| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| /*** |
| Copyright © 2010 ProFUSION embedded systems |
| ***/ |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <linux/dm-ioctl.h> |
| #include <linux/major.h> |
| #include <linux/raid/md_u.h> |
| #include <linux/loop.h> |
| #include <sys/mount.h> |
| #include <sys/swap.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| #if HAVE_VALGRIND_MEMCHECK_H |
| #include <valgrind/memcheck.h> |
| #endif |
| |
| #include "sd-device.h" |
| |
| #include "alloc-util.h" |
| #include "blockdev-util.h" |
| #include "chase-symlinks.h" |
| #include "constants.h" |
| #include "device-util.h" |
| #include "dirent-util.h" |
| #include "escape.h" |
| #include "fd-util.h" |
| #include "fileio.h" |
| #include "fs-util.h" |
| #include "fstab-util.h" |
| #include "libmount-util.h" |
| #include "mkdir.h" |
| #include "mount-setup.h" |
| #include "mount-util.h" |
| #include "mountpoint-util.h" |
| #include "parse-util.h" |
| #include "path-util.h" |
| #include "process-util.h" |
| #include "random-util.h" |
| #include "signal-util.h" |
| #include "stat-util.h" |
| #include "string-util.h" |
| #include "strv.h" |
| #include "sync-util.h" |
| #include "umount.h" |
| #include "virt.h" |
| |
| static void mount_point_free(MountPoint **head, MountPoint *m) { |
| assert(head); |
| assert(m); |
| |
| LIST_REMOVE(mount_point, *head, m); |
| |
| free(m->path); |
| free(m->remount_options); |
| free(m); |
| } |
| |
| void mount_points_list_free(MountPoint **head) { |
| assert(head); |
| |
| while (*head) |
| mount_point_free(head, *head); |
| } |
| |
| int mount_points_list_get(const char *mountinfo, MountPoint **head) { |
| _cleanup_(mnt_free_tablep) struct libmnt_table *table = NULL; |
| _cleanup_(mnt_free_iterp) struct libmnt_iter *iter = NULL; |
| int r; |
| |
| assert(head); |
| |
| r = libmount_parse(mountinfo, NULL, &table, &iter); |
| if (r < 0) |
| return log_error_errno(r, "Failed to parse %s: %m", mountinfo ?: "/proc/self/mountinfo"); |
| |
| for (;;) { |
| _cleanup_free_ char *options = NULL, *remount_options = NULL; |
| struct libmnt_fs *fs; |
| const char *path, *fstype; |
| unsigned long remount_flags = 0u; |
| bool try_remount_ro, is_api_vfs; |
| _cleanup_free_ MountPoint *m = NULL; |
| |
| r = mnt_table_next_fs(table, iter, &fs); |
| if (r == 1) /* EOF */ |
| break; |
| if (r < 0) |
| return log_error_errno(r, "Failed to get next entry from %s: %m", mountinfo ?: "/proc/self/mountinfo"); |
| |
| path = mnt_fs_get_target(fs); |
| if (!path) |
| continue; |
| |
| fstype = mnt_fs_get_fstype(fs); |
| |
| /* Combine the generic VFS options with the FS-specific options. Duplicates are not a problem |
| * here, because the only options that should come up twice are typically ro/rw, which are |
| * turned into MS_RDONLY or the inversion of it. |
| * |
| * Even if there are duplicates later in mount_option_mangle() they shouldn't hurt anyways as |
| * they override each other. */ |
| if (!strextend_with_separator(&options, ",", mnt_fs_get_vfs_options(fs))) |
| return log_oom(); |
| if (!strextend_with_separator(&options, ",", mnt_fs_get_fs_options(fs))) |
| return log_oom(); |
| |
| /* 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(path) || |
| mount_point_ignore(path) || |
| PATH_STARTSWITH_SET(path, "/dev", "/sys", "/proc")) |
| continue; |
| |
| is_api_vfs = fstype_is_api_vfs(fstype); |
| |
| /* 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 the filesystem is a network fs, also skip the remount. It brings no value (we cannot |
| * leave a "dirty fs") and could hang if the network is down. Note that umount2() is more |
| * careful and will not hang because of the network being down. */ |
