machine-id: fix missing initialization

src/core/machine-id-setup.c

@@ -151,7 +151,8 @@ static int generate(char id[34]) {
 }
 
 int machine_id_setup(void) {
-        int fd, r;
+        _cleanup_close_ int fd = -1;
+        int r;
         bool writable;
         struct stat st;
         char id[34]; /* 32 + \n + \0 */
@@ -178,31 +179,25 @@ int machine_id_setup(void) {
 
         if (fstat(fd, &st) < 0) {
                 log_error("fstat() failed: %m");
-                r = -errno;
-                goto finish;
+                return -errno;
         }
 
-        if (S_ISREG(st.st_mode)) {
-                if (loop_read(fd, id, 32, false) >= 32) {
-                        r = 0;
-                        goto finish;
-                }
-        }
+        if (S_ISREG(st.st_mode))
+                if (loop_read(fd, id, 32, false) >= 32)
+                        return 0;
 
         /* Hmm, so, the id currently stored is not useful, then let's
          * generate one */
 
         r = generate(id);
         if (r < 0)
-                goto finish;
+                return r;
 
         if (S_ISREG(st.st_mode) && writable) {
                 lseek(fd, 0, SEEK_SET);
 
-                if (loop_write(fd, id, 33, false) == 33) {
-                        r = 0;
-                        goto finish;
-                }
+                if (loop_write(fd, id, 33, false) == 33)
+                        return 0;
         }
 
         close_nointr_nofail(fd);
@@ -216,29 +211,23 @@ int machine_id_setup(void) {
         }
         if (r < 0) {
                 log_error("Cannot write /run/machine-id: %s", strerror(-r));
-
                 unlink("/run/machine-id");
-                goto finish;
+                return r;
         }
 
         /* And now, let's mount it over */
-        r = mount("/run/machine-id", "/etc/machine-id", NULL, MS_BIND, NULL) < 0 ? -errno : 0;
+        r = mount("/run/machine-id", "/etc/machine-id", NULL, MS_BIND, NULL);
         if (r < 0) {
-                unlink("/run/machine-id");
-                log_error("Failed to mount /etc/machine-id: %s", strerror(-r));
-        } else {
-                log_info("Installed transient /etc/machine-id file.");
-
-                /* Mark the mount read-only */
-                if (mount(NULL, "/etc/machine-id", NULL,
-                          MS_BIND|MS_RDONLY|MS_REMOUNT, NULL) < 0)
-                        log_warning("Failed to make transient /etc/machine-id read-only");
+                log_error("Failed to mount /etc/machine-id: %m");
+                unlink_noerrno("/run/machine-id");
+                return -errno;
         }
 
-finish:
+        log_info("Installed transient /etc/machine-id file.");
 
-        if (fd >= 0)
-                close_nointr_nofail(fd);
+        /* Mark the mount read-only */
+        if (mount(NULL, "/etc/machine-id", NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, NULL) < 0)
+                log_warning("Failed to make transient /etc/machine-id read-only: %m");
 
-        return r;
+        return 0;
 }

src/shared/util.c

@@ -234,6 +234,17 @@ void close_many(const int fds[], unsigned n_fd) {
                 close_nointr_nofail(fds[i]);
 }
 
+int unlink_noerrno(const char *path) {
+        PROTECT_ERRNO;
+        int r;
+
+        r = unlink(path);
+        if (r < 0)
+                return -errno;
+
+        return 0;
+}
+
 int parse_boolean(const char *v) {
         assert(v);
 

src/shared/util.h

@@ -646,3 +646,5 @@ static inline unsigned u64log2(uint64_t n) {
 static inline bool logind_running(void) {
         return access("/run/systemd/seats/", F_OK) >= 0;
 }
+
+int unlink_noerrno(const char *path);