shutdown: move shutdown to core since it replaces PID 1

1 files changed, 649 insertions, 0 deletions

diff --git a/src/core/umount.c b/src/core/umount.c
new file mode 100644
index 0000000000..488e1e4a4d
--- /dev/null
+++ b/src/core/umount.c
@@ -0,0 +1,649 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 ProFUSION embedded systems
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <sys/swap.h>
+#include <unistd.h>
+#include <linux/loop.h>
+#include <linux/dm-ioctl.h>
+#include <libudev.h>
+
+#include "list.h"
+#include "mount-setup.h"
+#include "umount.h"
+#include "util.h"
+
+typedef struct MountPoint {
+        char *path;
+        dev_t devnum;
+        bool skip_ro;
+        LIST_FIELDS (struct MountPoint, mount_point);
+} MountPoint;
+
+static void mount_point_free(MountPoint **head, MountPoint *m) {
+        assert(head);
+        assert(m);
+
+        LIST_REMOVE(MountPoint, mount_point, *head, m);
+
+        free(m->path);
+        free(m);
+}
+
+static void mount_points_list_free(MountPoint **head) {
+        assert(head);
+
+        while (*head)
+                mount_point_free(head, *head);
+}
+
+static int mount_points_list_get(MountPoint **head) {
+        FILE *proc_self_mountinfo;
+        char *path, *p;
+        unsigned int i;
+        int r;
+
+        assert(head);
+
+        if (!(proc_self_mountinfo = fopen("/proc/self/mountinfo", "re")))
+                return -errno;
+
+        for (i = 1;; i++) {
+                int k;
+                MountPoint *m;
+                char *root;
+                bool skip_ro;
+
+                path = p = NULL;
+
+                if ((k = fscanf(proc_self_mountinfo,
+                                "%*s "       /* (1) mount id */
+                                "%*s "       /* (2) parent id */
+                                "%*s "       /* (3) major:minor */
+                                "%ms "       /* (4) root */
+                                "%ms "       /* (5) mount point */
+                                "%*s"        /* (6) mount options */
+                                "%*[^-]"     /* (7) optional fields */
+                                "- "         /* (8) separator */
+                                "%*s "       /* (9) file system type */
+                                "%*s"        /* (10) mount source */
+                                "%*s"        /* (11) mount options 2 */
+                                "%*[^\n]",   /* some rubbish at the end */
+                                &root,
+                                &path)) != 2) {
+                        if (k == EOF)
+                                break;
+
+                        log_warning("Failed to parse /proc/self/mountinfo:%u.", i);
+
+                        free(path);
+                        continue;
+                }
+
+                /* If we encounter a bind mount, don't try to remount
+                 * the source dir too early */
+                skip_ro = !streq(root, "/");
+                free(root);
+
+                p = cunescape(path);
+                free(path);
+
+                if (!p) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                /* Ignore mount points we can't unmount because they
+                 * are API or because we are keeping them open (like
+                 * /dev/console) */
+                if (mount_point_is_api(p) ||
+                    mount_point_ignore(p) ||
+                    path_equal(p, "/dev/console")) {
+                        free(p);
+                        continue;
+                }
+
+                if (!(m = new0(MountPoint, 1))) {
+                        free(p);
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                m->path = p;
+                m->skip_ro = skip_ro;
+                LIST_PREPEND(MountPoint, mount_point, *head, m);
+        }
+
+        r = 0;
+
+finish:
+        fclose(proc_self_mountinfo);
+
+        return r;
+}
+
+static int swap_list_get(MountPoint **head) {
+        FILE *proc_swaps;
+        unsigned int i;
+        int r;
+
+        assert(head);
+
+        if (!(proc_swaps = fopen("/proc/swaps", "re")))
+                return (errno == ENOENT) ? 0 : -errno;
+
+        (void) fscanf(proc_swaps, "%*s %*s %*s %*s %*s\n");
+
