diff options
Diffstat (limited to 'src/core/mount.c')
| -rw-r--r-- | src/core/mount.c | 2043 |
1 files changed, 2043 insertions, 0 deletions
diff --git a/src/core/mount.c b/src/core/mount.c new file mode 100644 index 0000000..c31cad6 --- /dev/null +++ b/src/core/mount.c @@ -0,0 +1,2043 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include <errno.h> +#include <signal.h> +#include <stdio.h> +#include <sys/epoll.h> + +#include <libmount.h> + +#include "sd-messages.h" + +#include "alloc-util.h" +#include "dbus-mount.h" +#include "dbus-unit.h" +#include "device.h" +#include "escape.h" +#include "exit-status.h" +#include "format-util.h" +#include "fstab-util.h" +#include "log.h" +#include "manager.h" +#include "mkdir.h" +#include "mount-setup.h" +#include "mount.h" +#include "mountpoint-util.h" +#include "parse-util.h" +#include "path-util.h" +#include "process-util.h" +#include "serialize.h" +#include "special.h" +#include "string-table.h" +#include "string-util.h" +#include "strv.h" +#include "unit-name.h" +#include "unit.h" + +#define RETRY_UMOUNT_MAX 32 + +DEFINE_TRIVIAL_CLEANUP_FUNC(struct libmnt_table*, mnt_free_table); +DEFINE_TRIVIAL_CLEANUP_FUNC(struct libmnt_iter*, mnt_free_iter); + +static const UnitActiveState state_translation_table[_MOUNT_STATE_MAX] = { + [MOUNT_DEAD] = UNIT_INACTIVE, + [MOUNT_MOUNTING] = UNIT_ACTIVATING, + [MOUNT_MOUNTING_DONE] = UNIT_ACTIVATING, + [MOUNT_MOUNTED] = UNIT_ACTIVE, + [MOUNT_REMOUNTING] = UNIT_RELOADING, + [MOUNT_UNMOUNTING] = UNIT_DEACTIVATING, + [MOUNT_REMOUNTING_SIGTERM] = UNIT_RELOADING, + [MOUNT_REMOUNTING_SIGKILL] = UNIT_RELOADING, + [MOUNT_UNMOUNTING_SIGTERM] = UNIT_DEACTIVATING, + [MOUNT_UNMOUNTING_SIGKILL] = UNIT_DEACTIVATING, + [MOUNT_FAILED] = UNIT_FAILED +}; + +static int mount_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata); +static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata); + +static bool MOUNT_STATE_WITH_PROCESS(MountState state) { + return IN_SET(state, + MOUNT_MOUNTING, + MOUNT_MOUNTING_DONE, + MOUNT_REMOUNTING, + MOUNT_REMOUNTING_SIGTERM, + MOUNT_REMOUNTING_SIGKILL, + MOUNT_UNMOUNTING, + MOUNT_UNMOUNTING_SIGTERM, + MOUNT_UNMOUNTING_SIGKILL); +} + +static bool mount_is_network(const MountParameters *p) { + assert(p); + + if (fstab_test_option(p->options, "_netdev\0")) + return true; + + if (p->fstype && fstype_is_network(p->fstype)) + return true; + + return false; +} + +static bool mount_is_loop(const MountParameters *p) { + assert(p); + + if (fstab_test_option(p->options, "loop\0")) + return true; + + return false; +} + +static bool mount_is_bind(const MountParameters *p) { + assert(p); + + if (fstab_test_option(p->options, "bind\0" "rbind\0")) + return true; + + if (p->fstype && STR_IN_SET(p->fstype, "bind", "rbind")) + return true; + + return false; +} + +static bool mount_is_auto(const MountParameters *p) { + assert(p); + + return !fstab_test_option(p->options, "noauto\0"); +} + +static bool mount_is_automount(const MountParameters *p) { + assert(p); + + return fstab_test_option(p->options, + "comment=systemd.automount\0" + "x-systemd.automount\0"); +} + +static bool mount_is_bound_to_device(const Mount *m) { + const MountParameters *p; + + if (m->from_fragment) + return true; + + p = &m->parameters_proc_self_mountinfo; + return fstab_test_option(p->options, "x-systemd.device-bound\0"); +} + +static bool mount_needs_quota(const MountParameters *p) { + assert(p); + + /* Quotas are not enabled on network filesystems, but we want them, for example, on storage connected via + * iscsi. We hence don't use mount_is_network() here, as that would also return true for _netdev devices. */ + if (p->fstype && fstype_is_network(p->fstype)) + return false; + + if (mount_is_bind(p)) + return false; + + return fstab_test_option(p->options, + "usrquota\0" "grpquota\0" "quota\0" "usrjquota\0" "grpjquota\0"); +} + +static void mount_init(Unit *u) { + Mount *m = MOUNT(u); + + assert(u); + assert(u->load_state == UNIT_STUB); + + m->timeout_usec = u->manager->default_timeout_start_usec; + + m->exec_context.std_output = u->manager->default_std_output; + m->exec_context.std_error = u->manager->default_std_error; + + m->directory_mode = 0755; + + /* We need to make sure that /usr/bin/mount is always called + * in the same process group as us, so that the autofs kernel + * side doesn't send us another mount request while we are + * already trying to comply its last one. */ + m->exec_context.same_pgrp = true; + + m->control_command_id = _MOUNT_EXEC_COMMAND_INVALID; + + u->ignore_on_isolate = true; +} + +static int mount_arm_timer(Mount *m, usec_t usec) { + int r; + + assert(m); + + if (m->timer_event_source) { + r = sd_event_source_set_time(m->timer_event_source, usec); + if (r < 0) + return r; + + return sd_event_source_set_enabled(m->timer_event_source, SD_EVENT_ONESHOT); + } + + if (usec == USEC_INFINITY) + return 0; + + r = sd_event_add_time( + UNIT(m)->manager->event, + &m->timer_event_source, + CLOCK_MONOTONIC, + usec, 0, + mount_dispatch_timer, m); + if (r < 0) + return r; + + (void) sd_event_source_set_description(m->timer_event_source, "mount-timer"); + + return 0; +} + +static void mount_unwatch_control_pid(Mount *m) { + assert(m); + + if (m->control_pid <= 0) + return; + + unit_unwatch_pid(UNIT(m), m->control_pid); + m->control_pid = 0; +} + +static void mount_parameters_done(MountParameters *p) { + assert(p); + + p->what = mfree(p->what); + p->options = mfree(p->options); + p->fstype = mfree(p->fstype); +} + +static void mount_done(Unit *u) { + Mount *m = MOUNT(u); + + assert(m); + + m->where = mfree(m->where); + + mount_parameters_done(&m->parameters_proc_self_mountinfo); + mount_parameters_done(&m->parameters_fragment); + + m->exec_runtime = exec_runtime_unref(m->exec_runtime, false); + exec_command_done_array(m->exec_command, _MOUNT_EXEC_COMMAND_MAX); + m->control_command = NULL; + + dynamic_creds_unref(&m->dynamic_creds); + + mount_unwatch_control_pid(m); + + m->timer_event_source = sd_event_source_unref(m->timer_event_source); +} + +_pure_ static MountParameters* get_mount_parameters_fragment(Mount *m) { + assert(m); + + if (m->from_fragment) + return &m->parameters_fragment; + + return NULL; +} + +_pure_ static MountParameters* get_mount_parameters(Mount *m) { + assert(m); + + if (m->from_proc_self_mountinfo) + return &m->parameters_proc_self_mountinfo; + + return get_mount_parameters_fragment(m); +} + +static int update_parameters_proc_self_mount_info( + Mount *m, + const char *what, + const char *options, + const char *fstype) { + + MountParameters *p; + int r, q, w; + + p = &m->parameters_proc_self_mountinfo; + + r = free_and_strdup(&p->what, what); + if (r < 0) + return r; + + q = free_and_strdup(&p->options, options); + if (q < 0) + return q; + + w = free_and_strdup(&p->fstype, fstype); + if (w < 0) + return w; + + return r > 0 || q > 0 || w > 0; +} + +static int mount_add_mount_dependencies(Mount *m) { + MountParameters *pm; + Unit *other; + Iterator i; + Set *s; + int r; + + assert(m); + + if (!path_equal(m->where, "/")) { + _cleanup_free_ char *parent = NULL; + + /* Adds in links to other mount points that might lie further up in the hierarchy */ + + parent = dirname_malloc(m->where); + if (!parent) + return -ENOMEM; + + r = unit_require_mounts_for(UNIT(m), parent, UNIT_DEPENDENCY_IMPLICIT); + if (r < 0) + return r; + } + + /* Adds in dependencies to other mount points that might be needed for the source path (if this is a bind mount + * or a loop mount) to be available. */ + pm = get_mount_parameters_fragment(m); + if (pm && pm->what && + path_is_absolute(pm->what) && + (mount_is_bind(pm) || mount_is_loop(pm) || !mount_is_network(pm))) { + + r = unit_require_mounts_for(UNIT(m), pm->what, UNIT_DEPENDENCY_FILE); + if (r < 0) + return r; + } + + /* Adds in dependencies to other units that use this path or paths further down in the hierarchy */ + s = manager_get_units_requiring_mounts_for(UNIT(m)->manager, m->where); + SET_FOREACH(other, s, i) { + + if (other->load_state != UNIT_LOADED) + continue; + + if (other == UNIT(m)) + continue; + + r = unit_add_dependency(other, UNIT_AFTER, UNIT(m), true, UNIT_DEPENDENCY_PATH); + if (r < 0) + return r; + + if (UNIT(m)->fragment_path) { + /* If we have fragment configuration, then make this dependency required */ + r = unit_add_dependency(other, UNIT_REQUIRES, UNIT(m), true, UNIT_DEPENDENCY_PATH); + if (r < 0) + return r; + } + } + + return 0; +} + +static int mount_add_device_dependencies(Mount *m) { + bool device_wants_mount; + UnitDependencyMask mask; + MountParameters *p; + UnitDependency dep; + int r; + + assert(m); + + p = get_mount_parameters(m); + if (!p) + return 0; + + if (!p->what) + return 0; + + if (mount_is_bind(p)) + return 0; + + if (!is_device_path(p->what)) + return 0; + + /* /dev/root is a really weird thing, it's not a real device, + * but just a path the kernel exports for the root file system + * specified on the kernel command line. Ignore it here. */ + if (path_equal(p->what, "/dev/root")) + return 0; + + if (path_equal(m->where, "/")) + return 0; + + device_wants_mount = + mount_is_auto(p) && !mount_is_automount(p) && MANAGER_IS_SYSTEM(UNIT(m)->manager); + + /* Mount units from /proc/self/mountinfo are not bound to devices + * by default since they're subject to races when devices are + * unplugged. But the user can still force this dep with an + * appropriate option (or udev property) so the mount units are + * automatically stopped when the device disappears suddenly. */ + dep = mount_is_bound_to_device(m) ? UNIT_BINDS_TO : UNIT_REQUIRES; + + /* We always use 'what' from /proc/self/mountinfo if mounted */ + mask = m->from_proc_self_mountinfo ? UNIT_DEPENDENCY_MOUNTINFO_IMPLICIT : UNIT_DEPENDENCY_FILE; + + r = unit_add_node_dependency(UNIT(m), p->what, device_wants_mount, dep, mask); + if (r < 0) + return r; + + return 0; +} + +static int mount_add_quota_dependencies(Mount *m) { + UnitDependencyMask mask; + MountParameters *p; + int r; + + assert(m); + + if (!MANAGER_IS_SYSTEM(UNIT(m)->manager)) + return 0; + + p = get_mount_parameters_fragment(m); + if (!p) + return 0; + + if (!mount_needs_quota(p)) + return 0; + + mask = m->from_fragment ? UNIT_DEPENDENCY_FILE : UNIT_DEPENDENCY_MOUNTINFO_IMPLICIT; + + r = unit_add_two_dependencies_by_name(UNIT(m), UNIT_BEFORE, UNIT_WANTS, SPECIAL_QUOTACHECK_SERVICE, true, mask); + if (r < 0) + return r; + + r = unit_add_two_dependencies_by_name(UNIT(m), UNIT_BEFORE, UNIT_WANTS, SPECIAL_QUOTAON_SERVICE, true, mask); + if (r < 0) + return r; + + return 0; +} + +static bool mount_is_extrinsic(Mount *m) { + MountParameters *p; + assert(m); + + /* Returns true for all units that are "magic" and should be excluded from the usual start-up and shutdown + * dependencies. We call them "extrinsic" here, as they are generally mounted outside of the systemd dependency + * logic. We shouldn't attempt to manage them ourselves but it's fine if the user operates on them with us. */ + + if (!MANAGER_IS_SYSTEM(UNIT(m)->manager)) /* We only automatically manage mounts if we are in system mode */ + return true; + + if (PATH_IN_SET(m->where, /* Don't bother with the OS data itself */ + "/", + "/usr")) + return true; + + if (PATH_STARTSWITH_SET(m->where, + "/run/initramfs", /* This should stay around from before we boot until after we shutdown */ + "/proc", /* All of this is API VFS */ + "/sys", /* … dito … */ + "/dev")) /* … dito … */ + return true; + + /* If this is an initrd mount, and we are not in the initrd, then leave this around forever, too. */ + p = get_mount_parameters(m); + if (p && fstab_test_option(p->options, "x-initrd.mount\0") && !in_initrd()) + return true; + + return false; +} + +static int mount_add_default_dependencies(Mount *m) { + const char *after, *before; + UnitDependencyMask mask; + MountParameters *p; + bool nofail; + int r; + + assert(m); + + if (!UNIT(m)->default_dependencies) + return 0; + + /* We do not add any default dependencies to /, /usr or /run/initramfs/, since they are guaranteed to stay + * mounted the whole time, since our system is on it. Also, don't bother with anything mounted below virtual + * file systems, it's also going to be virtual, and hence not worth the effort. */ + if (mount_is_extrinsic(m)) + return 0; + + p = get_mount_parameters(m); + if (!p) + return 0; + + mask = m->from_fragment ? UNIT_DEPENDENCY_FILE : UNIT_DEPENDENCY_MOUNTINFO_DEFAULT; + nofail = m->from_fragment ? fstab_test_yes_no_option(m->parameters_fragment.options, "nofail\0" "fail\0") : false; + + if (mount_is_network(p)) { + /* We order ourselves after network.target. This is + * primarily useful at shutdown: services that take + * down the network should order themselves before + * network.target, so that they are shut down only + * after this mount unit is stopped. */ + + r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, SPECIAL_NETWORK_TARGET, true, mask); + if (r < 0) + return r; + + /* We pull in network-online.target, and order + * ourselves after it. This is useful at start-up to + * actively pull in tools that want to be started + * before we start mounting network file