| /*-*- 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 "path-util.h" |
| #include "util.h" |
| #include "virt.h" |
| |
| typedef struct MountPoint { |
| char *path; |
| 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(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; |
| |
| path = p = NULL; |
| |
| if ((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 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 */ |
| &path)) != 1) { |
| if (k == EOF) |
| break; |
| |
| log_warning("Failed to parse /proc/self/mountinfo:%u.", i); |
| |
| free(path); |
| continue; |
| } |
| |
| 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; |
| 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 || |
| udev_enumerate_add_match_sysattr(e, "loop/backing_file", NULL) < 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) { |
| _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 mound. */ |
| if (detect_container(NULL) <= 0) { |
| /* 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. */ |
| mount(NULL, m->path, NULL, MS_REMOUNT|MS_RDONLY, NULL); |
| } |
| |
| /* 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 |
| ) |
| 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("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("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("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("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(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; |
| |
| 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; |
| } |