+        for (i = 2;; i++) {
+                MountPoint *swap;
+                char *dev = NULL, *d;
+                int k;
+
+                if ((k = fscanf(proc_swaps,
+                                "%ms " /* device/file */
+                                "%*s " /* type of swap */
+                                "%*s " /* swap size */
+                                "%*s " /* used */
+                                "%*s\n", /* priority */
+                                &dev)) != 1) {
+
+                        if (k == EOF)
+                                break;
+
+                        log_warning("Failed to parse /proc/swaps:%u.", i);
+
+                        free(dev);
+                        continue;
+                }
+
+                if (endswith(dev, "(deleted)")) {
+                        free(dev);
+                        continue;
+                }
+
+                d = cunescape(dev);
+                free(dev);
+
+                if (!d) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                if (!(swap = new0(MountPoint, 1))) {
+                        free(d);
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                swap->path = d;
+                LIST_PREPEND(MountPoint, mount_point, *head, swap);
+        }
+
+        r = 0;
+
+finish:
+        fclose(proc_swaps);
+
+        return r;
+}
+
+static int loopback_list_get(MountPoint **head) {
+        int r;
+        struct udev *udev;
+        struct udev_enumerate *e = NULL;
+        struct udev_list_entry *item = NULL, *first = NULL;
+
+        assert(head);
+
+        if (!(udev = udev_new())) {
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        if (!(e = udev_enumerate_new(udev))) {
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        if (udev_enumerate_add_match_subsystem(e, "block") < 0 ||
+            udev_enumerate_add_match_sysname(e, "loop*") < 0) {
+                r = -EIO;
+                goto finish;
+        }
+
+        if (udev_enumerate_scan_devices(e) < 0) {
+                r = -EIO;
+                goto finish;
+        }
+
+        first = udev_enumerate_get_list_entry(e);
+        udev_list_entry_foreach(item, first) {
+                MountPoint *lb;
+                struct udev_device *d;
+                char *loop;
+                const char *dn;
+
+                if (!(d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item)))) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                if (!(dn = udev_device_get_devnode(d))) {
+                        udev_device_unref(d);
+                        continue;
+                }
+
+                loop = strdup(dn);
+                udev_device_unref(d);
+
+                if (!loop) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                if (!(lb = new0(MountPoint, 1))) {
+                        free(loop);
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                lb->path = loop;
+                LIST_PREPEND(MountPoint, mount_point, *head, lb);
+        }
+
+        r = 0;
+
+finish:
+        if (e)
+                udev_enumerate_unref(e);
+
+        if (udev)
+                udev_unref(udev);
+
+        return r;
+}
+
+static int dm_list_get(MountPoint **head) {
+        int r;
+        struct udev *udev;
+        struct udev_enumerate *e = NULL;
+        struct udev_list_entry *item = NULL, *first = NULL;
+
+        assert(head);
+
+        if (!(udev = udev_new())) {
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        if (!(e = udev_enumerate_new(udev))) {
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        if (udev_enumerate_add_match_subsystem(e, "block") < 0 ||
+            udev_enumerate_add_match_sysname(e, "dm-*") < 0) {
+                r = -EIO;
+                goto finish;
+        }
+
+        if (udev_enumerate_scan_devices(e) < 0) {
+                r = -EIO;
+                goto finish;
+        }
+
+        first = udev_enumerate_get_list_entry(e);
+
+        udev_list_entry_foreach(item, first) {
+                MountPoint *m;
+                struct udev_device *d;
+                dev_t devnum;
+                char *node;
+                const char *dn;
+