systems, and + * whose purpose it is to delay this until the network + * is "up". */ + + r = unit_add_two_dependencies_by_name(UNIT(m), UNIT_WANTS, UNIT_AFTER, SPECIAL_NETWORK_ONLINE_TARGET, true, mask); + if (r < 0) + return r; + + after = SPECIAL_REMOTE_FS_PRE_TARGET; + before = SPECIAL_REMOTE_FS_TARGET; + } else { + after = SPECIAL_LOCAL_FS_PRE_TARGET; + before = SPECIAL_LOCAL_FS_TARGET; + } + + if (!nofail) { + r = unit_add_dependency_by_name(UNIT(m), UNIT_BEFORE, before, true, mask); + if (r < 0) + return r; + } + + r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, after, true, mask); + if (r < 0) + return r; + + r = unit_add_two_dependencies_by_name(UNIT(m), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, true, mask); + if (r < 0) + return r; + + /* If this is a tmpfs mount then we have to unmount it before we try to deactivate swaps */ + if (streq_ptr(p->fstype, "tmpfs")) { + r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, SPECIAL_SWAP_TARGET, true, mask); + if (r < 0) + return r; + } + + return 0; +} + +static int mount_verify(Mount *m) { + _cleanup_free_ char *e = NULL; + MountParameters *p; + int r; + + assert(m); + + if (UNIT(m)->load_state != UNIT_LOADED) + return 0; + + if (!m->from_fragment && !m->from_proc_self_mountinfo && !UNIT(m)->perpetual) + return -ENOENT; + + r = unit_name_from_path(m->where, ".mount", &e); + if (r < 0) + return log_unit_error_errno(UNIT(m), r, "Failed to generate unit name from mount path: %m"); + + if (!unit_has_name(UNIT(m), e)) { + log_unit_error(UNIT(m), "Where= setting doesn't match unit name. Refusing."); + return -ENOEXEC; + } + + if (mount_point_is_api(m->where) || mount_point_ignore(m->where)) { + log_unit_error(UNIT(m), "Cannot create mount unit for API file system %s. Refusing.", m->where); + return -ENOEXEC; + } + + p = get_mount_parameters_fragment(m); + if (p && !p->what) { + log_unit_error(UNIT(m), "What= setting is missing. Refusing."); + return -ENOEXEC; + } + + if (m->exec_context.pam_name && m->kill_context.kill_mode != KILL_CONTROL_GROUP) { + log_unit_error(UNIT(m), "Unit has PAM enabled. Kill mode must be set to control-group'. Refusing."); + return -ENOEXEC; + } + + return 0; +} + +static int mount_add_extras(Mount *m) { + Unit *u = UNIT(m); + int r; + + assert(m); + + /* Note: this call might be called after we already have been loaded once (and even when it has already been + * activated), in case data from /proc/self/mountinfo has changed. This means all code here needs to be ready + * to run with an already set up unit. */ + + if (u->fragment_path) + m->from_fragment = true; + + if (!m->where) { + r = unit_name_to_path(u->id, &m->where); + if (r < 0) + return r; + } + + path_simplify(m->where, false); + + if (!u->description) { + r = unit_set_description(u, m->where); + if (r < 0) + return r; + } + + r = mount_add_device_dependencies(m); + if (r < 0) + return r; + + r = mount_add_mount_dependencies(m); + if (r < 0) + return r; + + r = mount_add_quota_dependencies(m); + if (r < 0) + return r; + + r = unit_patch_contexts(u); + if (r < 0) + return r; + + r = unit_add_exec_dependencies(u, &m->exec_context); + if (r < 0) + return r; + + r = unit_set_default_slice(u); + if (r < 0) + return r; + + r = mount_add_default_dependencies(m); + if (r < 0) + return r; + + return 0; +} + +static int mount_load_root_mount(Unit *u) { + assert(u); + + if (!unit_has_name(u, SPECIAL_ROOT_MOUNT)) + return 0; + + u->perpetual = true; + u->default_dependencies = false; + + /* The stdio/kmsg bridge socket is on /, in order to avoid a dep loop, don't use kmsg logging for -.mount */ + MOUNT(u)->exec_context.std_output = EXEC_OUTPUT_NULL; + MOUNT(u)->exec_context.std_input = EXEC_INPUT_NULL; + + if (!u->description) + u->description = strdup("Root Mount"); + + return 1; +} + +static int mount_load(Unit *u) { + Mount *m = MOUNT(u); + int r, q, w; + + assert(u); + assert(u->load_state == UNIT_STUB); + + r = mount_load_root_mount(u); + + if (m->from_proc_self_mountinfo || u->perpetual) + q = unit_load_fragment_and_dropin_optional(u); + else + q = unit_load_fragment_and_dropin(u); + + /* Add in some extras. Note we do this in all cases (even if we failed to load the unit) when announced by the + * kernel, because we need some things to be set up no matter what when the kernel establishes a mount and thus + * we need to update the state in our unit to track it. After all, consider that we don't allow changing the + * 'slice' field for a unit once it is active. */ + if (u->load_state == UNIT_LOADED || m->from_proc_self_mountinfo || u->perpetual) + w = mount_add_extras(m); + else + w = 0; + + if (r < 0) + return r; + if (q < 0) + return q; + if (w < 0) + return w; + + return mount_verify(m); +} + +static void mount_set_state(Mount *m, MountState state) { + MountState old_state; + assert(m); + + if (m->state != state) + bus_unit_send_pending_change_signal(UNIT(m), false); + + old_state = m->state; + m->state = state; + + if (!MOUNT_STATE_WITH_PROCESS(state)) { + m->timer_event_source = sd_event_source_unref(m->timer_event_source); + mount_unwatch_control_pid(m); + m->control_command = NULL; + m->control_command_id = _MOUNT_EXEC_COMMAND_INVALID; + } + + if (state != old_state) + log_unit_debug(UNIT(m), "Changed %s -> %s", mount_state_to_string(old_state), mount_state_to_string(state)); + + unit_notify(UNIT(m), state_translation_table[old_state], state_translation_table[state], + m->reload_result == MOUNT_SUCCESS ? 0 : UNIT_NOTIFY_RELOAD_FAILURE); +} + +static int mount_coldplug(Unit *u) { + Mount *m = MOUNT(u); + MountState new_state = MOUNT_DEAD; + int r; + + assert(m); + assert(m->state == MOUNT_DEAD); + + if (m->deserialized_state != m->state) + new_state = m->deserialized_state; + else if (m->from_proc_self_mountinfo) + new_state = MOUNT_MOUNTED; + + if (new_state == m->state) + return 0; + + if (m->control_pid > 0 && + pid_is_unwaited(m->control_pid) && + MOUNT_STATE_WITH_PROCESS(new_state)) { + + r = unit_watch_pid(UNIT(m), m->control_pid); + if (r < 0) + return r; + + r = mount_arm_timer(m, usec_add(u->state_change_timestamp.monotonic, m->timeout_usec)); + if (r < 0) + return r; + } + + if (!IN_SET(new_state, MOUNT_DEAD, MOUNT_FAILED)) { + (void) unit_setup_dynamic_creds(u); + (void) unit_setup_exec_runtime(u); + } + + mount_set_state(m, new_state); + return 0; +} + +static void mount_dump(Unit *u, FILE *f, const char *prefix) { + char buf[FORMAT_TIMESPAN_MAX]; + Mount *m = MOUNT(u); + MountParameters *p; + + assert(m); + assert(f); + + p = get_mount_parameters(m); + + fprintf(f, + "%sMount