util-lib: move open_serialization_fd() to serialize.c

It definitely fits better there.

No code changes, just some rearranging.

src/basic/fileio.c

@@ -9,7 +9,6 @@
 #include <stdio_ext.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/mman.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -25,7 +24,6 @@
 #include "missing.h"
 #include "parse-util.h"
 #include "path-util.h"
-#include "process-util.h"
 #include "stdio-util.h"
 #include "string-util.h"
 #include "strv.h"
@@ -1219,25 +1217,6 @@ int fputs_with_space(FILE *f, const char *s, const char *separator, bool *space)
         return fputs(s, f);
 }
 
-int open_serialization_fd(const char *ident) {
-        int fd;
-
-        fd = memfd_create(ident, MFD_CLOEXEC);
-        if (fd < 0) {
-                const char *path;
-
-                path = getpid_cached() == 1 ? "/run/systemd" : "/tmp";
-                fd = open_tmpfile_unlinkable(path, O_RDWR|O_CLOEXEC);
-                if (fd < 0)
-                        return fd;
-
-                log_debug("Serializing %s to %s.", ident, path);
-        } else
-                log_debug("Serializing %s to memfd.", ident);
-
-        return fd;
-}
-
 int read_nul_string(FILE *f, char **ret) {
         _cleanup_free_ char *x = NULL;
         size_t allocated = 0, n = 0;

src/basic/fileio.h

@@ -71,8 +71,6 @@ int read_timestamp_file(const char *fn, usec_t *ret);
 
 int fputs_with_space(FILE *f, const char *s, const char *separator, bool *space);
 
-int open_serialization_fd(const char *ident);
-
 int read_nul_string(FILE *f, char **ret);
 
 int read_line(FILE *f, size_t limit, char **ret);

src/shared/serialize.c

@@ -1,12 +1,16 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
 
+#include <sys/mman.h>
+
 #include "alloc-util.h"
 #include "env-util.h"
 #include "escape.h"
 #include "fileio.h"
 #include "parse-util.h"
+#include "process-util.h"
 #include "serialize.h"
 #include "strv.h"
+#include "tmpfile-util.h"
 
 int serialize_item(FILE *f, const char *key, const char *value) {
         assert(f);
@@ -188,3 +192,22 @@ int deserialize_environment(const char *value, char ***list) {
         unescaped = NULL; /* now part of 'list' */
         return 0;
 }
+
+int open_serialization_fd(const char *ident) {
+        int fd;
+
+        fd = memfd_create(ident, MFD_CLOEXEC);
+        if (fd < 0) {
+                const char *path;
+
+                path = getpid_cached() == 1 ? "/run/systemd" : "/tmp";
+                fd = open_tmpfile_unlinkable(path, O_RDWR|O_CLOEXEC);
+                if (fd < 0)
+                        return fd;
+
+                log_debug("Serializing %s to %s.", ident, path);
+        } else
+                log_debug("Serializing %s to memfd.", ident);
+
+        return fd;
+}

src/shared/serialize.h

@@ -21,3 +21,5 @@ static inline int serialize_bool(FILE *f, const char *key, bool b) {
 int deserialize_usec(const char *value, usec_t *timestamp);
 int deserialize_dual_timestamp(const char *value, dual_timestamp *t);
 int deserialize_environment(const char *value, char ***environment);
+
+int open_serialization_fd(const char *ident);

src/test/test-fd-util.c

@@ -10,6 +10,7 @@
 #include "path-util.h"
 #include "process-util.h"
 #include "random-util.h"
+#include "serialize.h"
 #include "string-util.h"
 #include "tests.h"
 #include "tmpfile-util.h"