 0)
+                        log_debug_errno(r, "Failed to parse /proc/sys/fs/nr_open value '%s', ignoring: %m", nr_open);
+                else
+                        return v;
+        }
+
+        /* If we fail, fallback to the hard-coded kernel limit of 1024 * 1024. */
+        return 1024 * 1024;
+}