| try_remount_ro = detect_container() <= 0 && |
| !fstype_is_network(fstype) && |
| !is_api_vfs && |
| !fstype_is_ro(fstype) && |
| !fstab_test_yes_no_option(options, "ro\0rw\0"); |
| |
| if (try_remount_ro) { |
| /* mount(2) states that mount flags and options need to be exactly the same as they |
| * were when the filesystem was mounted, except for the desired changes. So we |
| * reconstruct both here and adjust them for the later remount call too. */ |
| |
| r = mnt_fs_get_propagation(fs, &remount_flags); |
| if (r < 0) { |
| log_warning_errno(r, "mnt_fs_get_propagation() failed for %s, ignoring: %m", path); |
| continue; |
| } |
| |
| r = mount_option_mangle(options, remount_flags, &remount_flags, &remount_options); |
| if (r < 0) { |
| log_warning_errno(r, "mount_option_mangle failed for %s, ignoring: %m", path); |
| continue; |
| } |
| |
| /* MS_BIND is special. If it is provided it will only make the mount-point |
| * read-only. If left out, the super block itself is remounted, which we want. */ |
| remount_flags = (remount_flags|MS_REMOUNT|MS_RDONLY) & ~MS_BIND; |
| } |
| |
| m = new(MountPoint, 1); |
| if (!m) |
| return log_oom(); |
| |
| r = libmount_is_leaf(table, fs); |
| if (r < 0) |
| return log_error_errno(r, "Failed to get children mounts for %s from %s: %m", path, mountinfo ?: "/proc/self/mountinfo"); |
| bool leaf = r; |
| |
| *m = (MountPoint) { |
| .remount_options = remount_options, |
| .remount_flags = remount_flags, |
| .try_remount_ro = try_remount_ro, |
| |
| /* Unmount sysfs/procfs/… lazily, since syncing doesn't matter there, and it's OK if |
| * something keeps an fd open to it. */ |
| .umount_lazily = is_api_vfs, |
| .leaf = leaf, |
| }; |
| |
| m->path = strdup(path); |
| if (!m->path) |
| return log_oom(); |
| |
| TAKE_PTR(remount_options); |
| |
| LIST_PREPEND(mount_point, *head, TAKE_PTR(m)); |
| } |
| |
| return 0; |
| } |
| |
| int swap_list_get(const char *swaps, MountPoint **head) { |
| _cleanup_(mnt_free_tablep) struct libmnt_table *t = NULL; |
| _cleanup_(mnt_free_iterp) struct libmnt_iter *i = NULL; |
| int r; |
| |
| assert(head); |
| |
| t = mnt_new_table(); |
| i = mnt_new_iter(MNT_ITER_FORWARD); |
| if (!t || !i) |
| return log_oom(); |
| |
| r = mnt_table_parse_swaps(t, swaps); |
| if (r == -ENOENT) /* no /proc/swaps is fine */ |
| return 0; |
| if (r < 0) |
| return log_error_errno(r, "Failed to parse %s: %m", swaps ?: "/proc/swaps"); |
| |
| for (;;) { |
| struct libmnt_fs *fs; |
| _cleanup_free_ MountPoint *swap = NULL; |
| const char *source; |
| |
| r = mnt_table_next_fs(t, i, &fs); |
| if (r == 1) /* EOF */ |
| break; |
| if (r < 0) |
| return log_error_errno(r, "Failed to get next entry from %s: %m", swaps ?: "/proc/swaps"); |
| |
| source = mnt_fs_get_source(fs); |
| if (!source) |
| continue; |
| |
| swap = new0(MountPoint, 1); |
| if (!swap) |
| return log_oom(); |
| |
| swap->path = strdup(source); |
| if (!swap->path) |
| return log_oom(); |
| |
| LIST_PREPEND(mount_point, *head, TAKE_PTR(swap)); |
| } |
| |
| return 0; |
| } |
| |
| static int loopback_list_get(MountPoint **head) { |
| _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL; |
| sd_device *d; |
| int r; |
| |
| assert(head); |
| |
| r = sd_device_enumerator_new(&e); |
| if (r < 0) |
| return r; |
| |
| r = sd_device_enumerator_allow_uninitialized(e); |
| if (r < 0) |
| return r; |
| |
| r = sd_device_enumerator_add_match_subsystem(e, "block", true); |
| if (r < 0) |
| return r; |
| |
| r = sd_device_enumerator_add_match_sysname(e, "loop*"); |
| if (r < 0) |
| return r; |
| |
| r = sd_device_enumerator_add_match_sysattr(e, "loop/backing_file", NULL, true); |
| if (r < 0) |
