Merge pull request #26944 from aafeijoo-suse/systemd-network-generator-initrd-fix

network-generator: do not parse kernel command line more than once

4 files changed, 80 insertions, 33 deletions

diff --git a/src/basic/fs-util.c b/src/basic/fs-util.c
index f8cd93800d..1e1413dc80 100644
--- a/src/basic/fs-util.c
+++ b/src/basic/fs-util.c
@@ -820,7 +820,7 @@ int conservative_renameat(
         _cleanup_close_ int old_fd = -EBADF, new_fd = -EBADF;
         struct stat old_stat, new_stat;
 
-        /* Renames the old path to thew new path, much like renameat() — except if both are regular files and
+        /* Renames the old path to the new path, much like renameat() — except if both are regular files and
          * have the exact same contents and basic file attributes already. In that case remove the new file
          * instead. This call is useful for reducing inotify wakeups on files that are updated but don't
          * actually change. This function is written in a style that we rather rename too often than suppress
diff --git a/src/network/generator/main.c b/src/network/generator/main.c
index a0af0b831b..492980249b 100644
--- a/src/network/generator/main.c
+++ b/src/network/generator/main.c
@@ -4,6 +4,7 @@
 
 #include "build.h"
 #include "fd-util.h"
+#include "fs-util.h"
 #include "generator.h"
 #include "macro.h"
 #include "main-func.h"
@@ -17,67 +18,97 @@
 static const char *arg_root = NULL;
 
 static int network_save(Network *network, const char *dest_dir) {
-        _cleanup_free_ char *filename = NULL;
+        _cleanup_free_ char *filename = NULL, *p = NULL;
+        _cleanup_(unlink_and_freep) char *temp_path = NULL;
         _cleanup_fclose_ FILE *f = NULL;
         int r;
 
         assert(network);
 
+        r = generator_open_unit_file_full(dest_dir, NULL, NULL, &f, &temp_path);
+        if (r < 0)
+                return r;
+
+        network_dump(network, f);
+
         r = asprintf(&filename, "%s-%s.network",
                      isempty(network->ifname) ? "91" : "90",
                      isempty(network->ifname) ? "default" : network->ifname);
         if (r < 0)
                 return log_oom();
 
-        r = generator_open_unit_file(dest_dir, "kernel command line", filename, &f);
+        p = path_join(dest_dir, filename);
+        if (!p)
+                return log_oom();
+
+        r = conservative_rename(temp_path, p);
         if (r < 0)
                 return r;
 
-        network_dump(network, f);
-
+        temp_path = mfree(temp_path);
         return 0;
 }
 
 static int netdev_save(NetDev *netdev, const char *dest_dir) {
-        _cleanup_free_ char *filename = NULL;
+        _cleanup_free_ char *filename = NULL, *p = NULL;
+        _cleanup_(unlink_and_freep) char *temp_path = NULL;
         _cleanup_fclose_ FILE *f = NULL;
         int r;
 
         assert(netdev);
 
+        r = generator_open_unit_file_full(dest_dir, NULL, NULL, &f, &temp_path);
+        if (r < 0)
+                return r;
+
+        netdev_dump(netdev, f);
+
         r = asprintf(&filename, "90-%s.netdev",
                      netdev->ifname);
         if (r < 0)
                 return log_oom();
 
-        r = generator_open_unit_file(dest_dir, "kernel command line", filename, &f);
+        p = path_join(dest_dir, filename);
+        if (!p)
+                return log_oom();
+
+        r = conservative_rename(temp_path, p);
         if (r < 0)
                 return r;
 
-        netdev_dump(netdev, f);
-
+        temp_path = mfree(temp_path);
         return 0;
 }
 
 static int link_save(Link *link, const char *dest_dir) {
-        _cleanup_free_ char *filename = NULL;
+        _cleanup_free_ char *filename = NULL, *p = NULL;
+        _cleanup_(unlink_and_freep) char *temp_path = NULL;
         _cleanup_fclose_ FILE *f = NULL;
         int r;
 
         assert(link);
 
