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"
48 typedef struct MountPoint {
57 /* The first three entries we might need before SELinux is up. The
58 * fourth (securityfs) is needed by IMA to load a custom policy. The
59 * other ones we can delay until SELinux and IMA are loaded. */
60 #define N_EARLY_MOUNT 4
62 static const MountPoint mount_table[] = {
63 { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
64 { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
65 { "devtmpfs", "/dev", "devtmpfs", "mode=755", MS_NOSUID|MS_STRICTATIME, true },
66 { "securityfs", "/sys/kernel/security", "securityfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, false },
67 { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME, true },
68 { "devpts", "/dev/pts", "devpts", "mode=620,gid=" STRINGIFY(TTY_GID), MS_NOSUID|MS_NOEXEC, false },
69 { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME, true },
70 { "tmpfs", "/sys/fs/cgroup", "tmpfs", "mode=755", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, false },
71 { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd", MS_NOSUID|MS_NOEXEC|MS_NODEV, false },
74 /* These are API file systems that might be mounted by other software,
75 * we just list them here so that we know that we should ignore them */
77 static const char ignore_paths[] =
78 /* SELinux file systems */
81 /* Legacy cgroup mount points */
84 /* Legacy kernel file system */
86 /* Container bind mounts */
94 bool mount_point_is_api(const char *path) {
97 /* Checks if this mount point is considered "API", and hence
98 * should be ignored */
100 for (i = 0; i < ELEMENTSOF(mount_table); i ++)
101 if (path_equal(path, mount_table[i].where))
104 return path_startswith(path, "/sys/fs/cgroup/");
107 bool mount_point_ignore(const char *path) {
110 NULSTR_FOREACH(i, ignore_paths)
111 if (path_equal(path, i))
117 static int mount_one(const MountPoint *p, bool relabel) {
122 /* Relabel first, just in case */
124 label_fix(p->where, true, true);
126 if ((r = path_is_mount_point(p->where, true)) < 0)
132 /* The access mode here doesn't really matter too much, since
133 * the mounted file system will take precedence anyway. */
134 mkdir_p_label(p->where, 0755);
136 log_debug("Mounting %s to %s of type %s with options %s.",
147 log_full(p->fatal ? LOG_ERR : LOG_DEBUG, "Failed to mount %s: %s", p->where, strerror(errno));
148 return p->fatal ? -errno : 0;
151 /* Relabel again, since we now mounted something fresh here */
153 label_fix(p->where, false, false);
158 int mount_setup_early(void) {
162 assert_cc(N_EARLY_MOUNT <= ELEMENTSOF(mount_table));
164 /* Do a minimal mount of /proc and friends to enable the most
165 * basic stuff, such as SELinux */
166 for (i = 0; i < N_EARLY_MOUNT; i ++) {
169 j = mount_one(mount_table + i, false);
177 int mount_cgroup_controllers(char ***join_controllers) {
183 /* Mount all available cgroup controllers that are built into the kernel. */
185 f = fopen("/proc/cgroups", "re");
187 log_error("Failed to enumerate cgroup controllers: %m");
191 controllers = set_new(string_hash_func, string_compare_func);
194 log_error("Failed to allocate controller set.");
198 /* Ignore the header line */
199 (void) fgets(buf, sizeof(buf), f);
205 if (fscanf(f, "%ms %*i %*i %i", &controller, &enabled) != 2) {
210 log_error("Failed to parse /proc/cgroups.");
220 r = set_put(controllers, controller);
222 log_error("Failed to add controller to set.");
230 char *controller, *where, *options;
233 controller = set_steal_first(controllers);
237 if (join_controllers)
238 for (k = join_controllers; *k; k++)
239 if (strv_find(*k, controller))
245 for (i = *k, j = *k; *i; i++) {
247 if (!streq(*i, controller)) {
250 t = set_remove(controllers, *i);
263 options = strv_join(*k, ",");
265 log_error("Failed to join options");
272 options = controller;
276 where = strappend("/sys/fs/cgroup/", options);
278 log_error("Failed to build path");
289 p.flags = MS_NOSUID|MS_NOEXEC|MS_NODEV;
292 r = mount_one(&p, true);
301 if (r > 0 && k && *k) {
304 for (i = *k; *i; i++) {
307 t = strappend("/sys/fs/cgroup/", *i);
309 log_error("Failed to build path");
315 r = symlink(options, t);
318 if (r < 0 && errno != EEXIST) {
319 log_error("Failed to create symlink: %m");
333 set_free_free(controllers);
342 const struct stat *sb,
344 struct FTW *ftwbuf) {
346 /* No need to label /dev twice in a row... */
347 if (_unlikely_(ftwbuf->level == 0))
350 label_fix(fpath, false, false);
352 /* /run/initramfs is static data and big, no need to
353 * dynamically relabel its contents at boot... */
354 if (_unlikely_(ftwbuf->level == 1 &&
356 streq(fpath, "/run/initramfs")))
357 return FTW_SKIP_SUBTREE;
362 int mount_setup(bool loaded_policy) {
364 static const char relabel[] =
365 "/run/initramfs/root-fsck\0"
366 "/run/initramfs/shutdown\0";
372 for (i = 0; i < ELEMENTSOF(mount_table); i ++) {
373 r = mount_one(mount_table + i, true);
379 /* Nodes in devtmpfs and /run need to be manually updated for
380 * the appropriate labels, after mounting. The other virtual
381 * API file systems like /sys and /proc do not need that, they
382 * use the same label for all their files. */
384 usec_t before_relabel, after_relabel;
385 char timespan[FORMAT_TIMESPAN_MAX];
387 before_relabel = now(CLOCK_MONOTONIC);
389 nftw("/dev", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL);
390 nftw("/run", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL);
392 /* Explicitly relabel these */
393 NULSTR_FOREACH(j, relabel)
394 label_fix(j, true, false);
396 after_relabel = now(CLOCK_MONOTONIC);
398 log_info("Relabelled /dev and /run in %s.",
399 format_timespan(timespan, sizeof(timespan), after_relabel - before_relabel));
402 /* Create a few default symlinks, which are normally created
403 * by udevd, but some scripts might need them before we start
407 /* Create a few directories we always want around */
408 mkdir_label("/run/systemd", 0755);
409 mkdir_label("/run/systemd/system", 0755);