./tools/notsd-move

1 files changed, 616 insertions, 0 deletions

diff --git a/src/grp-system/systemd-shutdown/umount.c b/src/grp-system/systemd-shutdown/umount.c
new file mode 100644
index 0000000000..1947b58c99
--- /dev/null
+++ b/src/grp-system/systemd-shutdown/umount.c
@@ -0,0 +1,616 @@
+/***
+  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 <linux/dm-ioctl.h>
+#include <linux/loop.h>
+
+#include <libudev.h>
+
+#include "core/mount-setup.h"
+#include "systemd-basic/alloc-util.h"
+#include "systemd-basic/escape.h"
+#include "systemd-basic/fd-util.h"
+#include "systemd-basic/list.h"
+#include "systemd-basic/path-util.h"
+#include "systemd-basic/string-util.h"
+#include "systemd-basic/util.h"
+#include "systemd-basic/virt.h"
+#include "systemd-shared/fstab-util.h"
+#include "systemd-shared/udev-util.h"
+
+#include "umount.h"
+
+typedef struct MountPoint {
+        char *path;
+        char *options;
+        dev_t devnum;
+        LIST_FIELDS(struct MountPoint, mount_point);
+} MountPoint;
+
+static void mount_point_free(MountPoint **head, MountPoint *m) {
+        assert(head);
+        assert(m);
+
+        LIST_REMOVE(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) {
+        _cleanup_fclose_ FILE *proc_self_mountinfo = NULL;
+        unsigned int i;
+        int r;
+
+        assert(head);
+
+        proc_self_mountinfo = fopen("/proc/self/mountinfo", "re");
+        if (!proc_self_mountinfo)
+                return -errno;
+
+        for (i = 1;; i++) {
+                _cleanup_free_ char *path = NULL, *options = NULL;
+                char *p = NULL;
+                MountPoint *m;
+                int k;
+
+                k = fscanf(proc_self_mountinfo,
+                           "%*s "       /* (1) mount id */
+                           "%*s "       /* (2) parent id */
+                           "%*s "       /* (3) major:minor */
+                           "%*s "       /* (4) root */
+                           "%ms "       /* (5) mount point */
+                           "%*s"        /* (6) mount flags */
+                           "%*[^-]"     /* (7) optional fields */
+                           "- "         /* (8) separator */
+                           "%*s "       /* (9) file system type */
+                           "%*s"        /* (10) mount source */
+                           "%ms"        /* (11) mount options */
+                           "%*[^\n]",   /* some rubbish at the end */
+                           &path, &options);
+                if (k != 2) {
+                        if (k == EOF)
+                                break;
+
+                        log_warning("Failed to parse /proc/self/mountinfo:%u.", i);
+                        continue;
+                }
+
+                r = cunescape(path, UNESCAPE_RELAX, &p);
+                if (r < 0)
+                        return r;
+
+                /* Ignore mount points we can't unmount because they
+                 * are API or because we are keeping them open (like
+                 * /dev/console). Also, ignore all mounts below API
+                 * file systems, since they are likely virtual too,
+                 * and hence not worth spending time on. Also, in
+                 * unprivileged containers we might lack the rights to
+                 * unmount these things, hence don't bother. */
+                if (mount_point_is_api(p) ||
+                    mount_point_ignore(p) ||
+                    path_startswith(p, "/dev") ||
+                    path_startswith(p, "/sys") ||
+                    path_startswith(p, "/proc")) {
+                        free(p);
+                        continue;
+                }
+
+                m = new0(MountPoint, 1);
+                if (!m) {
+                        free(p);
+                        return -ENOMEM;
+                }
+
+                m->path = p;
+                m->options = options;
+                options = NULL;
+
+                LIST_PREPEND(mount_point, *head, m);
+        }
+
+        return 0;
+}
+
+static int swap_list_get(MountPoint **head) {
+        _cleanup_fclose_ FILE *proc_swaps = NULL;
+        unsigned int i;
+        int r;
+
+        assert(head);
+
+        proc_swaps = fopen("/proc/swaps", "re");
+        if (!proc_swaps)
+                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;
+
+                k = fscanf(proc_swaps,
+                           "%ms " /* device/file */
+                           "%*s " /* type of swap */
+                           "%*s " /* swap size */
+                           "%*s " /* used */
+                           "%*s\n", /* priority */
+                           &dev);
+
+                if (k != 1) {
+                        if (k == EOF)
+                                break;
+
+                        log_warning("Failed to parse /proc/swaps:%u.", i);
+                        free(dev);