+        r = generator_open_unit_file_full(dest_dir, NULL, NULL, &f, &temp_path);
+        if (r < 0)
+                return r;
+
+        link_dump(link, f);
+
         filename = strjoin(!isempty(link->ifname) ? "90" :
                            !hw_addr_is_null(&link->mac) ? "91" : "92",
                            "-", link->filename, ".link");
         if (!filename)
                 return log_oom();
 
-        r = generator_open_unit_file(dest_dir, "kernel command line", filename, &f);
+        p = path_join(dest_dir, filename);
+        if (!p)
+                return log_oom();
+
+        r = conservative_rename(temp_path, p);
         if (r < 0)
                 return r;
 
-        link_dump(link, f);
-
+        temp_path = mfree(temp_path);
         return 0;
 }
 
diff --git a/src/shared/generator.c b/src/shared/generator.c
index 2ed4be2bf3..b16d0a0ef2 100644
--- a/src/shared/generator.c
+++ b/src/shared/generator.c
@@ -21,41 +21,57 @@
 #include "specifier.h"
 #include "string-util.h"
 #include "time-util.h"
+#include "tmpfile-util.h"
 #include "unit-name.h"
 
-int generator_open_unit_file(
+int generator_open_unit_file_full(
                 const char *dir,
                 const char *source,
                 const char *fn,
-                FILE **ret) {
+                FILE **ret_file,
+                char **ret_temp_path) {
 
         _cleanup_free_ char *p = NULL;
         FILE *f;
         int r;
 
         assert(dir);
-        assert(fn);
-        assert(ret);
+        assert(ret_file);
 
-        p = path_join(dir, fn);
-        if (!p)
-                return log_oom();
+        /* If <ret_temp_path> is specified, it creates a temporary unit file and also returns its
+         * temporary path. */
 
-        r = fopen_unlocked(p, "wxe", &f);
-        if (r < 0) {
-                if (source && r == -EEXIST)
-                        return log_error_errno(r,
-                                               "Failed to create unit file '%s', as it already exists. Duplicate entry in '%s'?",
-                                               p, source);
+        if (ret_temp_path) {
+                r = fopen_temporary(dir, &f, &p);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to create temporary unit file in '%s': %m", dir);
+
+                (void) fchmod(fileno(f), 0644);
 
-                return log_error_errno(r, "Failed to create unit file '%s': %m", p);
+                *ret_temp_path = TAKE_PTR(p);
+        } else {
+                assert(fn);
+
+                p = path_join(dir, fn);
+                if (!p)
+                        return log_oom();
+
+                r = fopen_unlocked(p, "wxe", &f);
+                if (r < 0) {
+                        if (source && r == -EEXIST)
+                                return log_error_errno(r,
+                                                       "Failed to create unit file '%s', as it already exists. Duplicate entry in '%s'?",
+                                                       p, source);
+
+                        return log_error_errno(r, "Failed to create unit file '%s': %m", p);
+                }
         }
 
         fprintf(f,
                 "# Automatically generated by %s\n\n",
                 program_invocation_short_name);
 
-        *ret = f;
+        *ret_file = f;
         return 0;
 }
 
diff --git a/src/shared/generator.h b/src/shared/generator.h
index 111900fd45..d97d6edc67 100644
--- a/src/shared/generator.h
+++ b/src/shared/generator.h
@@ -6,11 +6,11 @@
 #include "macro.h"
 #include "main-func.h"
 
-int generator_open_unit_file(
-        const char *dest,
-        const char *source,
-        const char *name,
-        FILE **file);
+int generator_open_unit_file_full(const char *dest, const char *source, const char *name, FILE **ret_file, char **ret_temp_path);
+
+static inline int generator_open_unit_file(const char *dest, const char *source, const char *name, FILE **ret_file) {
+        return generator_open_unit_file_full(dest, source, name, ret_file, NULL);
+}
 
 int generator_add_symlink_full(const char *dir, const char *dst, const char *dep_type, const char *src, const char *instance);