State: %s\n" + "%sResult: %s\n" + "%sWhere: %s\n" + "%sWhat: %s\n" + "%sFile System Type: %s\n" + "%sOptions: %s\n" + "%sFrom /proc/self/mountinfo: %s\n" + "%sFrom fragment: %s\n" + "%sExtrinsic: %s\n" + "%sDirectoryMode: %04o\n" + "%sSloppyOptions: %s\n" + "%sLazyUnmount: %s\n" + "%sForceUnmount: %s\n" + "%sTimeoutSec: %s\n", + prefix, mount_state_to_string(m->state), + prefix, mount_result_to_string(m->result), + prefix, m->where, + prefix, p ? strna(p->what) : "n/a", + prefix, p ? strna(p->fstype) : "n/a", + prefix, p ? strna(p->options) : "n/a", + prefix, yes_no(m->from_proc_self_mountinfo), + prefix, yes_no(m->from_fragment), + prefix, yes_no(mount_is_extrinsic(m)), + prefix, m->directory_mode, + prefix, yes_no(m->sloppy_options), + prefix, yes_no(m->lazy_unmount), + prefix, yes_no(m->force_unmount), + prefix, format_timespan(buf, sizeof(buf), m->timeout_usec, USEC_PER_SEC)); + + if (m->control_pid > 0) + fprintf(f, + "%sControl PID: "PID_FMT"\n", + prefix, m->control_pid); + + exec_context_dump(&m->exec_context, f, prefix); + kill_context_dump(&m->kill_context, f, prefix); + cgroup_context_dump(&m->cgroup_context, f, prefix); +} + +static int mount_spawn(Mount *m, ExecCommand *c, pid_t *_pid) { + + _cleanup_(exec_params_clear) ExecParameters exec_params = { + .flags = EXEC_APPLY_SANDBOXING|EXEC_APPLY_CHROOT|EXEC_APPLY_TTY_STDIN, + .stdin_fd = -1, + .stdout_fd = -1, + .stderr_fd = -1, + .exec_fd = -1, + }; + pid_t pid; + int r; + + assert(m); + assert(c); + assert(_pid); + + r = unit_prepare_exec(UNIT(m)); + if (r < 0) + return r; + + r = mount_arm_timer(m, usec_add(now(CLOCK_MONOTONIC), m->timeout_usec)); + if (r < 0) + return r; + + r = unit_set_exec_params(UNIT(m), &exec_params); + if (r < 0) + return r; + + r = exec_spawn(UNIT(m), + c, + &m->exec_context, + &exec_params, + m->exec_runtime, + &m->dynamic_creds, + &pid); + if (r < 0) + return r; + + r = unit_watch_pid(UNIT(m), pid); + if (r < 0) + /* FIXME: we need to do something here */ + return r; + + *_pid = pid; + + return 0; +} + +static void mount_enter_dead(Mount *m, MountResult f) { + assert(m); + + if (m->result == MOUNT_SUCCESS) + m->result = f; + + unit_log_result(UNIT(m), m->result == MOUNT_SUCCESS, mount_result_to_string(m->result)); + mount_set_state(m, m->result != MOUNT_SUCCESS ? MOUNT_FAILED : MOUNT_DEAD); + + m->exec_runtime = exec_runtime_unref(m->exec_runtime, true); + + exec_context_destroy_runtime_directory(&m->exec_context, UNIT(m)->manager->prefix[EXEC_DIRECTORY_RUNTIME]); + + unit_unref_uid_gid(UNIT(m), true); + + dynamic_creds_destroy(&m->dynamic_creds); + + /* Any dependencies based on /proc/self/mountinfo are now stale */ + unit_remove_dependencies(UNIT(m), UNIT_DEPENDENCY_MOUNTINFO_IMPLICIT); +} + +static void mount_enter_mounted(Mount *m, MountResult f) { + assert(m); + + if (m->result == MOUNT_SUCCESS) + m->result = f; + + mount_set_state(m, MOUNT_MOUNTED); +} + +static void mount_enter_dead_or_mounted(Mount *m, MountResult f) { + assert(m); + + /* Enter DEAD or MOUNTED state, depending on what the kernel currently says about the mount point. We use this + * whenever we executed an operation, so that our internal state reflects what the kernel says again, after all + * ultimately we just mirror the kernel's internal state on this. */ + + if (m->from_proc_self_mountinfo) + mount_enter_mounted(m, f); + else + mount_enter_dead(m, f); +} + +static int state_to_kill_operation(MountState state) { + switch (state) { + + case MOUNT_REMOUNTING_SIGTERM: + case MOUNT_UNMOUNTING_SIGTERM: + return KILL_TERMINATE; + + case MOUNT_REMOUNTING_SIGKILL: + case MOUNT_UNMOUNTING_SIGKILL: + return KILL_KILL; + + default: + return _KILL_OPERATION_INVALID; + } +} + +static void mount_enter_signal(Mount *m, MountState state, MountResult f) { + int r; + + assert(m); + + if (m->result == MOUNT_SUCCESS) + m->result = f; + + r = unit_kill_context( + UNIT(m), + &m->kill_context, + state_to_kill_operation(state), + -1, + m->control_pid, + false); + if (r < 0) + goto fail; + + if (r > 0) { + r = mount_arm_timer(m, usec_add(now(CLOCK_MONOTONIC), m->timeout_usec)); + if (r < 0) + goto fail; + + mount_set_state(m, state); + } else if (state == MOUNT_REMOUNTING_SIGTERM && m->kill_context.send_sigkill) + mount_enter_signal(m, MOUNT_REMOUNTING_SIGKILL, MOUNT_SUCCESS); + else if (IN_SET(state, MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL)) + mount_enter_mounted(m, MOUNT_SUCCESS); + else if (state == MOUNT_UNMOUNTING_SIGTERM && m->kill_context.send_sigkill) + mount_enter_signal(m, MOUNT_UNMOUNTING_SIGKILL, MOUNT_SUCCESS); + else + mount_enter_dead_or_mounted(m, MOUNT_SUCCESS); + + return; + +fail: + log_unit_warning_errno(UNIT(m), r, "Failed to kill processes: %m"); + mount_enter_dead_or_mounted(m, MOUNT_FAILURE_RESOURCES); +} + +static void mount_enter_unmounting(Mount *m) { + int r; + + assert(m); + + /* Start counting our attempts */ + if (!IN_SET(m->state, + MOUNT_UNMOUNTING, + MOUNT_UNMOUNTING_SIGTERM, + MOUNT_UNMOUNTING_SIGKILL)) + m->n_retry_umount = 0; + + m->control_command_id = MOUNT_EXEC_UNMOUNT; + m->control_command = m->exec_command + MOUNT_EXEC_UNMOUNT; + + r = exec_command_set(m->control_command, UMOUNT_PATH, m->where, "-c", NULL); + if (r >= 0 && m->lazy_unmount) + r = exec_command_append(m->control_command, "-l", NULL); + if (r >= 0 && m->force_unmount) + r = exec_command_append(m->control_command, "-f", NULL); + if (r < 0) + goto fail; + + mount_unwatch_control_pid(m); + + r = mount_spawn(m, m->control_command, &m->control_pid); + if (r < 0) + goto fail; + + mount_set_state(m, MOUNT_UNMOUNTING); + + return; + +fail: + log_unit_warning_errno(UNIT(m), r, "Failed to run 'umount' task: %m"); + mount_enter_dead_or_mounted(m, MOUNT_FAILURE_RESOURCES); +} + +static void mount_enter_mounting(Mount *m) { + int r; + MountParameters *p; + + assert(m); + + r = unit_fail_if_noncanonical(UNIT(m), m->where); + if (r < 0) + goto fail; + + (void) mkdir_p_label(m->where, m->directory_mode); + + unit_warn_if_dir_nonempty(UNIT(m), m->where); + unit_warn_leftover_processes(UNIT(m)); + + m->control_command_id = MOUNT_EXEC_MOUNT; + m->control_command = m->exec_command + MOUNT_EXEC_MOUNT; + + /* Create the source directory for bind-mounts if needed */ + p = get_mount_parameters_fragment(m); + if (p && mount_is_bind(p)) + (void) mkdir_p_label(p->what, m->directory_mode); + + if (p) { + _cleanup_free_ char *opts = NULL; + + r = fstab_filter_options(p->options, "nofail\0" "noauto\0" "auto\0", NULL, NULL, &opts); + if (r < 0) + goto fail; + + r = exec_command_set(m->control_command, MOUNT_PATH, p->what, m->where, NULL); + if (r >= 0 && m->sloppy_options) + r = exec_command_append(m->control_command, "-s", NULL); + if (r >= 0 && p->fstype) + r = exec_command_append(m->control_command, "-t", p->fstype, NULL); + if (r >= 0 && !isempty(opts)) + r = exec_command_append(m->control_command, "-o", opts, NULL); + } else + r = -ENOENT; + if (r < 0) + goto fail; + + mount_unwatch_control_pid(m); + + r = mount_spawn(m, m->control_command, &m->control_pid); + if (r < 0) + goto fail; + + mount_set_state(m, MOUNT_MOUNTING); + + return; + +fail: + log_unit_warning_errno(UNIT(m), r, "Failed to run 'mount' task: %m"); + mount_enter_dead_or_mounted(m, MOUNT_FAILURE_RESOURCES); +} + +static void mount_set_reload_result(Mount *m, MountResult result) { + assert(m); + + /* Only store the first error we encounter */ + if (m->reload_result != MOUNT_SUCCESS) + return; + + m->reload_result = result; +} + +static void mount_enter_remounting(Mount *m) { + int r; + MountParameters *p; + + assert(m); + + /* Reset reload result when we are about to start a new remount operation */ + m->reload_result = MOUNT_SUCCESS; + + m->control_command_id = MOUNT_EXEC_REMOUNT; + m->control_command = m->exec_command + MOUNT_EXEC_REMOUNT; + + p = get_mount_parameters_fragment(m); + if (p) { + const char *o; + + if (p->options) + o = strjoina("remount,", p->options); + else + o = "remount"; + + r = exec_command_set(m->control_command, MOUNT_PATH, + p->what, m->where, + "-o", o, NULL); + if (r >= 0 && m->sloppy_options) + r = exec_command_append(m->control_command, "-s", NULL); + if (r >= 0 && p->fstype) + r = exec_command_append(m->control_command, "-t", p->fstype, NULL); + } else + r = -ENOENT; + if (r < 0) + goto fail; + + mount_unwatch_control_pid(m); + + r = mount_spawn(m, m->control_command, &m->control_pid); + if (r < 0) + goto fail; + + mount_set_state(m, MOUNT_REMOUNTING); + + return; + +fail: + log_unit_warning_errno(UNIT(m), r, "Failed to run 'remount' task: %m"); + mount_set_reload_result(m, MOUNT_FAILURE_RESOURCES); + mount_enter_dead_or_mounted(m, MOUNT_SUCCESS); +} + +static void mount_cycle_clear(Mount *m) { + assert(m); + + /* Clear all state we shall forget for this new cycle */ + + m->result = MOUNT_SUCCESS; + m->reload_result = MOUNT_SUCCESS; + exec_command_reset_status_array(m->exec_command, _MOUNT_EXEC_COMMAND_MAX); + UNIT(m)->reset_accounting = true; +} + +static int mount_start(Unit *u) { + Mount *m = MOUNT(u); + int r; + + assert(m); + + /* We cannot fulfill this request right now, try again later + * please! */ + if (IN_SET(m->state, + MOUNT_UNMOUNTING, + MOUNT_UNMOUNTING_SIGTERM, + MOUNT_UNMOUNTING_SIGKILL)) + return -EAGAIN; + + /* Already on it! */ + if (m->state == MOUNT_MOUNTING) + return 0; + + assert(IN_SET(m->state, MOUNT_DEAD, MOUNT_FAILED)); + + r = unit_start_limit_test(u); + if (r < 0) { + mount_enter_dead(m, MOUNT_FAILURE_START_LIMIT_HIT); + return r; + } + + r = unit_acquire_invocation_id(u); + if (r < 0) + return r; + + mount_cycle_clear(m); + mount_enter_mounting(m); + + return 1; +} + +static int mount_stop(Unit *u) { + Mount *m = MOUNT(u); + + assert(m); + + switch (m->state) { + + case MOUNT_UNMOUNTING: + case MOUNT_UNMOUNTING_SIGKILL: + case MOUNT_UNMOUNTING_SIGTERM: + /* Already on it */ + return 0; + + case MOUNT_MOUNTING: + case MOUNT_MOUNTING_DONE: + case MOUNT_REMOUNTING: + /* If we are still waiting for /bin/mount, we go directly into kill mode. */ + mount_enter_signal(m, MOUNT_UNMOUNTING_SIGTERM, MOUNT_SUCCESS); + return 0; + + case MOUNT_REMOUNTING_SIGTERM: + /* If we are already waiting for a hung remount, convert this to the matching unmounting state */ + mount_set_state(m, MOUNT_UNMOUNTING_SIGTERM); + return 0; + + case MOUNT_REMOUNTING_SIGKILL: + /* as above */ + mount_set_state(m, MOUNT_UNMOUNTING_SIGKILL); + return 0; + + case MOUNT_MOUNTED: + mount_enter_unmounting(m); + return 1; + + default: + assert_not_reached("Unexpected state."); + } +} + +static int mount_reload(Unit *u) { + Mount *m = MOUNT(u); + + assert(m); + assert(m->state == MOUNT_MOUNTED); + + mount_enter_remounting(m); + + return 1; +} + +static int mount_serialize(Unit *u, FILE *f, FDSet *fds) { + Mount *m = MOUNT(u); + + assert(m); + assert(f); + assert(fds); + + (void) serialize_item(f, "state", mount_state_to_string(m->state)); + (void) serialize_item(f, "result", mount_result_to_string(m->result)); + (void) serialize_item(f, "reload-result", mount_result_to_string(m->reload_result)); + (void) serialize_item_format(f, "n-retry-umount", "%u", m->n_retry_umount); + + if (m->control_pid > 0) + (void) serialize_item_format(f, "control-pid", PID_FMT, m->control_pid); + + if (m->control_command_id >= 0) + (void) serialize_item(f, "control-command", mount_exec_command_to_string(m->control_command_id)); + + return 0; +} + +static int mount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) { + Mount *m = MOUNT(u); + int r; + + assert(u); + assert(key); + assert(value); + assert(fds); + + if (streq(key, "state")) { + MountState state; + + if ((state = mount_state_from_string(value)) < 0) + log_unit_debug(u, "Failed to parse state value: %s", value); + else + m->deserialized_state = state; + + } else if (streq(key, "result")) { + MountResult f; + + f = mount_result_from_string(value); + if (f < 0) + log_unit_debug(u, "Failed to parse result value: %s", value); + else if (f != MOUNT_SUCCESS) + m->result = f; + + } else if (streq(key, "reload-result")) { + MountResult f; + + f = mount_result_from_string(value); + if (f < 0) + log_unit_debug(u, "Failed to parse reload result value: %s", value); + else if (f != MOUNT_SUCCESS) + m->reload_result = f; + + } else if (streq(key, "n-retry-umount")) { + + r = safe_atou(value, &m->n_retry_umount); + if (r < 0) + log_unit_debug(u, "Failed to parse n-retry-umount value: %s", value); + + } else if (streq(key, "control-pid")) { + + if (parse_pid(value, &m->control_pid) < 0) + log_unit_debug(u, "Failed to parse control-pid value: %s", value); + + } else if (streq(key, "control-command")) { + MountExecCommand id; + + id = mount_exec_command_from_string(value); + if (id < 0) + log_unit_debug(u, "Failed to parse exec-command value: %s", value); + else { + m->control_command_id = id; + m->control_command = m->exec_command + id; + } + } else + log_unit_debug(u, "Unknown serialization key: %s", key); + + return 0; +} + +_pure_ static UnitActiveState mount_active_state(Unit *u) { + assert(u); + + return state_translation_table[MOUNT(u)->state]; +} + +_pure_ static const char *mount_sub_state_to_string(Unit *u) { + assert(u); + + return mount_state_to_string(MOUNT(u)->state); +} + +_pure_ static bool mount_may_gc(Unit *u) { + Mount *m = MOUNT(u); + + assert(m); + + if (m->from_proc_self_mountinfo) + return false; + + return true; +} + +static void mount_sigchld_event(Unit *u, pid_t pid, int code, int status) { + Mount *m = MOUNT(u); + MountResult f; + + assert(m); + assert(pid >= 0); + + if (pid != m->control_pid) + return; + + m->control_pid = 0; + + if (is_clean_exit(code, status, EXIT_CLEAN_COMMAND, NULL)) + f = MOUNT_SUCCESS; + else if (code == CLD_EXITED) + f = MOUNT_FAILURE_EXIT_CODE; + else if (code == CLD_KILLED) + f = MOUNT_FAILURE_SIGNAL; + else if (code == CLD_DUMPED) + f = MOUNT_FAILURE_CORE_DUMP; + else + assert_not_reached("Unknown code"); + + if (IN_SET(m->state, MOUNT_REMOUNTING, MOUNT_REMOUNTING_SIGKILL, MOUNT_REMOUNTING_SIGTERM)) + mount_set_reload_result(m, f); + else if (m->result == MOUNT_SUCCESS) + m->result = f; + + if (m->control_command) { + exec_status_exit(&m->control_command->exec_status, &m->exec_context, pid, code, status); + + m->control_command = NULL; + m->control_command_id = _MOUNT_EXEC_COMMAND_INVALID; + } + + unit_log_process_exit( + u, f == MOUNT_SUCCESS ? LOG_DEBUG : LOG_NOTICE, + "Mount process", + mount_exec_command_to_string(m->control_command_id), + code, status); + + /* Note that due to the io event priority logic, we can be sure the new mountinfo is loaded + * before we process the SIGCHLD for the mount command. */ + + switch (m->state) { + + case MOUNT_MOUNTING: + /* Our mount point has not appeared in mountinfo. Something went wrong. */ + + if (f == MOUNT_SUCCESS) { + /* Either /bin/mount has an unexpected definition of success, + * or someone raced us and we lost. */ + log_unit_warning(UNIT(m), "Mount process finished, but there is no mount."); + f = MOUNT_FAILURE_PROTOCOL; + } + mount_enter_dead(m, f); + break; + + case MOUNT_MOUNTING_DONE: + mount_enter_mounted(m, f); + break; + + case MOUNT_REMOUNTING: + case MOUNT_REMOUNTING_SIGTERM: + case MOUNT_REMOUNTING_SIGKILL: + mount_enter_dead_or_mounted(m, MOUNT_SUCCESS); + break; + + case MOUNT_UNMOUNTING: + + if (f == MOUNT_SUCCESS && m->from_proc_self_mountinfo) { + + /* Still a mount point? If so, let's try again. Most likely there were multiple mount points + * stacked on top of each other. We might exceed the timeout specified by the user overall, + * but we will stop as soon as any one umount times out. */ + + if (m->n_retry_umount < RETRY_UMOUNT_MAX) { + log_unit_debug(u, "Mount still present, trying again."); + m->n_retry_umount++; + mount_enter_unmounting(m); + } else { + log_unit_warning(u, "Mount still present after %u attempts to unmount, giving up.", m->n_retry_umount); + mount_enter_mounted(m, f); + } + } else + mount_enter_dead_or_mounted(m, f); + + break; + + case MOUNT_UNMOUNTING_SIGKILL: + case MOUNT_UNMOUNTING_SIGTERM: + mount_enter_dead_or_mounted(m, f); + break; + + default: + assert_not_reached("Uh, control process died at wrong time."); + } + + /* Notify clients about changed exit status */ + unit_add_to_dbus_queue(u); +} + +static int mount_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata) { + Mount *m = MOUNT(userdata); + + assert(m); + assert(m->timer_event_source == source); + + switch (m->state) { + + case MOUNT_MOUNTING: + case MOUNT_MOUNTING_DONE: + log_unit_warning(UNIT(m), "Mounting timed out. Terminating."); + mount_enter_signal(m, MOUNT_UNMOUNTING_SIGTERM, MOUNT_FAILURE_TIMEOUT); + break; + + case MOUNT_REMOUNTING: + log_unit_warning(UNIT(m), "Remounting timed out. Terminating remount process."); + mount_set_reload_result(m, MOUNT_FAILURE_TIMEOUT); + mount_enter_signal(m, MOUNT_REMOUNTING_SIGTERM, MOUNT_SUCCESS); + break; + + case MOUNT_REMOUNTING_SIGTERM: + mount_set_reload_result(m, MOUNT_FAILURE_TIMEOUT); + + if (m->kill_context.send_sigkill) { + log_unit_warning(UNIT(m), "Remounting timed out. Killing."); + mount_enter_signal(m, MOUNT_REMOUNTING_SIGKILL, MOUNT_SUCCESS); + } else { + log_unit_warning(UNIT(m), "Remounting timed out. Skipping SIGKILL. Ignoring."); + mount_enter_dead_or_mounted(m, MOUNT_SUCCESS); + } + break; + + case MOUNT_REMOUNTING_SIGKILL: + mount_set_reload_result(m, MOUNT_FAILURE_TIMEOUT); + + log_unit_warning(UNIT(m), "Mount process still around after SIGKILL. Ignoring."); + mount_enter_dead_or_mounted(m, MOUNT_SUCCESS); + break; + + case MOUNT_UNMOUNTING: + log_unit_warning(UNIT(m), "Unmounting timed out. Terminating."); + mount_enter_signal(m, MOUNT_UNMOUNTING_SIGTERM, MOUNT_FAILURE_TIMEOUT); + break; + + case MOUNT_UNMOUNTING_SIGTERM: + if (m->kill_context.send_sigkill) { + log_unit_warning(UNIT(m), "Mount process timed out. Killing."); + mount_enter_signal(m, MOUNT_UNMOUNTING_SIGKILL, MOUNT_FAILURE_TIMEOUT); + } else { + log_unit_warning(UNIT(m), "Mount process timed out. Skipping SIGKILL. Ignoring."); + mount_enter_dead_or_mounted(m, MOUNT_FAILURE_TIMEOUT); + } + break; + + case MOUNT_UNMOUNTING_SIGKILL: + log_unit_warning(UNIT(m), "Mount process still around after SIGKILL. Ignoring."); + mount_enter_dead_or_mounted(m, MOUNT_FAILURE_TIMEOUT); + break; + + default: + assert_not_reached("Timeout at wrong time."); + } + + return 0; +} + +static int mount_setup_new_unit( + Manager *m, + const char *name, + const char *what, + const char *where, + const char *options, + const char *fstype, + MountProcFlags *ret_flags, + Unit **ret) { + + _cleanup_(unit_freep) Unit *u = NULL; + int r; + + assert(m); + assert(name); + assert(ret_flags); + assert(ret); + + r = unit_new_for_name(m, sizeof(Mount), name, &u); + if (r < 0) + return r; + + r = free_and_strdup(&u->source_path, "/proc/self/mountinfo"); + if (r < 0) + return r; + + r = free_and_strdup(&MOUNT(u)->where, where); + if (r < 0) + return r; + + r = update_parameters_proc_self_mount_info(MOUNT(u), what, options, fstype); + if (r < 0) + return r; + + /* This unit was generated because /proc/self/mountinfo reported it. Remember this, so that by the time we load + * the unit file for it (and thus add in extra deps right after) we know what source to attributes the deps + * to.