| return r; |
| |
| FOREACH_DEVICE(e, d) { |
| _cleanup_free_ char *p = NULL; |
| const char *dn; |
| MountPoint *lb; |
| dev_t devnum; |
| |
| if (sd_device_get_devnum(d, &devnum) < 0 || |
| sd_device_get_devname(d, &dn) < 0) |
| continue; |
| |
| p = strdup(dn); |
| if (!p) |
| return -ENOMEM; |
| |
| lb = new(MountPoint, 1); |
| if (!lb) |
| return -ENOMEM; |
| |
| *lb = (MountPoint) { |
| .path = TAKE_PTR(p), |
| .devnum = devnum, |
| }; |
| |
| LIST_PREPEND(mount_point, *head, lb); |
| } |
| |
| return 0; |
| } |
| |
| static int dm_list_get(MountPoint **head) { |
| _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL; |
| sd_device *d; |
| int r; |
| |
| assert(head); |
| |
| r = sd_device_enumerator_new(&e); |
| if (r < 0) |
| return r; |
| |
| r = sd_device_enumerator_allow_uninitialized(e); |
| if (r < 0) |
| return r; |
| |
| r = sd_device_enumerator_add_match_subsystem(e, "block", true); |
| if (r < 0) |
| return r; |
| |
| r = sd_device_enumerator_add_match_sysname(e, "dm-*"); |
| if (r < 0) |
| return r; |
| |
| FOREACH_DEVICE(e, d) { |
| _cleanup_free_ char *p = NULL; |
| const char *dn; |
| MountPoint *m; |
| dev_t devnum; |
| |
| if (sd_device_get_devnum(d, &devnum) < 0 || |
| sd_device_get_devname(d, &dn) < 0) |
| continue; |
| |
| p = strdup(dn); |
| if (!p) |
| return -ENOMEM; |
| |
| m = new(MountPoint, 1); |
| if (!m) |
| return -ENOMEM; |
| |
| *m = (MountPoint) { |
| .path = TAKE_PTR(p), |
| .devnum = devnum, |
| }; |
| |
| LIST_PREPEND(mount_point, *head, m); |
| } |
| |
| return 0; |
| } |
| |
| static int md_list_get(MountPoint **head) { |
| _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL; |
| sd_device *d; |
| int r; |
| |
| assert(head); |
| |
| r = sd_device_enumerator_new(&e); |
| if (r < 0) |
| return r; |
| |
| r = sd_device_enumerator_allow_uninitialized(e); |
| if (r < 0) |
| return r; |
| |
| r = sd_device_enumerator_add_match_subsystem(e, "block", true); |
| if (r < 0) |
| return r; |
| |
| r = sd_device_enumerator_add_match_sysname(e, "md*"); |
| if (r < 0) |
| return r; |
| |
| /* Filter out partitions. */ |
| r = sd_device_enumerator_add_match_property(e, "DEVTYPE", "disk"); |
| if (r < 0) |
| return r; |
| |
| FOREACH_DEVICE(e, d) { |
| _cleanup_free_ char *p = NULL; |
| const char *dn, *md_level; |
| MountPoint *m; |
| dev_t devnum; |
| |
| if (sd_device_get_devnum(d, &devnum) < 0 || |
| sd_device_get_devname(d, &dn) < 0) |
| continue; |
| |
| r = sd_device_get_property_value(d, "MD_LEVEL", &md_level); |
| if (r < 0) { |
| log_warning_errno(r, "Failed to get MD_LEVEL property for %s, ignoring: %m", dn); |
| continue; |
| } |
| |
| /* MD "containers" are a special type of MD devices, used for external metadata. Since it |
| * doesn't provide RAID functionality in itself we don't need to stop it. */ |
| if (streq(md_level, "container")) |
| continue; |
| |
| p = strdup(dn); |
| if (!p) |
| return -ENOMEM; |
| |
| m = new(MountPoint, 1); |
| if (!m) |
| return -ENOMEM; |
| |
| *m = (MountPoint) { |
| .path = TAKE_PTR(p), |
| .devnum = devnum, |
| }; |
| |
| LIST_PREPEND(mount_point, *head, m); |
| } |
| |
| return 0; |
| } |
| |
| static int delete_loopback(const char *device) { |
| _cleanup_close_ int fd = -EBADF; |
| struct loop_info64 info; |
| |
| assert(device); |
| |
| fd = open(device, O_RDONLY|O_CLOEXEC); |
| if (fd < 0) { |
| log_debug_errno(errno, "Failed to open loopback device %s: %m", device); |
| return errno == ENOENT ? 0 : -errno; |
| } |
| |
| /* Loopback block devices don't sync in-flight blocks when we clear the fd, hence sync explicitly |
| * first */ |
| if (fsync(fd) < 0) |
| log_debug_errno(errno, "Failed to sync loop block device %s, ignoring: %m", device); |
