X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=mount-setup.c;h=a804030df00242050ba62cafdef3ba6533a400e2;hp=f3041941ac4326d070b1325a6a159c9f7da83cb2;hb=8d567588cad053f79abe603ab113e1b85a92f1da;hpb=11857f8daf5a6336865844dedff365f9fa22c8f4;ds=sidebyside

diff --git a/mount-setup.c b/mount-setup.c
index f3041941a..a804030df 100644
--- a/mount-setup.c
+++ b/mount-setup.c
@@ -32,57 +32,44 @@
 #include "macro.h"
 #include "util.h"
 
-enum {
-        MOUNT_WHAT,
-        MOUNT_WHERE,
-        MOUNT_TYPE,
-        MOUNT_OPTIONS,
-        MOUNT_SKIP
+typedef struct MountPoint {
+        const char *what;
+        const char *where;
+        const char *type;
+        const char *options;
+        unsigned long flags;
+        bool fatal;
+} MountPoint;
+
+static const MountPoint mount_table[] = {
+        { "proc",    "/proc",             "proc",     NULL,        MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
+        { "sysfs",   "/sys",              "sysfs",    NULL,        MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
+        { "devtmps", "/dev",              "devtmpfs", "mode=755",  MS_NOSUID,                    true },
+        { "tmpfs",   "/dev/shm",          "tmpfs",    "mode=1777", MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
+        { "devpts",  "/dev/pts",          "devpts",   NULL,        MS_NOSUID|MS_NOEXEC|MS_NODEV, false },
+        { "cgroup",  "/cgroup/debug",     "cgroup",   "debug",     MS_NOSUID|MS_NOEXEC|MS_NODEV, true },
+        { "debugfs", "/sys/kernel/debug", "debugfs",  NULL,        MS_NOSUID|MS_NOEXEC|MS_NODEV, false }
 };
 
-static const char *table[] = {
-        "proc",    "/proc",             "proc",     NULL,
-        "sysfs",   "/sys",              "sysfs",    NULL,
-        "devtmps", "/dev",              "devtmpfs", "mode=755",
-        "tmpfs",   "/dev/shm",          "tmpfs",    "mode=1777",
-        "devpts",  "/dev/pts",          "devpts",   NULL,
-        "cgroup",  "/cgroup/debug",     "cgroup",   "debug",
-        "debugfs", "/sys/kernel/debug", "debugfs",  NULL,
-        NULL
-};
-
-static int is_mount_point(const char *t) {
-        struct stat a, b;
-        char *copy;
-
-        if (lstat(t, &a) < 0) {
-
-                if (errno == ENOENT)
-                        return 0;
-
-                return -errno;
-        }
-
-        if (!(copy = strdup(t)))
-                return -ENOMEM;
+bool mount_point_is_api(const char *path) {
+        unsigned i;
 
-        if (lstat(dirname(copy), &b) < 0) {
-                free(copy);
-                return -errno;
-        }
-
-        free(copy);
+        /* Checks if this mount point is considered "API", and hence
+         * should be ignored */
 
-        return a.st_dev != b.st_dev;
+        for (i = 0; i < ELEMENTSOF(mount_table); i ++)
+                if (path_startswith(path, mount_table[i].where))
+                        return true;
 
+        return false;
 }
 
-static int mount_one(const char *t[]) {
+static int mount_one(const MountPoint *p) {
         int r;
 
-        assert(t);
+        assert(p);
 
-        if ((r = is_mount_point(t[MOUNT_WHERE])) < 0)
+        if ((r = path_is_mount_point(p->where)) < 0)
                 return r;
 
         if (r > 0)
@@ -90,33 +77,90 @@ static int mount_one(const char *t[]) {
 
         /* The access mode here doesn't really matter too much, since
          * the mounted file system will take precedence anyway. */
-        mkdir_p(t[MOUNT_WHERE], 0755);
+        mkdir_p(p->where, 0755);
 
         log_debug("Mounting %s to %s of type %s with options %s.",
-                  t[MOUNT_WHAT],
-                  t[MOUNT_WHERE],
-                  t[MOUNT_TYPE],
-                  strna(t[MOUNT_OPTIONS]));
-
-        if (mount(t[MOUNT_WHAT],
-                  t[MOUNT_WHERE],
-                  t[MOUNT_TYPE],
-                  0,
-                  t[MOUNT_OPTIONS]) < 0) {
-                log_error("Failed to mount %s: %s", t[MOUNT_WHERE], strerror(errno));
-                return -errno;
+                  p->what,
+                  p->where,
+                  p->type,
+                  strna(p->options));
+
+        if (mount(p->what,
+                  p->where,
+                  p->type,
+                  p->flags,
+                  p->options) < 0) {
+                log_error("Failed to mount %s: %s", p->where, strerror(errno));
+                return p->fatal ? -errno : 0;
         }
 
         return 0;
 }
 
+static int mount_cgroup_controllers(void) {
+        int r;
+        FILE *f;
+        char buf [256];
+
+        /* Mount all available cgroup controllers. */
+
+        if (!(f = fopen("/proc/cgroups", "re")))
+                return -ENOENT;
+
+        /* Ignore the header line */
+        fgets(buf, sizeof(buf), f);
+
+        for (;;) {
+                MountPoint p;
+                char *controller, *where;
+
+                if (fscanf(f, "%ms %*i %*i %*i", &controller) != 1) {
+
+                        if (feof(f))
+                                break;
+
+                        log_error("Failed to parse /proc/cgroups.");
+                        r = -EIO;
+                        goto finish;
+                }
+
+                if (asprintf(&where, "/cgroup/%s", controller) < 0) {
+                        free(controller);
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                zero(p);
+                p.what = "cgroup";
+                p.where = where;
+                p.type = "cgroup";
+                p.options = controller;
+                p.flags = MS_NOSUID|MS_NOEXEC|MS_NODEV;
+                p.fatal = false;
+
+                r = mount_one(&p);
+                free(controller);
+                free(where);
+
+                if (r < 0)
+                        goto finish;
+        }
+
+        r = 0;
+
+finish:
+        fclose(f);
+
+        return r;
+}
+
 int mount_setup(void) {
         int r;
-        const char **t;
+        unsigned i;
 
-        for (t = table; *t; t += MOUNT_SKIP)
-                if ((r = mount_one(t)) < 0)
+        for (i = 0; i < ELEMENTSOF(mount_table); i ++)
+                if ((r = mount_one(mount_table+i)) < 0)
                         return r;
 
-        return 0;
+        return mount_cgroup_controllers();
 }