+                        continue;
+                }
+
+                if (endswith(dev, " (deleted)")) {
+                        free(dev);
+                        continue;
+                }
+
+                r = cunescape(dev, UNESCAPE_RELAX, &d);
+                free(dev);
+                if (r < 0)
+                        return r;
+
+                swap = new0(MountPoint, 1);
+                if (!swap) {
+                        free(d);
+                        return -ENOMEM;
+                }
+
+                swap->path = d;
+                LIST_PREPEND(mount_point, *head, swap);
+        }
+
+        return 0;
+}
+
+static int loopback_list_get(MountPoint **head) {
+        _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
+        struct udev_list_entry *item = NULL, *first = NULL;
+        _cleanup_udev_unref_ struct udev *udev = NULL;
+        int r;
+
+        assert(head);
+
+        udev = udev_new();
+        if (!udev)
+                return -ENOMEM;
+
+        e = udev_enumerate_new(udev);
+        if (!e)
+                return -ENOMEM;
+
+        r = udev_enumerate_add_match_subsystem(e, "block");
+        if (r < 0)
+                return r;
+
+        r = udev_enumerate_add_match_sysname(e, "loop*");
+        if (r < 0)
+                return r;
+
+        r = udev_enumerate_add_match_sysattr(e, "loop/backing_file", NULL);
+        if (r < 0)
+                return r;
+
+        r = udev_enumerate_scan_devices(e);
+        if (r < 0)
+                return r;
+
+        first = udev_enumerate_get_list_entry(e);
+        udev_list_entry_foreach(item, first) {
+                MountPoint *lb;
+                _cleanup_udev_device_unref_ struct udev_device *d;
+                char *loop;
+                const char *dn;
+
+                d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
+                if (!d)
+                        return -ENOMEM;
+
+                dn = udev_device_get_devnode(d);
+                if (!dn)
+                        continue;
+
+                loop = strdup(dn);
+                if (!loop)
+                        return -ENOMEM;
+
+                lb = new0(MountPoint, 1);
+                if (!lb) {
+                        free(loop);
+                        return -ENOMEM;
+                }
+
+                lb->path = loop;
+                LIST_PREPEND(mount_point, *head, lb);
+        }
+
+        return 0;
+}
+
+static int dm_list_get(MountPoint **head) {
+        _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
+        struct udev_list_entry *item = NULL, *first = NULL;
+        _cleanup_udev_unref_ struct udev *udev = NULL;
+        int r;
+
+        assert(head);
+
+        udev = udev_new();
+        if (!udev)
+                return -ENOMEM;
+
+        e = udev_enumerate_new(udev);
+        if (!e)
+                return -ENOMEM;
+
+        r = udev_enumerate_add_match_subsystem(e, "block");
+        if (r < 0)
+                return r;
+
+        r = udev_enumerate_add_match_sysname(e, "dm-*");
+        if (r < 0)
+                return r;
+
+        r = udev_enumerate_scan_devices(e);
+        if (r < 0)
+                return r;
+
+        first = udev_enumerate_get_list_entry(e);
+        udev_list_entry_foreach(item, first) {
+                MountPoint *m;
+                _cleanup_udev_device_unref_ struct udev_device *d;
+                dev_t devnum;
+                char *node;
+                const char *dn;
+
+                d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
+                if (!d)
+                        return -ENOMEM;
+
+                devnum = udev_device_get_devnum(d);
+                dn = udev_device_get_devnode(d);
+                if (major(devnum) == 0 || !dn)
+                        continue;
+
+                node = strdup(dn);
+                if (!node)
+                        return -ENOMEM;
+
+                m = new(MountPoint, 1);
+                if (!m) {
+                        free(node);
+                        return -ENOMEM;
+                }
+
+                m->path = node;
+                m->devnum = devnum;
+                LIST_PREPEND(mount_point, *head, m);
+        }
+
+        return 0;
+}
+
+static int delete_loopback(const char *device) {
+        _cleanup_close_ int fd = -1;
+        int r;
+
+        fd = open(device, O_RDONLY|O_CLOEXEC);
+        if (fd < 0)
+                return errno == ENOENT ? 0 : -errno;
+
+        r = ioctl(fd, LOOP_CLR_FD, 0);
+        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) {
+        _cleanup_close_ int fd = -1;
+        int r;
+        struct dm_ioctl dm = {
+                .version = {DM_VERSION_MAJOR,
+                            DM_VERSION_MINOR,
+                            DM_VERSION_PATCHLEVEL},
+                .data_size = sizeof(dm),
+                .dev = devnum,
+        };
+