+                if (!(d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item)))) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                devnum = udev_device_get_devnum(d);
+                dn = udev_device_get_devnode(d);
+
+                if (major(devnum) == 0 || !dn) {
+                        udev_device_unref(d);
+                        continue;
+                }
+
+                node = strdup(dn);
+                udev_device_unref(d);
+
+                if (!node) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                if (!(m = new(MountPoint, 1))) {
+                        free(node);
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                m->path = node;
+                m->devnum = devnum;
+                LIST_PREPEND(MountPoint, mount_point, *head, m);
+        }
+
+        r = 0;
+
+finish:
+        if (e)
+                udev_enumerate_unref(e);
+
+        if (udev)
+                udev_unref(udev);
+
+        return r;
+}
+
+static int delete_loopback(const char *device) {
+        int fd, r;
+
+        if ((fd = open(device, O_RDONLY|O_CLOEXEC)) < 0)
+                return errno == ENOENT ? 0 : -errno;
+
+        r = ioctl(fd, LOOP_CLR_FD, 0);
+        close_nointr_nofail(fd);
+
+        if (r >= 0)
+                return 1;
+
+        /* ENXIO: not bound, so no error */
+        if (errno == ENXIO)
+                return 0;
+
+        return -errno;
+}
+
+static int delete_dm(dev_t devnum) {
+        int fd, r;
+        struct dm_ioctl dm;
+
+        assert(major(devnum) != 0);
+
+        if ((fd = open("/dev/mapper/control", O_RDWR|O_CLOEXEC)) < 0)
+                return -errno;
+
+        zero(dm);
+        dm.version[0] = DM_VERSION_MAJOR;
+        dm.version[1] = DM_VERSION_MINOR;
+        dm.version[2] = DM_VERSION_PATCHLEVEL;
+
+        dm.data_size = sizeof(dm);
+        dm.dev = devnum;
+
+        r = ioctl(fd, DM_DEV_REMOVE, &dm);
+        close_nointr_nofail(fd);
+
+        return r >= 0 ? 0 : -errno;
+}
+
+static int mount_points_list_umount(MountPoint **head, bool *changed, bool log_error) {
+        MountPoint *m, *n;
+        int n_failed = 0;
+
+        assert(head);
+
+        LIST_FOREACH_SAFE(mount_point, m, n, *head) {
+                if (path_equal(m->path, "/")
+#ifndef HAVE_SPLIT_USR
+                    || path_equal(m->path, "/usr")
+#endif
+                ) {
+                        n_failed++;
+                        continue;
+                }
+
+                /* Trying to umount. Forcing to umount if busy (only for NFS mounts) */
+                if (umount2(m->path, MNT_FORCE) == 0) {
+                        log_info("Unmounted %s.", m->path);
+                        if (changed)
+                                *changed = true;
+
+                        mount_point_free(head, m);
+                } else if (log_error) {
+                        log_warning("Could not unmount %s: %m", m->path);
+                        n_failed++;
+                }
+        }
+
+        return n_failed;
+}
+
+static int mount_points_list_remount_read_only(MountPoint **head, bool *changed) {
+        MountPoint *m, *n;
+        int n_failed = 0;
+
+        assert(head);
+
+        LIST_FOREACH_SAFE(mount_point, m, n, *head) {
+
+                if (m->skip_ro) {
+                        n_failed++;
+                        continue;
+                }
+
+                /* Trying to remount read-only */
+                if (mount(NULL, m->path, NULL, MS_MGC_VAL|MS_REMOUNT|MS_RDONLY, NULL) == 0) {
+                        if (changed)
+                                *changed = true;
+
+                        mount_point_free(head, m);
+                } else {
+                        log_warning("Could not remount as read-only %s: %m", m->path);
+                        n_failed++;
+                }
+        }
+
+        return n_failed;
+}
+
+static int swap_points_list_off(MountPoint **head, bool *changed) {
+        MountPoint *m, *n;
+        int n_failed = 0;
+
+        assert(head);
+
+        LIST_FOREACH_SAFE(mount_point, m, n, *head) {
+                if (swapoff(m->path) == 0) {
+                        if (changed)
+                                *changed = true;
+
+                        mount_point_free(head, m);
+                } else {
+                        log_warning("Could not deactivate swap %s: %m", m->path);