| |
| if (ioctl(fd, LOOP_CLR_FD, 0) < 0) { |
| if (errno == ENXIO) /* Nothing bound, didn't do anything */ |
| return 0; |
| |
| if (errno != EBUSY) |
| return log_debug_errno(errno, "Failed to clear loopback device %s: %m", device); |
| |
| if (ioctl(fd, LOOP_GET_STATUS64, &info) < 0) { |
| if (errno == ENXIO) /* What? Suddenly detached after all? That's fine by us then. */ |
| return 1; |
| |
| log_debug_errno(errno, "Failed to invoke LOOP_GET_STATUS64 on loopback device %s, ignoring: %m", device); |
| return -EBUSY; /* propagate original error */ |
| } |
| |
| #if HAVE_VALGRIND_MEMCHECK_H |
| VALGRIND_MAKE_MEM_DEFINED(&info, sizeof(info)); |
| #endif |
| |
| if (FLAGS_SET(info.lo_flags, LO_FLAGS_AUTOCLEAR)) /* someone else already set LO_FLAGS_AUTOCLEAR for us? fine by us */ |
| return -EBUSY; /* propagate original error */ |
| |
| info.lo_flags |= LO_FLAGS_AUTOCLEAR; |
| if (ioctl(fd, LOOP_SET_STATUS64, &info) < 0) { |
| if (errno == ENXIO) /* Suddenly detached after all? Fine by us */ |
| return 1; |
| |
| log_debug_errno(errno, "Failed to set LO_FLAGS_AUTOCLEAR flag for loop device %s, ignoring: %m", device); |
| } else |
| log_debug("Successfully set LO_FLAGS_AUTOCLEAR flag for loop device %s.", device); |
| |
| return -EBUSY; |
| } |
| |
| if (ioctl(fd, LOOP_GET_STATUS64, &info) < 0) { |
| /* If the LOOP_CLR_FD above succeeded we'll see ENXIO here. */ |
| if (errno == ENXIO) |
| log_debug("Successfully detached loopback device %s.", device); |
| else |
| log_debug_errno(errno, "Failed to invoke LOOP_GET_STATUS64 on loopback device %s, ignoring: %m", device); /* the LOOP_CLR_FD at least worked, let's hope for the best */ |
| |
| return 1; |
| } |
| |
| #if HAVE_VALGRIND_MEMCHECK_H |
| VALGRIND_MAKE_MEM_DEFINED(&info, sizeof(info)); |
| #endif |
| |
| /* Linux makes LOOP_CLR_FD succeed whenever LO_FLAGS_AUTOCLEAR is set without actually doing |
| * anything. Very confusing. Let's hence not claim we did anything in this case. */ |
| if (FLAGS_SET(info.lo_flags, LO_FLAGS_AUTOCLEAR)) |
| log_debug("Successfully called LOOP_CLR_FD on a loopback device %s with autoclear set, which is a NOP.", device); |
| else |
| log_debug("Weird, LOOP_CLR_FD succeeded but the device is still attached on %s.", device); |
| |
| return -EBUSY; /* Nothing changed, the device is still attached, hence it apparently is still busy */ |
| } |
| |
| static int delete_dm(MountPoint *m) { |
| _cleanup_close_ int fd = -EBADF; |
| int r; |
| |
| assert(m); |
| assert(major(m->devnum) != 0); |
| assert(m->path); |
| |
| fd = open("/dev/mapper/control", O_RDWR|O_CLOEXEC); |
| if (fd < 0) |
| return -errno; |
| |
| r = fsync_path_at(AT_FDCWD, m->path); |
| if (r < 0) |
| log_debug_errno(r, "Failed to sync DM block device %s, ignoring: %m", m->path); |
| |
| return RET_NERRNO(ioctl(fd, DM_DEV_REMOVE, &(struct dm_ioctl) { |
| .version = { |
| DM_VERSION_MAJOR, |
| DM_VERSION_MINOR, |
| DM_VERSION_PATCHLEVEL |
| }, |
| .data_size = sizeof(struct dm_ioctl), |
| .dev = m->devnum, |
| })); |
| } |
| |
| static int delete_md(MountPoint *m) { |
| _cleanup_close_ int fd = -EBADF; |
| |
| assert(m); |
| assert(major(m->devnum) != 0); |
| assert(m->path); |
| |
| fd = open(m->path, O_RDONLY|O_CLOEXEC|O_EXCL); |
| if (fd < 0) |
| return -errno; |
| |
| if (fsync(fd) < 0) |
| log_debug_errno(errno, "Failed to sync MD block device %s, ignoring: %m", m->path); |
| |
| return RET_NERRNO(ioctl(fd, STOP_ARRAY, NULL)); |
| } |
| |
| static bool nonunmountable_path(const char *path) { |
| return path_equal(path, "/") |
| #if ! HAVE_SPLIT_USR |
| || path_equal(path, "/usr") |
| #endif |
| || path_startswith(path, "/run/initramfs"); |
| } |
| |
