chiark / gitweb /
dev-setup: allow a path prefix for use in chroots
[elogind.git] / src / core / mount-setup.c
index 52fe523..be11bb8 100644 (file)
@@ -30,6 +30,7 @@
 #include <ftw.h>
 
 #include "mount-setup.h"
+#include "dev-setup.h"
 #include "log.h"
 #include "macro.h"
 #include "util.h"
@@ -37,6 +38,8 @@
 #include "set.h"
 #include "strv.h"
 #include "mkdir.h"
+#include "path-util.h"
+#include "missing.h"
 
 #ifndef TTY_GID
 #define TTY_GID 5
@@ -71,11 +74,22 @@ static const MountPoint mount_table[] = {
 /* These are API file systems that might be mounted by other software,
  * we just list them here so that we know that we should ignore them */
 
-static const char * const ignore_paths[] = {
-        "/sys/fs/selinux",
-        "/selinux",
-        "/proc/bus/usb"
-};
+static const char ignore_paths[] =
+        /* SELinux file systems */
+        "/sys/fs/selinux\0"
+        "/selinux\0"
+        /* Legacy cgroup mount points */
+        "/dev/cgroup\0"
+        "/cgroup\0"
+        /* Legacy kernel file system */
+        "/proc/bus/usb\0"
+        /* Container bind mounts */
+        "/proc/sys\0"
+        "/dev/console\0"
+        "/proc/kmsg\0"
+        "/etc/localtime\0"
+        "/etc/timezone\0"
+        "/etc/machine-id\0";
 
 bool mount_point_is_api(const char *path) {
         unsigned i;
@@ -91,10 +105,10 @@ bool mount_point_is_api(const char *path) {
 }
 
 bool mount_point_ignore(const char *path) {
-        unsigned i;
+        const char *i;
 
-        for (i = 0; i < ELEMENTSOF(ignore_paths); i++)
-                if (path_equal(path, ignore_paths[i]))
+        NULSTR_FOREACH(i, ignore_paths)
+                if (path_equal(path, i))
                         return true;
 
         return false;
@@ -107,7 +121,7 @@ static int mount_one(const MountPoint *p, bool relabel) {
 
         /* Relabel first, just in case */
         if (relabel)
-                label_fix(p->where, true);
+                label_fix(p->where, true, true);
 
         if ((r = path_is_mount_point(p->where, true)) < 0)
                 return r;
@@ -117,7 +131,7 @@ static int mount_one(const MountPoint *p, bool relabel) {
 
         /* The access mode here doesn't really matter too much, since
          * the mounted file system will take precedence anyway. */
-        mkdir_p(p->where, 0755);
+        mkdir_p_label(p->where, 0755);
 
         log_debug("Mounting %s to %s of type %s with options %s.",
                   p->what,
@@ -130,13 +144,13 @@ static int mount_one(const MountPoint *p, bool relabel) {
                   p->type,
                   p->flags,
                   p->options) < 0) {
-                log_error("Failed to mount %s: %s", p->where, strerror(errno));
+                log_full(p->fatal ? LOG_ERR : LOG_DEBUG, "Failed to mount %s: %s", p->where, strerror(errno));
                 return p->fatal ? -errno : 0;
         }
 
         /* Relabel again, since we now mounted something fresh here */
         if (relabel)
-                label_fix(p->where, false);
+                label_fix(p->where, false, false);
 
         return 1;
 }
@@ -176,8 +190,7 @@ int mount_cgroup_controllers(char ***join_controllers) {
 
         controllers = set_new(string_hash_func, string_compare_func);
         if (!controllers) {
-                r = -ENOMEM;
-                log_error("Failed to allocate controller set.");
+                r = log_oom();
                 goto finish;
         }
 
@@ -248,9 +261,8 @@ int mount_cgroup_controllers(char ***join_controllers) {
 
                         options = strv_join(*k, ",");
                         if (!options) {
-                                log_error("Failed to join options");
                                 free(controller);
-                                r = -ENOMEM;
+                                r = log_oom();
                                 goto finish;
                         }
 