*/ + MOUNT(u)->from_proc_self_mountinfo = true; + + /* We have only allocated the stub now, let's enqueue this unit for loading now, so that everything else is + * loaded in now. */ + unit_add_to_load_queue(u); + + *ret_flags = MOUNT_PROC_IS_MOUNTED | MOUNT_PROC_JUST_MOUNTED | MOUNT_PROC_JUST_CHANGED; + *ret = TAKE_PTR(u); + return 0; +} + +static int mount_setup_existing_unit( + Unit *u, + const char *what, + const char *where, + const char *options, + const char *fstype, + MountProcFlags *ret_flags) { + + MountProcFlags flags = MOUNT_PROC_IS_MOUNTED; + int r; + + assert(u); + assert(flags); + + if (!MOUNT(u)->where) { + MOUNT(u)->where = strdup(where); + if (!MOUNT(u)->where) + return -ENOMEM; + } + + r = update_parameters_proc_self_mount_info(MOUNT(u), what, options, fstype); + if (r < 0) + return r; + if (r > 0) + flags |= MOUNT_PROC_JUST_CHANGED; + + if (!MOUNT(u)->from_proc_self_mountinfo || FLAGS_SET(MOUNT(u)->proc_flags, MOUNT_PROC_JUST_MOUNTED)) + flags |= MOUNT_PROC_JUST_MOUNTED; + + MOUNT(u)->from_proc_self_mountinfo = true; + + if (IN_SET(u->load_state, UNIT_NOT_FOUND, UNIT_BAD_SETTING, UNIT_ERROR)) { + /* The unit was previously not found or otherwise not loaded. Now that the unit shows up in + * /proc/self/mountinfo we should reconsider it this, hence set it to UNIT_LOADED. */ + u->load_state = UNIT_LOADED; + u->load_error = 0; + + flags |= MOUNT_PROC_JUST_CHANGED; + } + + if (FLAGS_SET(flags, MOUNT_PROC_JUST_CHANGED)) { + /* If things changed, then make sure that all deps are regenerated. Let's + * first remove all automatic deps, and then add in the new ones. */ + + unit_remove_dependencies(u, UNIT_DEPENDENCY_MOUNTINFO_IMPLICIT); + + r = mount_add_extras(MOUNT(u)); + if (r < 0) + return r; + } + + *ret_flags = flags; + return 0; +} + +static int mount_setup_unit( + Manager *m, + const char *what, + const char *where, + const char *options, + const char *fstype, + bool set_flags) { + + _cleanup_free_ char *e = NULL; + MountProcFlags flags; + Unit *u; + int r; + + assert(m); + assert(what); + assert(where); + assert(options); + assert(fstype); + + /* Ignore API mount points. They should never be referenced in + * dependencies ever. */ + if (mount_point_is_api(where) || mount_point_ignore(where)) + return 0; + + if (streq(fstype, "autofs")) + return 0; + + /* probably some kind of swap, ignore */ + if (!is_path(where)) + return 0; + + r = unit_name_from_path(where, ".mount", &e); + if (r < 0) + return log_error_errno(r, "Failed to generate unit name from path '%s': %m", where); + + u = manager_get_unit(m, e); + if (u) + r = mount_setup_existing_unit(u, what, where, options, fstype, &flags); + else + /* First time we see this mount point meaning that it's not been initiated by a mount unit but rather + * by the sysadmin having called mount(8) directly. */ + r = mount_setup_new_unit(m, e, what, where, options, fstype, &flags, &u); + if (r < 0) + return log_warning_errno(r, "Failed to set up mount unit: %m"); + + /* If the mount changed properties or state, let's notify our clients */ + if (flags & (MOUNT_PROC_JUST_CHANGED|MOUNT_PROC_JUST_MOUNTED)) + unit_add_to_dbus_queue(u); + + if (set_flags) + MOUNT(u)->proc_flags = flags; + + return 0; +} + +static int mount_load_proc_self_mountinfo(Manager *m, bool set_flags) { + _cleanup_(mnt_free_tablep) struct libmnt_table *t = NULL; + _cleanup_(mnt_free_iterp) struct libmnt_iter *i = NULL; + int r; + + assert(m); + + t = mnt_new_table(); + i = mnt_new_iter(MNT_ITER_FORWARD); + if (!t || !i) + return log_oom(); + + r = mnt_table_parse_mtab(t, NULL); + if (r < 0) + return log_error_errno(r, "Failed to parse /proc/self/mountinfo: %m"); + + for (;;) { + struct libmnt_fs *fs; + const char *device, *path, *options, *fstype; + _cleanup_free_ char *d = NULL, *p = NULL; + int k; + + k = mnt_table_next_fs(t, i, &fs); + if (k == 1) + break; + if (k < 0) + return log_error_errno(k, "Failed to get next entry from /proc/self/mountinfo: %m"); + + device = mnt_fs_get_source(fs); + path = mnt_fs_get_target(fs); + options = mnt_fs_get_options(fs); + fstype = mnt_fs_get_fstype(fs); + + if (!device || !path) + continue; + + if (cunescape(device, UNESCAPE_RELAX, &d) < 0) + return log_oom(); + + if (cunescape(path, UNESCAPE_RELAX, &p) < 0) + return log_oom(); + + device_found_node(m, d, DEVICE_FOUND_MOUNT, DEVICE_FOUND_MOUNT); + + (void) mount_setup_unit(m, d, p, options, fstype, set_flags); + } + + return 0; +} + +static void mount_shutdown(Manager *m) { + assert(m); + + m->mount_event_source = sd_event_source_unref(m->mount_event_source); + + mnt_unref_monitor(m->mount_monitor); + m->mount_monitor = NULL; +} + +static int mount_get_timeout(Unit *u, usec_t *timeout) { + Mount *m = MOUNT(u); + usec_t t; + int r; + + if (!m->timer_event_source) + return 0; + + r = sd_event_source_get_time(m->timer_event_source, &t); + if (r < 0) + return r; + if (t == USEC_INFINITY) + return 0; + + *timeout = t; + return 1; +} + +static void mount_enumerate_perpetual(Manager *m) { + Unit *u; + int r; + + assert(m); + + /* Whatever happens, we know for sure that the root directory is around, and cannot go away. Let's + * unconditionally synthesize it here and mark it as perpetual. */ + + u = manager_get_unit(m, SPECIAL_ROOT_MOUNT); + if (!u) { + r = unit_new_for_name(m, sizeof(Mount), SPECIAL_ROOT_MOUNT, &u); + if (r < 0) { + log_error_errno(r, "Failed to allocate the special " SPECIAL_ROOT_MOUNT " unit: %m"); + return; + } + } + + u->perpetual = true; + MOUNT(u)->deserialized_state = MOUNT_MOUNTED; + + unit_add_to_load_queue(u); + unit_add_to_dbus_queue(u); +} + +static bool mount_is_mounted(Mount *m) { + assert(m); + + return UNIT(m)->perpetual || FLAGS_SET(m->proc_flags, MOUNT_PROC_IS_MOUNTED); +} + +static void mount_enumerate(Manager *m) { + int r; + + assert(m); + + mnt_init_debug(0); + + if (!m->mount_monitor) { + int fd; + + m->mount_monitor = mnt_new_monitor(); + if (!m->mount_monitor) { + log_oom(); + goto fail; + } + + r = mnt_monitor_enable_kernel(m->mount_monitor, 1); + if (r < 0) { + log_error_errno(r, "Failed to enable watching of kernel mount events: %m"); + goto fail; + } + + r = mnt_monitor_enable_userspace(m->mount_monitor, 1, NULL); + if (r < 0) { + log_error_errno(r, "Failed to enable watching of userspace mount events: %m"); + goto fail; + } + + /* mnt_unref_monitor() will close the fd */ + fd = r = mnt_monitor_get_fd(m->mount_monitor); + if (r < 0) { + log_error_errno(r, "Failed to acquire watch file descriptor: %m"); + goto fail; + } + + r = sd_event_add_io(m->event, &m->mount_event_source, fd, EPOLLIN, mount_dispatch_io, m); + if (r < 0) { + log_error_errno(r, "Failed to watch mount file descriptor: %m"); + goto fail; + } + + r = sd_event_source_set_priority(m->mount_event_source, SD_EVENT_PRIORITY_NORMAL-10); + if (r < 0) { + log_error_errno(r, "Failed to adjust mount watch priority: %m"); + goto fail; + } + + (void) sd_event_source_set_description(m->mount_event_source, "mount-monitor-dispatch"); + } + + r = mount_load_proc_self_mountinfo(m, false); + if (r < 0) + goto fail; + + return; + +fail: + mount_shutdown(m); +} + +static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) { + _cleanup_set_free_free_ Set *around = NULL, *gone = NULL; + Manager *m = userdata; + const char *what; + Iterator i; + Unit *u; + int r; + + assert(m); + assert(revents & EPOLLIN); + + if (fd == mnt_monitor_get_fd(m->mount_monitor)) { + bool rescan = false; + + /* Drain all events and verify that the event is valid. + * + * Note that libmount also monitors /run/mount mkdir if the + * directory does not exist yet. The mkdir may generate event + * which is irrelevant for us. + * + * error: r < 0; valid: r == 0, false positive: rc == 1 */ + do { + r = mnt_monitor_next_change(m->mount_monitor, NULL, NULL); + if (r == 0) + rescan = true; + else if (r < 0) + return log_error_errno(r, "Failed to drain libmount events: %m"); + } while (r == 0); + + log_debug("libmount event [rescan: %s]", yes_no(rescan)); + if (!rescan) + return 0; + } + + r = mount_load_proc_self_mountinfo(m, true); + if (r < 0) { + /* Reset flags, just in case, for later calls */ + LIST_FOREACH(units_by_type, u, m->units_by_type[UNIT_MOUNT]) + MOUNT(u)->proc_flags = 0; + + return 0; + } + + manager_dispatch_load_queue(m); + + LIST_FOREACH(units_by_type, u, m->units_by_type[UNIT_MOUNT]) { + Mount *mount = MOUNT(u); + + if (!mount_is_mounted(mount)) { + + /* A mount point is not around right now. It + * might be gone, or might never have + * existed. */ + + if (mount->from_proc_self_mountinfo && + mount->parameters_proc_self_mountinfo.what) { + + /* Remember that this device might just have disappeared */ + if (set_ensure_allocated(&gone, &path_hash_ops) < 0 || + set_put_strdup(gone, mount->parameters_proc_self_mountinfo.what) < 0) + log_oom(); /* we don't care too much about OOM here... */ + } + + mount->from_proc_self_mountinfo = false; + assert_se(update_parameters_proc_self_mount_info(mount, NULL, NULL, NULL) >= 0); + + switch (mount->state) { + + case MOUNT_MOUNTED: + /* This has just been unmounted by somebody else, follow the state change. */ + mount_enter_dead(mount, MOUNT_SUCCESS); + break; + + default: + break; + } + + } else if (mount->proc_flags & (MOUNT_PROC_JUST_MOUNTED|MOUNT_PROC_JUST_CHANGED)) { + + /* A mount point was added or changed */ + + switch (mount->state) { + + case MOUNT_DEAD: + case MOUNT_FAILED: + + /* This has just been mounted by somebody else, follow the state change, but let's + * generate a new invocation ID for this implicitly and automatically. */ + (void) unit_acquire_invocation_id(u); + mount_cycle_clear(mount); + mount_enter_mounted(mount, MOUNT_SUCCESS); + break; + + case MOUNT_MOUNTING: + mount_set_state(mount, MOUNT_MOUNTING_DONE); + break; + + default: + /* Nothing really changed, but let's + * issue an notification call + * nonetheless, in case somebody is + * waiting for this. (e.g. file system + * ro/rw remounts.) */ + mount_set_state(mount, mount->state); + break; + } + } + + if (mount_is_mounted(mount) && + mount->from_proc_self_mountinfo && + mount->parameters_proc_self_mountinfo.what) { + /* Track devices currently used */ + + if (set_ensure_allocated(&around, &path_hash_ops) < 0 || + set_put_strdup(around, mount->parameters_proc_self_mountinfo.what) < 0) + log_oom(); + } + + /* Reset the flags for later calls */ + mount->proc_flags = 0; + } + + SET_FOREACH(what, gone, i) { + if (set_contains(around, what)) + continue; + + /* Let the device units know that the device is no longer mounted */ + device_found_node(m, what, 0, DEVICE_FOUND_MOUNT); + } + + return 0; +} + +static void mount_reset_failed(Unit *u) { + Mount *m = MOUNT(u); + + assert(m); + + if (m->state == MOUNT_FAILED) + mount_set_state(m, MOUNT_DEAD); + + m->result = MOUNT_SUCCESS; + m->reload_result = MOUNT_SUCCESS; +} + +static int mount_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) { + Mount *m = MOUNT(u); + + assert(m); + + return unit_kill_common(u, who, signo, -1, MOUNT(u)->control_pid, error); +} + +static int mount_control_pid(Unit *u) { + Mount *m = MOUNT(u); + + assert(m); + + return m->control_pid; +} + +static const char* const mount_exec_command_table[_MOUNT_EXEC_COMMAND_MAX] = { + [MOUNT_EXEC_MOUNT] = "ExecMount", + [MOUNT_EXEC_UNMOUNT] = "ExecUnmount", + [MOUNT_EXEC_REMOUNT] = "ExecRemount", +}; + +DEFINE_STRING_TABLE_LOOKUP(mount_exec_command, MountExecCommand); + +static const char* const mount_result_table[_MOUNT_RESULT_MAX] = { + [MOUNT_SUCCESS] = "success", + [MOUNT_FAILURE_RESOURCES] = "resources", + [MOUNT_FAILURE_TIMEOUT] = "timeout", + [MOUNT_FAILURE_EXIT_CODE] = "exit-code", + [MOUNT_FAILURE_SIGNAL] = "signal", + [MOUNT_FAILURE_CORE_DUMP] = "core-dump", + [MOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit", + [MOUNT_FAILURE_PROTOCOL] = "protocol", +}; + +DEFINE_STRING_TABLE_LOOKUP(mount_result, MountResult); + +const UnitVTable mount_vtable = { + .object_size = sizeof(Mount), + .exec_context_offset = offsetof(Mount, exec_context), + .cgroup_context_offset = offsetof(Mount, cgroup_context), + .kill_context_offset = offsetof(Mount, kill_context), + .exec_runtime_offset = offsetof(Mount, exec_runtime), + .dynamic_creds_offset = offsetof(Mount, dynamic_creds), + + .sections = + "Unit\0" + "Mount\0" + "Install\0", + .private_section = "Mount", + + .init = mount_init, + .load = mount_load, + .done = mount_done, + + .coldplug = mount_coldplug, + + .dump = mount_dump, + + .start = mount_start, + .stop = mount_stop, + .reload = mount_reload, + + .kill = mount_kill, + + .serialize = mount_serialize, + .deserialize_item = mount_deserialize_item, + + .active_state = mount_active_state, + .sub_state_to_string = mount_sub_state_to_string, + + .may_gc = mount_may_gc, + + .sigchld_event = mount_sigchld_event, + + .reset_failed = mount_reset_failed, + + .control_pid = mount_control_pid, + + .bus_vtable = bus_mount_vtable, + .bus_set_property = bus_mount_set_property, + .bus_commit_properties = bus_mount_commit_properties, + + .get_timeout = mount_get_timeout, + + .can_transient = true, + + .enumerate_perpetual = mount_enumerate_perpetual, + .enumerate = mount_enumerate, + .shutdown = mount_shutdown, + + .status_message_formats = { + .starting_stopping = { + [0] = "Mounting %s...", + [1] = "Unmounting %s...", + }, + .finished_start_job = { + [JOB_DONE] = "Mounted %s.", + [JOB_FAILED] = "Failed to mount %s.", + [JOB_TIMEOUT] = "Timed out mounting %s.", + }, + .finished_stop_job = { + [JOB_DONE] = "Unmounted %s.", + [JOB_FAILED] = "Failed unmounting %s.", + [JOB_TIMEOUT] = "Timed out unmounting %s.", + }, + }, +}; |