| static void log_umount_blockers(const char *mnt) { |
| _cleanup_free_ char *blockers = NULL; |
| int r; |
| |
| _cleanup_closedir_ DIR *dir = opendir("/proc"); |
| if (!dir) |
| return (void) log_warning_errno(errno, "Failed to open /proc/: %m"); |
| |
| FOREACH_DIRENT_ALL(de, dir, break) { |
| if (!IN_SET(de->d_type, DT_DIR, DT_UNKNOWN)) |
| continue; |
| |
| pid_t pid; |
| if (parse_pid(de->d_name, &pid) < 0) |
| continue; |
| |
| _cleanup_free_ char *fdp = path_join(de->d_name, "fd"); |
| if (!fdp) |
| return (void) log_oom(); |
| |
| _cleanup_closedir_ DIR *fd_dir = xopendirat(dirfd(dir), fdp, 0); |
| if (!fd_dir) { |
| if (errno != ENOENT) /* process gone by now? */ |
| log_debug_errno(errno, "Failed to open /proc/%s/, ignoring: %m",fdp); |
| continue; |
| } |
| |
| bool culprit = false; |
| FOREACH_DIRENT(fd_de, fd_dir, break) { |
| _cleanup_free_ char *open_file = NULL; |
| |
| r = readlinkat_malloc(dirfd(fd_dir), fd_de->d_name, &open_file); |
| if (r < 0) { |
| if (r != -ENOENT) /* fd closed by now */ |
| log_debug_errno(r, "Failed to read link /proc/%s/%s, ignoring: %m", fdp, fd_de->d_name); |
| continue; |
| } |
| |
| if (path_startswith(open_file, mnt)) { |
| culprit = true; |
| break; |
| } |
| } |
| |
| if (!culprit) |
| continue; |
| |
| _cleanup_free_ char *comm = NULL; |
| r = get_process_comm(pid, &comm); |
| if (r < 0) { |
| if (r != -ESRCH) /* process gone by now */ |
| log_debug_errno(r, "Failed to read process name of PID " PID_FMT ": %m", pid); |
| continue; |
| } |
| |
| if (!strextend_with_separator(&blockers, ", ", comm)) |
| return (void) log_oom(); |
| |
| if (!strextend(&blockers, "(", de->d_name, ")")) |
| return (void) log_oom(); |
| } |
| |
| if (blockers) |
| log_warning("Unmounting '%s' blocked by: %s", mnt, blockers); |
| } |
| |
| static int remount_with_timeout(MountPoint *m, bool last_try) { |
| _cleanup_(close_pairp) int pfd[2] = PIPE_EBADF; |
| _cleanup_(sigkill_nowaitp) pid_t pid = 0; |
| int r; |
| |
| BLOCK_SIGNALS(SIGCHLD); |
| |
| assert(m); |
| |
| r = pipe2(pfd, O_CLOEXEC|O_NONBLOCK); |
| if (r < 0) |
| return r; |
| |
| /* Due to the possibility of a remount operation hanging, we fork a child process and set a |
| * timeout. If the timeout lapses, the assumption is that the particular remount failed. */ |
| r = safe_fork_full("(sd-remount)", pfd, ELEMENTSOF(pfd), FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_LOG|FORK_REOPEN_LOG, &pid); |
| if (r < 0) |
| return r; |
| if (r == 0) { |
| pfd[0] = safe_close(pfd[0]); |
| |
| log_info("Remounting '%s' read-only with options '%s'.", m->path, strempty(m->remount_options)); |
| |
| /* Start the mount operation here in the child */ |
| r = mount(NULL, m->path, NULL, m->remount_flags, m->remount_options); |
| if (r < 0) |
| log_full_errno(last_try ? LOG_ERR : LOG_INFO, |
| errno, |
| "Failed to remount '%s' read-only: %m", |
| m->path); |
| |
| (void) write(pfd[1], &r, sizeof(r)); /* try to send errno up */ |
| _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS); |
| } |
| |
| pfd[1] = safe_close(pfd[1]); |
| |
| r = wait_for_terminate_with_timeout(pid, DEFAULT_TIMEOUT_USEC); |
| if (r == -ETIMEDOUT) |
| log_error_errno(r, "Remounting '%s' timed out, issuing SIGKILL to PID " PID_FMT ".", m->path, pid); |
| else if (r == -EPROTO) { |
| /* Try to read error code from child */ |
| if (read(pfd[0], &r, sizeof(r)) == sizeof(r)) |
| log_debug_errno(r, "Remounting '%s' failed abnormally, child process " PID_FMT " failed: %m", m->path, pid); |
| else |
| r = log_debug_errno(EPROTO, "Remounting '%s' failed abnormally, child process " PID_FMT " aborted or exited non-zero.", m->path, pid); |
