X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fsystem-update-generator%2Fsystem-update-generator.c;h=464ee22b208b66ff9e20e305163aad4e9f089a9a;hb=d920e59c7df63300e5b5191d2a4be7b3baac6ea8;hp=0cfccfb494bc3a96a4d4544cc2ade813ab408b66;hpb=d360705f0f1262d49cccb6507abeafb7cfb5bbe0;p=elogind.git

diff --git a/src/system-update-generator/system-update-generator.c b/src/system-update-generator/system-update-generator.c
index 0cfccfb49..464ee22b2 100644
--- a/src/system-update-generator/system-update-generator.c
+++ b/src/system-update-generator/system-update-generator.c
@@ -27,33 +27,27 @@
 #include "unit-name.h"
 #include "path-util.h"
 
+/*
+ * Implements the logic described in
+ * http://freedesktop.org/wiki/Software/systemd/SystemUpdates
+ */
+
 static const char *arg_dest = "/tmp";
 
 static int generate_symlink(void) {
-        struct stat st;
-        char *p;
+        const char *p = NULL;
 
-        if (lstat("/system-update", &st) < 0) {
+        if (access("/system-update", F_OK) < 0) {
                 if (errno == ENOENT)
                         return 0;
 
-                log_error("Failed to check for system update: %m");
+                log_error_errno(errno, "Failed to check for system update: %m");
                 return -EINVAL;
         }
 
-        p = strappend(arg_dest, "/default.target");
-        if (!p) {
-                log_error("Out of memory.");
-                return -ENOMEM;
-        }
-
-        if (symlink(SYSTEM_DATA_UNIT_PATH "/system-update.target", p) < 0) {
-                free(p);
-                log_error("Failed to create symlink: %m");
-                return -errno;
-        }
-
-        free(p);
+        p = strappenda(arg_dest, "/default.target");
+        if (symlink(SYSTEM_DATA_UNIT_PATH "/system-update.target", p) < 0)
+                return log_error_errno(errno, "Failed to create symlink %s: %m", p);
 
         return 0;
 }
@@ -61,15 +55,15 @@ static int generate_symlink(void) {
 int main(int argc, char *argv[]) {
         int r;
 
-        if (argc > 2) {
-                log_error("This program takes one or no arguments.");
+        if (argc > 1 && argc != 4) {
+                log_error("This program takes three or no arguments.");
                 return EXIT_FAILURE;
         }
 
         if (argc > 1)
-                arg_dest = argv[1];
+                arg_dest = argv[2];
 
-        log_set_target(LOG_TARGET_AUTO);
+        log_set_target(LOG_TARGET_SAFE);
         log_parse_environment();
         log_open();