From af229d7a5be768a49a7f0d1028d878a71b797bad Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Fri, 16 Feb 2018 06:58:33 +0100
Subject: [PATCH] login,user-sessions: always warn when we fail to remove
 nologin file

This usually is very annoying to users who then cannot log in, so
make sure we always warn if that happens (selinux, or whatever other reason).

This reverts a790812cb349c5cef95d1b4a20fc80ca08d3a145.
---
 src/basic/fs-util.c               | 11 +++++++++++
 src/basic/fs-util.h               |  2 ++
 src/login/logind-dbus.c           |  2 +-
 src/login/logind.c                |  3 ++-
 src/user-sessions/user-sessions.c | 26 +++++---------------------
 5 files changed, 21 insertions(+), 23 deletions(-)

diff --git a/src/basic/fs-util.c b/src/basic/fs-util.c
index c96c7d0d25..47edcbb04f 100644
--- a/src/basic/fs-util.c
+++ b/src/basic/fs-util.c
@@ -554,6 +554,17 @@ int tmp_dir(const char **ret) {
         return tmp_dir_internal("/tmp", ret);
 }
 
+int unlink_or_warn(const char *filename) {
+        if (unlink(filename) < 0 && errno != ENOENT)
+                /* If the file doesn't exist and the fs simply was read-only (in which
+                 * case unlink() returns EROFS even if the file doesn't exist), don't
+                 * complain */
+                if (errno != EROFS || access(filename, F_OK) >= 0)
+                        return log_error_errno(errno, "Failed to remove \"%s\": %m", filename);
+
+        return 0;
+}
+
 int inotify_add_watch_fd(int fd, int what, uint32_t mask) {
         char path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int) + 1];
         int r;
diff --git a/src/basic/fs-util.h b/src/basic/fs-util.h
index ae40d6d37f..acb83dfd83 100644
--- a/src/basic/fs-util.h
+++ b/src/basic/fs-util.h
@@ -64,6 +64,8 @@ int get_files_in_directory(const char *path, char ***list);
 int tmp_dir(const char **ret);
 int var_tmp_dir(const char **ret);
 
+int unlink_or_warn(const char *filename);
+
 #define INOTIFY_EVENT_MAX (sizeof(struct inotify_event) + NAME_MAX + 1)
 
 #define FOREACH_INOTIFY_EVENT(e, buffer, sz) \
diff --git a/src/login/logind-dbus.c b/src/login/logind-dbus.c
index ed9eba1ee0..aa4bbf7739 100644
--- a/src/login/logind-dbus.c
+++ b/src/login/logind-dbus.c
@@ -2010,7 +2010,7 @@ static void reset_scheduled_shutdown(Manager *m) {
         m->shutdown_dry_run = false;
 
         if (m->unlink_nologin) {
-                (void) unlink("/run/nologin");
+                (void) unlink_or_warn("/run/nologin");
                 m->unlink_nologin = false;
         }
 
diff --git a/src/login/logind.c b/src/login/logind.c
index d9b5f026cf..0a869ba447 100644
--- a/src/login/logind.c
+++ b/src/login/logind.c
@@ -35,6 +35,7 @@
 #include "dirent-util.h"
 #include "fd-util.h"
 #include "format-util.h"
+#include "fs-util.h"
 #include "logind.h"
 #include "process-util.h"
 #include "selinux-util.h"
@@ -183,7 +184,7 @@ static void manager_free(Manager *m) {
         udev_unref(m->udev);
 
         if (m->unlink_nologin)
-                (void) unlink("/run/nologin");
+                (void) unlink_or_warn("/run/nologin");
 
         bus_verify_polkit_async_registry_free(m->polkit_registry);
 
diff --git a/src/user-sessions/user-sessions.c b/src/user-sessions/user-sessions.c
index 795766a657..1aed9adae7 100644
--- a/src/user-sessions/user-sessions.c
+++ b/src/user-sessions/user-sessions.c
@@ -23,12 +23,14 @@
 
 #include "fileio.h"
 #include "fileio-label.h"
+#include "fs-util.h"
 #include "log.h"
 #include "selinux-util.h"
 #include "string-util.h"
 #include "util.h"
 
 int main(int argc, char*argv[]) {
+        int r, k;
 
         if (argc != 2) {
                 log_error("This program requires one argument.");
@@ -44,30 +46,12 @@ int main(int argc, char*argv[]) {
         mac_selinux_init();
 
         if (streq(argv[1], "start")) {
-                int r = 0;
-
-                if (unlink("/run/nologin") < 0 && errno != ENOENT)
-                        r = log_error_errno(errno,
-                                            "Failed to remove /run/nologin file: %m");
-
-                if (unlink("/etc/nologin") < 0 && errno != ENOENT) {
-                        /* If the file doesn't exist and /etc simply
-                         * was read-only (in which case unlink()
-                         * returns EROFS even if the file doesn't
-                         * exist), don't complain */
-
-                        if (errno != EROFS || access("/etc/nologin", F_OK) >= 0) {
-                                log_error_errno(errno, "Failed to remove /etc/nologin file: %m");
-                                return EXIT_FAILURE;
-                        }
-                }
-
-                if (r < 0)
+                r = unlink_or_warn("/run/nologin");
+                k = unlink_or_warn("/etc/nologin");
+                if (r < 0 || k < 0)
                         return EXIT_FAILURE;
 
         } else if (streq(argv[1], "stop")) {
-                int r;
-
                 r = write_string_file_atomic_label("/run/nologin", "System is going down.");
                 if (r < 0) {
                         log_error_errno(r, "Failed to create /run/nologin: %m");