| TAKE_PID(pid); /* child exited (just not as we expected) hence don't kill anymore */ |
| } else if (r < 0) |
| log_error_errno(r, "Remounting '%s' failed unexpectedly, couldn't wait for child process " PID_FMT ": %m", m->path, pid); |
| |
| return r; |
| } |
| |
| static int umount_with_timeout(MountPoint *m, bool last_try) { |
| _cleanup_(close_pairp) int pfd[2] = PIPE_EBADF; |
| _cleanup_(sigkill_nowaitp) pid_t pid = 0; |
| int r; |
| |
| BLOCK_SIGNALS(SIGCHLD); |
| |
| assert(m); |
| |
| r = pipe2(pfd, O_CLOEXEC|O_NONBLOCK); |
| if (r < 0) |
| return r; |
| |
| /* Due to the possibility of a umount operation hanging, we fork a child process and set a |
| * timeout. If the timeout lapses, the assumption is that the particular umount failed. */ |
| r = safe_fork_full("(sd-umount)", pfd, ELEMENTSOF(pfd), FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_LOG|FORK_REOPEN_LOG, &pid); |
| if (r < 0) |
| return r; |
| if (r == 0) { |
| pfd[0] = safe_close(pfd[0]); |
| |
| log_info("Unmounting '%s'.", m->path); |
| |
| /* Start the mount operation here in the child Using MNT_FORCE causes some filesystems |
| * (e.g. FUSE and NFS and other network filesystems) to abort any pending requests and return |
| * -EIO rather than blocking indefinitely. If the filesysten is "busy", this may allow |
| * processes to die, thus making the filesystem less busy so the unmount might succeed |
| * (rather than return EBUSY). */ |
| r = RET_NERRNO(umount2(m->path, |
| UMOUNT_NOFOLLOW | /* Don't follow symlinks: this should never happen unless our mount list was wrong */ |
| (m->umount_lazily ? MNT_DETACH : MNT_FORCE))); |
| if (r < 0) { |
| log_full_errno(last_try ? LOG_ERR : LOG_INFO, r, "Failed to unmount %s: %m", m->path); |
| |
| if (r == -EBUSY && last_try) |
| log_umount_blockers(m->path); |
| } |
| |
| (void) write(pfd[1], &r, sizeof(r)); /* try to send errno up */ |
| _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS); |
| } |
| |
| pfd[1] = safe_close(pfd[1]); |
| |
| r = wait_for_terminate_with_timeout(pid, DEFAULT_TIMEOUT_USEC); |
| if (r == -ETIMEDOUT) |
| log_error_errno(r, "Unmounting '%s' timed out, issuing SIGKILL to PID " PID_FMT ".", m->path, pid); |
| else if (r == -EPROTO) { |
| /* Try to read error code from child */ |
| if (read(pfd[0], &r, sizeof(r)) == sizeof(r)) |
| log_debug_errno(r, "Unmounting '%s' failed abnormally, child process " PID_FMT " failed: %m", m->path, pid); |
| else |
| r = log_debug_errno(EPROTO, "Unmounting '%s' failed abnormally, child process " PID_FMT " aborted or exited non-zero.", m->path, pid); |
| TAKE_PID(pid); /* It died, but abnormally, no purpose in killing */ |
| } else if (r < 0) |
| log_error_errno(r, "Unmounting '%s' failed unexpectedly, couldn't wait for child process " PID_FMT ": %m", m->path, pid); |
| |
| return r; |
| } |
| |
| /* This includes remounting readonly, which changes the kernel mount options. Therefore the list passed to |
| * this function is invalidated, and should not be reused. */ |
| static int mount_points_list_umount(MountPoint **head, bool *changed, bool last_try) { |
| int n_failed = 0, r; |
| _cleanup_free_ char *resolved_mounts_path = NULL; |
| |
| assert(head); |
| assert(changed); |
| |
| LIST_FOREACH(mount_point, m, *head) { |
| if (m->try_remount_ro) { |
| /* 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 somewhere 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 a dirty fs we cannot otherwise see. |
| * |
| * Since the remount can hang in the instance of remote filesystems, we remount |
| * asynchronously and skip the subsequent umount if it fails. */ |
| if (remount_with_timeout(m, last_try) < 0) { |
| /* Remount failed, but try unmounting anyway, |
