Isolation of udev code from remaining systemd

This commit is a first attempt to isolate the udev code from the
remaining code base.  It intentionally does not modify any files
but purely delete files which, on a first examination, appear to
not be needed.  This is a sweeping commit which may easily have
missed needed code.  Files can be retrieved by doing a checkout
from the previous commit:

 git checkout 2944f347d0 -- <filename>

1 files changed, 0 insertions, 142 deletions

diff --git a/src/core/switch-root.c b/src/core/switch-root.c
deleted file mode 100644
index 150332a858..0000000000
--- a/src/core/switch-root.c
+++ /dev/null
@@ -1,142 +0,0 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
-  This file is part of systemd.
-
-  Copyright 2012 Harald Hoyer, Lennart Poettering
-
-  systemd is free software; you can redistribute it and/or modify it
-  under the terms of the GNU Lesser General Public License as published by
-  the Free Software Foundation; either version 2.1 of the License, or
-  (at your option) any later version.
-
-  systemd is distributed in the hope that it will be useful, but
-  WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public License
-  along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <sys/stat.h>
-#include <stdbool.h>
-#include <errno.h>
-#include <string.h>
-#include <sys/mount.h>
-#include <unistd.h>
-#include <fcntl.h>
-
-#include "util.h"
-#include "path-util.h"
-#include "switch-root.h"
-
-int switch_root(const char *new_root) {
-
-        /*  Don't try to unmount/move the old "/", there's no way to do it. */
-        static const char move_mounts[] =
-                "/dev\0"
-                "/proc\0"
-                "/sys\0"
-                "/run\0";
-
-        int r, old_root_fd = -1;
-        struct stat new_root_stat;
-        bool old_root_remove;
-        const char *i;
-
-        if (path_equal(new_root, "/"))
-                return 0;
-
-        old_root_remove = in_initrd();
-
-        if (stat(new_root, &new_root_stat) < 0) {
-                r = -errno;
-                log_error("Failed to stat directory %s: %m", new_root);
-                goto fail;
-        }
-
-        /* Work-around for a kernel bug: for some reason the kernel
-         * refuses switching root if any file systems are mounted
-         * MS_SHARED. Hence remount them MS_PRIVATE here as a
-         * work-around.
-         *
-         * https://bugzilla.redhat.com/show_bug.cgi?id=847418 */
-        if (mount(NULL, "/", NULL, MS_REC|MS_PRIVATE, NULL) < 0)
-                log_warning("Failed to make \"/\" private mount: %m");
-
-        NULSTR_FOREACH(i, move_mounts) {
-                char new_mount[PATH_MAX];
-                struct stat sb;
-
-                snprintf(new_mount, sizeof(new_mount), "%s%s", new_root, i);
-                char_array_0(new_mount);
-
-                if ((stat(new_mount, &sb) < 0) ||
-                    sb.st_dev != new_root_stat.st_dev) {
-
-                        /* Mount point seems to be mounted already or
-                         * stat failed. Unmount the old mount
-                         * point. */
-                        if (umount2(i, MNT_DETACH) < 0)
-                                log_warning("Failed to unmount %s: %m", i);
-                        continue;
-                }
-
-                if (mount(i, new_mount, NULL, MS_MOVE, NULL) < 0) {
-                        log_error("Failed to move mount %s to %s, forcing unmount: %m", i, new_mount);
-
-                        if (umount2(i, MNT_FORCE) < 0)
-                                log_warning("Failed to unmount %s: %m", i);
-                }
-        }
-
-        if (chdir(new_root) < 0) {
-                r = -errno;
-                log_error("Failed to change directory to %s: %m", new_root);
-                goto fail;
-        }
-
-        if (old_root_remove) {
-                old_root_fd = open("/", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_NOCTTY|O_DIRECTORY);
-                if (old_root_fd < 0)
-                        log_warning("Failed to open root directory: %m");
-        }
-
-        if (mount(new_root, "/", NULL, MS_MOVE, NULL) < 0) {
-                r = -errno;
-                log_error("Failed to mount moving %s to /: %m", new_root);
-                goto fail;
-        }
-
-        if (chroot(".") < 0) {
-                r = -errno;
-                log_error("Failed to change root: %m");
-                goto fail;
-        }
-
-        if (chdir("/") < 0) {
-                r = -errno;
-                log_error("Failed to change directory: %m");
-                goto fail;
-        }
-
-        if (old_root_fd >= 0) {
-                struct stat rb;
-
-                if (fstat(old_root_fd, &rb) < 0)
-                        log_warning("Failed to stat old root directory, leaving: %m");
-                else {
-                        rm_rf_children(old_root_fd, false, false, &rb);
-                        old_root_fd = -1;
-                }
-        }
-
-        r = 0;
-
-fail:
-        if (old_root_fd >= 0)
-                close_nointr_nofail(old_root_fd);
-
-        return r;
-}