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 Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser 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"
33 #include "dev-setup.h"
41 #include "path-util.h"
47 typedef struct MountPoint {
56 /* The first three entries we might need before SELinux is up. The
57 * fourth (securityfs) is needed by IMA to load a custom policy. The
58 * other ones we can delay until SELinux and IMA are loaded. */
59 #define N_EARLY_MOUNT 4
61 static const MountPoint mount_table[] = {
62 { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
63 { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
64 { "devtmpfs", "/dev", "devtmpfs", "mode=755", MS_NOSUID|MS_STRICTATIME, true },
65 { "securityfs", "/sys/kernel/security", "securityfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, false },
66 { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME, true },
67 { "devpts", "/dev/pts", "devpts", "mode=620,gid=" STRINGIFY(TTY_GID), MS_NOSUID|MS_NOEXEC, false },
68 { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME, true },
69 { "tmpfs", "/sys/fs/cgroup", "tmpfs", "mode=755", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, false },
70 { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd", MS_NOSUID|MS_NOEXEC|MS_NODEV, false },
73 /* These are API file systems that might be mounted by other software,
74 * we just list them here so that we know that we should ignore them */
76 static const char ignore_paths[] =
77 /* SELinux file systems */
80 /* Legacy cgroup mount points */
83 /* Legacy kernel file system */
85 /* Container bind mounts */
93 bool mount_point_is_api(const char *path) {
96 /* Checks if this mount point is considered "API", and hence
97 * should be ignored */
99 for (i = 0; i < ELEMENTSOF(mount_table); i ++)
100 if (path_equal(path, mount_table[i].where))
103 return path_startswith(path, "/sys/fs/cgroup/");
106 bool mount_point_ignore(const char *path) {
109 NULSTR_FOREACH(i, ignore_paths)
110 if (path_equal(path, i))
116 static int mount_one(const MountPoint *p, bool relabel) {
121 /* Relabel first, just in case */
123 label_fix(p->where, true);
125 if ((r = path_is_mount_point(p->where, true)) < 0)
131 /* The access mode here doesn't really matter too much, since
132 * the mounted file system will take precedence anyway. */
133 mkdir_p(p->where, 0755);
135 log_debug("Mounting %s to %s of type %s with options %s.",
146 log_full(p->fatal ? LOG_ERR : LOG_DEBUG, "Failed to mount %s: %s", p->where, strerror(errno));
147 return p->fatal ? -errno : 0;
150 /* Relabel again, since we now mounted something fresh here */
152 label_fix(p->where, false);
157 int mount_setup_early(void) {
161 assert_cc(N_EARLY_MOUNT <= ELEMENTSOF(mount_table));
163 /* Do a minimal mount of /proc and friends to enable the most
164 * basic stuff, such as SELinux */
165 for (i = 0; i < N_EARLY_MOUNT; i ++) {
168 j = mount_one(mount_table + i, false);
176 int mount_cgroup_controllers(char ***join_controllers) {
182 /* Mount all available cgroup controllers that are built into the kernel. */
184 f = fopen("/proc/cgroups", "re");
186 log_error("Failed to enumerate cgroup controllers: %m");
190 controllers = set_new(string_hash_func, string_compare_func);
193 log_error("Failed to allocate controller set.");
197 /* Ignore the header line */
198 (void) fgets(buf, sizeof(buf), f);
204 if (fscanf(f, "%ms %*i %*i %i", &controller, &enabled) != 2) {
209 log_error("Failed to parse /proc/cgroups.");
219 r = set_put(controllers, controller);
221 log_error("Failed to add controller to set.");
229 char *controller, *where, *options;
232 controller = set_steal_first(controllers);
236 if (join_controllers)
237 for (k = join_controllers; *k; k++)
238 if (strv_find(*k, controller))
244 for (i = *k, j = *k; *i; i++) {
246 if (!streq(*i, controller)) {
249 t = set_remove(controllers, *i);
262 options = strv_join(*k, ",");
264 log_error("Failed to join options");
271 options = controller;
275 where = strappend("/sys/fs/cgroup/", options);
277 log_error("Failed to build path");
288 p.flags = MS_NOSUID|MS_NOEXEC|MS_NODEV;
291 r = mount_one(&p, true);
300 if (r > 0 && k && *k) {
303 for (i = *k; *i; i++) {
306 t = strappend("/sys/fs/cgroup/", *i);
308 log_error("Failed to build path");
314 r = symlink(options, t);
317 if (r < 0 && errno != EEXIST) {
318 log_error("Failed to create symlink: %m");
332 set_free_free(controllers);
341 const struct stat *sb,
343 struct FTW *ftwbuf) {
345 /* No need to label /dev twice in a row... */
346 if (_unlikely_(ftwbuf->level == 0))
349 label_fix(fpath, true);
351 /* /run/initramfs is static data and big, no need to
352 * dynamically relabel its contents at boot... */
353 if (_unlikely_(ftwbuf->level == 1 &&
355 streq(fpath, "/run/initramfs")))
356 return FTW_SKIP_SUBTREE;
361 int mount_setup(bool loaded_policy) {
363 static const char relabel[] =
364 "/run/initramfs/root-fsck\0"
365 "/run/initramfs/shutdown\0";
371 for (i = 0; i < ELEMENTSOF(mount_table); i ++) {
372 r = mount_one(mount_table + i, true);
378 /* Nodes in devtmpfs and /run need to be manually updated for
379 * the appropriate labels, after mounting. The other virtual
380 * API file systems like /sys and /proc do not need that, they
381 * use the same label for all their files. */
383 usec_t before_relabel, after_relabel;
384 char timespan[FORMAT_TIMESPAN_MAX];
386 before_relabel = now(CLOCK_MONOTONIC);
388 nftw("/dev", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL);
389 nftw("/run", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL);
391 /* Explicitly relabel these */
392 NULSTR_FOREACH(j, relabel)
395 after_relabel = now(CLOCK_MONOTONIC);
397 log_info("Relabelled /dev and /run in %s.",
398 format_timespan(timespan, sizeof(timespan), after_relabel - before_relabel));
401 /* Create a few default symlinks, which are normally created
402 * by udevd, but some scripts might need them before we start
406 /* Create a few directories we always want around */
407 label_mkdir("/run/systemd", 0755);
408 label_mkdir("/run/systemd/system", 0755);