| * unless this is a mount point we want to skip. */ |
| if (nonunmountable_path(m->path)) { |
| n_failed++; |
| continue; |
| } |
| } |
| } |
| |
| /* Skip / and /usr since we cannot unmount that anyway, since we are running from it. They |
| * have already been remounted ro. */ |
| if (nonunmountable_path(m->path)) |
| continue; |
| |
| /* Trying to umount */ |
| r = umount_with_timeout(m, last_try); |
| if (r < 0) |
| n_failed++; |
| else |
| *changed = true; |
| |
| /* If a mount is busy, we move it to not keep parent mount points busy. |
| * If a mount point is not a leaf, moving it would invalidate our mount table. |
| * More moving will occur in next iteration with a fresh mount table. |
| */ |
| if (r != -EBUSY || !m->leaf) |
| continue; |
| |
| _cleanup_free_ char *dirname = NULL; |
| |
| r = path_extract_directory(m->path, &dirname); |
| if (r < 0) { |
| n_failed++; |
| log_full_errno(last_try ? LOG_ERR : LOG_INFO, r, "Cannot find directory for %s: %m", m->path); |
| continue; |
| } |
| |
| /* We need to canonicalize /run/shutdown/mounts. We cannot compare inodes, since /run |
| * might be bind mounted somewhere we want to unmount. And we need to move all mounts in |
| * /run/shutdown/mounts from there. |
| */ |
| if (!resolved_mounts_path) |
| (void) chase_symlinks("/run/shutdown/mounts", NULL, 0, &resolved_mounts_path, NULL); |
| if (!path_equal(dirname, resolved_mounts_path)) { |
| char newpath[STRLEN("/run/shutdown/mounts/") + 16 + 1]; |
| |
| xsprintf(newpath, "/run/shutdown/mounts/%016" PRIx64, random_u64()); |
| |
| /* on error of is_dir, assume directory */ |
| if (is_dir(m->path, true) != 0) { |
| r = mkdir_p(newpath, 0000); |
| if (r < 0) { |
| log_full_errno(last_try ? LOG_ERR : LOG_INFO, r, "Could not create directory %s: %m", newpath); |
| continue; |
| } |
| } else { |
| r = touch_file(newpath, /* parents= */ true, USEC_INFINITY, UID_INVALID, GID_INVALID, 0700); |
| if (r < 0) { |
| log_full_errno(last_try ? LOG_ERR : LOG_INFO, r, "Could not create file %s: %m", newpath); |
| continue; |
| } |
| } |
| |
| log_info("Moving mount %s to %s.", m->path, newpath); |
| |
| r = RET_NERRNO(mount(m->path, newpath, NULL, MS_MOVE, NULL)); |
| if (r < 0) { |
| n_failed++; |
| log_full_errno(last_try ? LOG_ERR : LOG_INFO, r, "Could not move %s to %s: %m", m->path, newpath); |
| } else |
| *changed = true; |
| } |
| } |
| |
| return n_failed; |
| } |
| |
| static int swap_points_list_off(MountPoint **head, bool *changed) { |
| int n_failed = 0; |
| |
| assert(head); |
| assert(changed); |
| |
| LIST_FOREACH(mount_point, m, *head) { |
| log_info("Deactivating swap %s.", m->path); |
| if (swapoff(m->path) < 0) { |
| log_warning_errno(errno, "Could not deactivate swap %s: %m", m->path); |
| n_failed++; |
| continue; |
| } |
| |
| *changed = true; |
| mount_point_free(head, m); |
| } |
| |
| return n_failed; |
| } |
| |
| static int loopback_points_list_detach(MountPoint **head, bool *changed, bool last_try) { |
| int n_failed = 0, r; |
| dev_t rootdev = 0; |
| |
| assert(head); |
| assert(changed); |
| |
| (void) get_block_device("/", &rootdev); |
| |
| LIST_FOREACH(mount_point, m, *head) { |
| if (major(rootdev) != 0 && rootdev == m->devnum) { |
| n_failed++; |
| continue; |
| } |
| |
| log_info("Detaching loopback %s.", m->path); |
| r = delete_loopback(m->path); |
| if (r < 0) { |
| log_full_errno(last_try ? LOG_ERR : LOG_INFO, r, "Could not detach loopback %s: %m", m->path); |
| n_failed++; |
| continue; |
| } |
| if (r > 0) |
| *changed = true; |
| |
| mount_point_free(head, m); |
| } |
| |
| return n_failed; |
| } |
| |
| static int dm_points_list_detach(MountPoint **head, bool *changed, bool last_try) { |