@@ -261,9 +273,8 @@ int mount_cgroup_controllers(char ***join_controllers) {
 
                 where = strappend("/sys/fs/cgroup/", options);
                 if (!where) {
-                        log_error("Failed to build path");
                         free(options);
-                        r = -ENOMEM;
+                        r = log_oom();
                         goto finish;
                 }
 
@@ -292,8 +303,7 @@ int mount_cgroup_controllers(char ***join_controllers) {
 
                                 t = strappend("/sys/fs/cgroup/", *i);
                                 if (!t) {
-                                        log_error("Failed to build path");
-                                        r = -ENOMEM;
+                                        r = log_oom();
                                         free(options);
                                         goto finish;
                                 }
@@ -323,23 +333,6 @@ finish:
         return r;
 }
 
-static int symlink_and_label(const char *old_path, const char *new_path) {
-        int r;
-
-        assert(old_path);
-        assert(new_path);
-
-        if ((r = label_symlinkfile_set(new_path)) < 0)
-                return r;
-
-        if (symlink(old_path, new_path) < 0)
-                r = -errno;
-
-        label_file_clear();
-
-        return r;
-}
-
 static int nftw_cb(
                 const char *fpath,
                 const struct stat *sb,
@@ -350,7 +343,7 @@ static int nftw_cb(
         if (_unlikely_(ftwbuf->level == 0))
                 return FTW_CONTINUE;
 
-        label_fix(fpath, true);
+        label_fix(fpath, false, false);
 
         /* /run/initramfs is static data and big, no need to
          * dynamically relabel its contents at boot... */
@@ -364,20 +357,13 @@ static int nftw_cb(
 
 int mount_setup(bool loaded_policy) {
 
-        static const char symlinks[] =
-                "/proc/kcore\0"      "/dev/core\0"
-                "/proc/self/fd\0"    "/dev/fd\0"
-                "/proc/self/fd/0\0"  "/dev/stdin\0"
-                "/proc/self/fd/1\0"  "/dev/stdout\0"
-                "/proc/self/fd/2\0"  "/dev/stderr\0";
-
         static const char relabel[] =
                 "/run/initramfs/root-fsck\0"
                 "/run/initramfs/shutdown\0";
 
         int r;
         unsigned i;
-        const char *j, *k;
+        const char *j;
 
         for (i = 0; i < ELEMENTSOF(mount_table); i ++) {
                 r = mount_one(mount_table + i, true);
@@ -401,7 +387,7 @@ int mount_setup(bool loaded_policy) {
 
                 /* Explicitly relabel these */
                 NULSTR_FOREACH(j, relabel)
-                        label_fix(j, true);
+                        label_fix(j, true, false);
 
                 after_relabel = now(CLOCK_MONOTONIC);
 
@@ -412,12 +398,20 @@ int mount_setup(bool loaded_policy) {
         /* Create a few default symlinks, which are normally created
          * by udevd, but some scripts might need them before we start
          * udevd. */
-        NULSTR_FOREACH_PAIR(j, k, symlinks)
-                symlink_and_label(j, k);
+        dev_setup("");
+
+        /* Mark the root directory as shared in regards to mount
+         * propagation. The kernel defaults to "private", but we think
+         * it makes more sense to have a default of "shared" so that
+         * nspawn and the container tools work out of the box. If
+         * specific setups need other settings they can reset the
+         * propagation mode to private if needed. */
+        if (mount(NULL, "/", NULL, MS_REC|MS_SHARED, NULL) < 0)
+                log_warning("Failed to set up the root directory for shared mount propagation: %m");
 
         /* Create a few directories we always want around */
-        label_mkdir("/run/systemd", 0755);
-        label_mkdir("/run/systemd/system", 0755);
+        mkdir_label("/run/systemd", 0755);
+        mkdir_label("/run/systemd/system", 0755);
 
         return 0;
 }