+        assert(major(devnum) != 0);
+
+        fd = open("/dev/mapper/control", O_RDWR|O_CLOEXEC);
+        if (fd < 0)
+                return -errno;
+
+        r = ioctl(fd, DM_DEV_REMOVE, &dm);
+        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 we are in a container, don't attempt to
+                   read-only mount anything as that brings no real
+                   benefits, but might confuse the host, as we remount
+                   the superblock here, not the bind mount. */
+                if (detect_container() <= 0)  {
+                        _cleanup_free_ char *options = NULL;
+                        /* MS_REMOUNT requires that the data parameter
+                         * should be the same from the original mount
+                         * except for the desired changes. Since we want
+                         * to remount read-only, we should filter out
+                         * rw (and ro too, because it confuses the kernel) */
+                        (void) fstab_filter_options(m->options, "rw\0ro\0", NULL, NULL, &options);
+
+                        /* We always try to remount directories
+                         * read-only first, before we go on and umount
+                         * them.
+                         *
+                         * Mount points can be stacked. If a mount
+                         * point is stacked below / or /usr, we
+                         * cannot umount or remount it directly,
+                         * since there is no way to refer to the
+                         * underlying mount. There's nothing we can do
+                         * about it for the general case, but we can
+                         * do something about it if it is aliased
+                         * somehwere else via a bind mount. If we
+                         * explicitly remount the super block of that
+                         * alias read-only we hence should be
+                         * relatively safe regarding keeping the fs we
+                         * can otherwise not see dirty. */
+                        log_info("Remounting '%s' read-only with options '%s'.", m->path, options);
+                        (void) mount(NULL, m->path, NULL, MS_REMOUNT|MS_RDONLY, options);
+                }
+
+                /* Skip / and /usr since we cannot unmount that
+                 * anyway, since we are running from it. They have
+                 * already been remounted ro. */
+                if (path_equal(m->path, "/")
+#ifndef HAVE_SPLIT_USR
+                    || path_equal(m->path, "/usr")
+#endif
+                    || path_startswith(m->path, "/run/initramfs")
+                )
+                        continue;
+
+                /* Trying to umount. We don't force here since we rely
+                 * on busy NFS and FUSE file systems to return EBUSY
+                 * until we closed everything on top of them. */
+                log_info("Unmounting %s.", m->path);
+                if (umount2(m->path, 0) == 0) {
+                        if (changed)
+                                *changed = true;
+
+                        mount_point_free(head, m);
+                } else if (log_error) {
+                        log_warning_errno(errno, "Could not unmount %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) {
+                log_info("Deactivating swap %s.", m->path);
+                if (swapoff(m->path) == 0) {
+                        if (changed)
+                                *changed = true;
+
+                        mount_point_free(head, m);
+                } else {
+                        log_warning_errno(errno, "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;
+                }
+
+                log_info("Detaching loopback %s.", m->path);
+                r = delete_loopback(m->path);
+                if (r >= 0) {
+                        if (r > 0 && changed)
+                                *changed = true;
+
+                        mount_point_free(head, m);
+                } else {
+                        log_warning_errno(errno, "Could not detach 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;
+                }
+
+                log_info("Detaching DM %u:%u.", major(m->devnum), minor(m->devnum));
+                r = delete_dm(m->devnum);
+                if (r >= 0) {
+                        if (changed)
+                                *changed = true;
+
+                        mount_point_free(head, m);
+                } else {
+                        log_warning_errno(errno, "Could not detach 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(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;
+
+  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(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(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(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;
+}