| int n_failed = 0, r; |
| dev_t rootdev = 0; |
| |
| assert(head); |
| assert(changed); |
| |
| (void) get_block_device("/", &rootdev); |
| |
| LIST_FOREACH(mount_point, m, *head) { |
| if (major(rootdev) != 0 && rootdev == m->devnum) { |
| n_failed ++; |
| continue; |
| } |
| |
| log_info("Detaching DM %s (%u:%u).", m->path, major(m->devnum), minor(m->devnum)); |
| r = delete_dm(m); |
| if (r < 0) { |
| log_full_errno(last_try ? LOG_ERR : LOG_INFO, r, "Could not detach DM %s: %m", m->path); |
| n_failed++; |
| continue; |
| } |
| |
| *changed = true; |
| mount_point_free(head, m); |
| } |
| |
| return n_failed; |
| } |
| |
| static int md_points_list_detach(MountPoint **head, bool *changed, bool last_try) { |
| int n_failed = 0, r; |
| dev_t rootdev = 0; |
| |
| assert(head); |
| assert(changed); |
| |
| (void) get_block_device("/", &rootdev); |
| |
| LIST_FOREACH(mount_point, m, *head) { |
| if (major(rootdev) != 0 && rootdev == m->devnum) { |
| n_failed ++; |
| continue; |
| } |
| |
| log_info("Stopping MD %s (%u:%u).", m->path, major(m->devnum), minor(m->devnum)); |
| r = delete_md(m); |
| if (r < 0) { |
| log_full_errno(last_try ? LOG_ERR : LOG_INFO, r, "Could not stop MD %s: %m", m->path); |
| n_failed++; |
| continue; |
| } |
| |
| *changed = true; |
| mount_point_free(head, m); |
| } |
| |
| return n_failed; |
| } |
| |
| static int umount_all_once(bool *changed, bool last_try) { |
| _cleanup_(mount_points_list_free) LIST_HEAD(MountPoint, mp_list_head); |
| int r; |
| |
| assert(changed); |
| |
| LIST_HEAD_INIT(mp_list_head); |
| r = mount_points_list_get(NULL, &mp_list_head); |
| if (r < 0) |
| return r; |
| |
| return mount_points_list_umount(&mp_list_head, changed, last_try); |
| } |
| |
| int umount_all(bool *changed, bool last_try) { |
| bool umount_changed; |
| int r; |
| |
| assert(changed); |
| |
| /* Retry umount, until nothing can be umounted anymore. Mounts are processed in order, newest |
| * first. The retries are needed when an old mount has been moved, to a path inside a newer mount. */ |
| do { |
| umount_changed = false; |
| |
| r = umount_all_once(&umount_changed, last_try); |
| if (umount_changed) |
| *changed = true; |
| } while (umount_changed); |
| |
| return r; |
| } |
| |
| int swapoff_all(bool *changed) { |
| _cleanup_(mount_points_list_free) LIST_HEAD(MountPoint, swap_list_head); |
| int r; |
| |
| assert(changed); |
| |
| LIST_HEAD_INIT(swap_list_head); |
| |
| r = swap_list_get(NULL, &swap_list_head); |
| if (r < 0) |
| return r; |
| |
| return swap_points_list_off(&swap_list_head, changed); |
| } |
| |
| int loopback_detach_all(bool *changed, bool last_try) { |
| _cleanup_(mount_points_list_free) LIST_HEAD(MountPoint, loopback_list_head); |
| int r; |
| |
| assert(changed); |
| |
| LIST_HEAD_INIT(loopback_list_head); |
| |
| r = loopback_list_get(&loopback_list_head); |
| if (r < 0) |
| return r; |
| |
| return loopback_points_list_detach(&loopback_list_head, changed, last_try); |
| } |
| |
| int dm_detach_all(bool *changed, bool last_try) { |
| _cleanup_(mount_points_list_free) LIST_HEAD(MountPoint, dm_list_head); |
| int r; |
| |
| assert(changed); |
| |
| LIST_HEAD_INIT(dm_list_head); |
| |
| r = dm_list_get(&dm_list_head); |
| if (r < 0) |
| return r; |
| |
| return dm_points_list_detach(&dm_list_head, changed, last_try); |
| } |
| |
| int md_detach_all(bool *changed, bool last_try) { |
| _cleanup_(mount_points_list_free) LIST_HEAD(MountPoint, md_list_head); |
| int r; |
| |
| assert(changed); |
| |
| LIST_HEAD_INIT(md_list_head); |
| |
| r = md_list_get(&md_list_head); |
| if (r < 0) |
| return r; |
| |
| return md_points_list_detach(&md_list_head, changed, last_try); |
| } |