+                        n_failed++;
+                }
+        }
+
+        return n_failed;
+}
+
+static int loopback_points_list_detach(MountPoint **head, bool *changed) {
+        MountPoint *m, *n;
+        int n_failed = 0, k;
+        struct stat root_st;
+
+        assert(head);
+
+        k = lstat("/", &root_st);
+
+        LIST_FOREACH_SAFE(mount_point, m, n, *head) {
+                int r;
+                struct stat loopback_st;
+
+                if (k >= 0 &&
+                    major(root_st.st_dev) != 0 &&
+                    lstat(m->path, &loopback_st) >= 0 &&
+                    root_st.st_dev == loopback_st.st_rdev) {
+                        n_failed ++;
+                        continue;
+                }
+
+                if ((r = delete_loopback(m->path)) >= 0) {
+
+                        if (r > 0 && changed)
+                                *changed = true;
+
+                        mount_point_free(head, m);
+                } else {
+                        log_warning("Could not delete loopback %s: %m", m->path);
+                        n_failed++;
+                }
+        }
+
+        return n_failed;
+}
+
+static int dm_points_list_detach(MountPoint **head, bool *changed) {
+        MountPoint *m, *n;
+        int n_failed = 0, k;
+        struct stat root_st;
+
+        assert(head);
+
+        k = lstat("/", &root_st);
+
+        LIST_FOREACH_SAFE(mount_point, m, n, *head) {
+                int r;
+
+                if (k >= 0 &&
+                    major(root_st.st_dev) != 0 &&
+                    root_st.st_dev == m->devnum) {
+                        n_failed ++;
+                        continue;
+                }
+
+                if ((r = delete_dm(m->devnum)) >= 0) {
+
+                        if (r > 0 && changed)
+                                *changed = true;
+
+                        mount_point_free(head, m);
+                } else {
+                        log_warning("Could not delete dm %s: %m", m->path);
+                        n_failed++;
+                }
+        }
+
+        return n_failed;
+}
+
+int umount_all(bool *changed) {
+        int r;
+        bool umount_changed;
+
+        LIST_HEAD(MountPoint, mp_list_head);
+
+        LIST_HEAD_INIT(MountPoint, mp_list_head);
+
+        r = mount_points_list_get(&mp_list_head);
+        if (r < 0)
+                goto end;
+
+        /* retry umount, until nothing can be umounted anymore */
+        do {
+                umount_changed = false;
+
+                mount_points_list_umount(&mp_list_head, &umount_changed, false);
+                if (umount_changed)
+                        *changed = true;
+
+        } while (umount_changed);
+
+        /* umount one more time with logging enabled */
+        r = mount_points_list_umount(&mp_list_head, &umount_changed, true);
+        if (r <= 0)
+                goto end;
+
+        r = mount_points_list_remount_read_only(&mp_list_head, changed);
+
+  end:
+        mount_points_list_free(&mp_list_head);
+
+        return r;
+}
+
+int swapoff_all(bool *changed) {
+        int r;
+        LIST_HEAD(MountPoint, swap_list_head);
+
+        LIST_HEAD_INIT(MountPoint, swap_list_head);
+
+        r = swap_list_get(&swap_list_head);
+        if (r < 0)
+                goto end;
+
+        r = swap_points_list_off(&swap_list_head, changed);
+
+  end:
+        mount_points_list_free(&swap_list_head);
+
+        return r;
+}
+
+int loopback_detach_all(bool *changed) {
+        int r;
+        LIST_HEAD(MountPoint, loopback_list_head);
+
+        LIST_HEAD_INIT(MountPoint, loopback_list_head);
+
+        r = loopback_list_get(&loopback_list_head);
+        if (r < 0)
+                goto end;
+
+        r = loopback_points_list_detach(&loopback_list_head, changed);
+
+  end:
+        mount_points_list_free(&loopback_list_head);
+
+        return r;
+}
+
+int dm_detach_all(bool *changed) {
+        int r;
+        LIST_HEAD(MountPoint, dm_list_head);
+
+        LIST_HEAD_INIT(MountPoint, dm_list_head);
+
+        r = dm_list_get(&dm_list_head);
+        if (r < 0)
+                goto end;
+
+        r = dm_points_list_detach(&dm_list_head, changed);
+
+  end:
+        mount_points_list_free(&dm_list_head);
+
+        return r;
+}