1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2010 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
22 #include <sys/mount.h>
32 #include "mount-setup.h"
42 typedef struct MountPoint {
51 /* The first three entries we might need before SELinux is up. The
52 * other ones we can delay until SELinux is loaded. */
53 #define N_EARLY_MOUNT 3
55 static const MountPoint mount_table[] = {
56 { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
57 { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
58 { "devtmpfs", "/dev", "devtmpfs", "mode=755", MS_NOSUID, true },
59 { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV, true },
60 { "devpts", "/dev/pts", "devpts", "mode=620,gid=" STRINGIFY(TTY_GID), MS_NOSUID|MS_NOEXEC, false },
61 { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV, true },
62 { "tmpfs", "/sys/fs/cgroup", "tmpfs", "mode=755", MS_NOSUID|MS_NOEXEC|MS_NODEV, false },
63 { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd", MS_NOSUID|MS_NOEXEC|MS_NODEV, false },
66 /* These are API file systems that might be mounted by other software,
67 * we just list them here so that we know that we should ignore them */
69 static const char * const ignore_paths[] = {
75 bool mount_point_is_api(const char *path) {
78 /* Checks if this mount point is considered "API", and hence
79 * should be ignored */
81 for (i = 0; i < ELEMENTSOF(mount_table); i ++)
82 if (path_equal(path, mount_table[i].where))
85 return path_startswith(path, "/sys/fs/cgroup/");
88 bool mount_point_ignore(const char *path) {
91 for (i = 0; i < ELEMENTSOF(ignore_paths); i++)
92 if (path_equal(path, ignore_paths[i]))
98 static int mount_one(const MountPoint *p, bool relabel) {
103 /* Relabel first, just in case */
105 label_fix(p->where, true);
107 if ((r = path_is_mount_point(p->where)) < 0)
113 /* The access mode here doesn't really matter too much, since
114 * the mounted file system will take precedence anyway. */
115 mkdir_p(p->where, 0755);
117 log_debug("Mounting %s to %s of type %s with options %s.",
128 log_error("Failed to mount %s: %s", p->where, strerror(errno));
129 return p->fatal ? -errno : 0;
132 /* Relabel again, since we now mounted something fresh here */
134 label_fix(p->where, false);
139 int mount_setup_early(void) {
143 assert_cc(N_EARLY_MOUNT <= ELEMENTSOF(mount_table));
145 /* Do a minimal mount of /proc and friends to enable the most
146 * basic stuff, such as SELinux */
147 for (i = 0; i < N_EARLY_MOUNT; i ++) {
150 j = mount_one(mount_table + i, false);
158 static int mount_cgroup_controllers(void) {
163 /* Mount all available cgroup controllers that are built into the kernel. */
165 if (!(f = fopen("/proc/cgroups", "re"))) {
166 log_error("Failed to enumerate cgroup controllers: %m");
170 /* Ignore the header line */
171 (void) fgets(buf, sizeof(buf), f);
175 char *controller, *where;
178 if (fscanf(f, "%ms %*i %*i %i", &controller, &enabled) != 2) {
183 log_error("Failed to parse /proc/cgroups.");
193 if (asprintf(&where, "/sys/fs/cgroup/%s", controller) < 0) {
203 p.options = controller;
204 p.flags = MS_NOSUID|MS_NOEXEC|MS_NODEV;
207 r = mount_one(&p, true);
223 static int symlink_and_label(const char *old_path, const char *new_path) {
229 if ((r = label_symlinkfile_set(new_path)) < 0)
232 if (symlink(old_path, new_path) < 0)
242 const struct stat *sb,
244 struct FTW *ftwbuf) {
246 /* No need to label /dev twice in a row... */
247 if (ftwbuf->level == 0)
250 label_fix(fpath, true);
254 int mount_setup(bool loaded_policy) {
256 const char symlinks[] =
257 "/proc/kcore\0" "/dev/core\0"
258 "/proc/self/fd\0" "/dev/fd\0"
259 "/proc/self/fd/0\0" "/dev/stdin\0"
260 "/proc/self/fd/1\0" "/dev/stdout\0"
261 "/proc/self/fd/2\0" "/dev/stderr\0";
267 for (i = 0; i < ELEMENTSOF(mount_table); i ++) {
268 r = mount_one(mount_table + i, true);
274 /* Nodes in devtmpfs and /run need to be manually updated for
275 * the appropriate labels, after mounting. The other virtual
276 * API file systems like /sys and /proc do not need that, they
277 * use the same label for all their files. */
279 usec_t before_relabel, after_relabel;
280 char timespan[FORMAT_TIMESPAN_MAX];
282 before_relabel = now(CLOCK_MONOTONIC);
284 nftw("/dev", nftw_cb, 64, FTW_MOUNT|FTW_PHYS);
285 nftw("/run", nftw_cb, 64, FTW_MOUNT|FTW_PHYS);
287 after_relabel = now(CLOCK_MONOTONIC);
289 log_info("Relabelled /dev and /run in %s.",
290 format_timespan(timespan, sizeof(timespan), after_relabel - before_relabel));
294 /* Create a few default symlinks, which are normally created
295 * by udevd, but some scripts might need them before we start
297 NULSTR_FOREACH_PAIR(j, k, symlinks)
298 symlink_and_label(j, k);
300 /* Create a few directories we always want around */
301 mkdir("/run/systemd", 0755);
302 mkdir("/run/systemd/system", 0755);
304 return mount_cgroup_controllers();