/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include #include "sd-device.h" #include "alloc-util.h" #include "dbus-swap.h" #include "dbus-unit.h" #include "device-util.h" #include "device.h" #include "escape.h" #include "exit-status.h" #include "fd-util.h" #include "format-util.h" #include "fstab-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 "swap.h" #include "unit-name.h" #include "unit.h" #include "virt.h" static const UnitActiveState state_translation_table[_SWAP_STATE_MAX] = { [SWAP_DEAD] = UNIT_INACTIVE, [SWAP_ACTIVATING] = UNIT_ACTIVATING, [SWAP_ACTIVATING_DONE] = UNIT_ACTIVE, [SWAP_ACTIVE] = UNIT_ACTIVE, [SWAP_DEACTIVATING] = UNIT_DEACTIVATING, [SWAP_DEACTIVATING_SIGTERM] = UNIT_DEACTIVATING, [SWAP_DEACTIVATING_SIGKILL] = UNIT_DEACTIVATING, [SWAP_FAILED] = UNIT_FAILED, [SWAP_CLEANING] = UNIT_MAINTENANCE, }; static int swap_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata); static int swap_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata); static int swap_process_proc_swaps(Manager *m); static bool SWAP_STATE_WITH_PROCESS(SwapState state) { return IN_SET(state, SWAP_ACTIVATING, SWAP_ACTIVATING_DONE, SWAP_DEACTIVATING, SWAP_DEACTIVATING_SIGTERM, SWAP_DEACTIVATING_SIGKILL, SWAP_CLEANING); } _pure_ static UnitActiveState swap_active_state(Unit *u) { assert(u); return state_translation_table[SWAP(u)->state]; } _pure_ static const char *swap_sub_state_to_string(Unit *u) { assert(u); return swap_state_to_string(SWAP(u)->state); } _pure_ static bool swap_may_gc(Unit *u) { Swap *s = SWAP(u); assert(s); if (s->from_proc_swaps) return false; return true; } _pure_ static bool swap_is_extrinsic(Unit *u) { assert(SWAP(u)); return MANAGER_IS_USER(u->manager); } static void swap_unset_proc_swaps(Swap *s) { assert(s); if (!s->from_proc_swaps) return; s->parameters_proc_swaps.what = mfree(s->parameters_proc_swaps.what); s->from_proc_swaps = false; } static int swap_set_devnode(Swap *s, const char *devnode) { Hashmap *swaps; Swap *first; int r; assert(s); r = hashmap_ensure_allocated(&UNIT(s)->manager->swaps_by_devnode, &path_hash_ops); if (r < 0) return r; swaps = UNIT(s)->manager->swaps_by_devnode; if (s->devnode) { first = hashmap_get(swaps, s->devnode); LIST_REMOVE(same_devnode, first, s); if (first) hashmap_replace(swaps, first->devnode, first); else hashmap_remove(swaps, s->devnode); s->devnode = mfree(s->devnode); } if (devnode) { s->devnode = strdup(devnode); if (!s->devnode) return -ENOMEM; first = hashmap_get(swaps, s->devnode); LIST_PREPEND(same_devnode, first, s); return hashmap_replace(swaps, first->devnode, first); } return 0; } static void swap_init(Unit *u) { Swap *s = SWAP(u); assert(s); assert(UNIT(s)->load_state == UNIT_STUB); s->timeout_usec = u->manager->default_timeout_start_usec; s->exec_context.std_output = u->manager->default_std_output; s->exec_context.std_error = u->manager->default_std_error; s->control_command_id = _SWAP_EXEC_COMMAND_INVALID; u->ignore_on_isolate = true; } static void swap_unwatch_control_pid(Swap *s) { assert(s); if (s->control_pid <= 0) return; unit_unwatch_pid(UNIT(s), s->control_pid); s->control_pid = 0; } static void swap_done(Unit *u) { Swap *s = SWAP(u); assert(s); swap_unset_proc_swaps(s); swap_set_devnode(s, NULL); s->what = mfree(s->what); s->parameters_fragment.what = mfree(s->parameters_fragment.what); s->parameters_fragment.options = mfree(s->parameters_fragment.options); s->exec_runtime = exec_runtime_unref(s->exec_runtime, false); exec_command_done_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX); s->control_command = NULL; dynamic_creds_unref(&s->dynamic_creds); swap_unwatch_control_pid(s); s->timer_event_source = sd_event_source_disable_unref(s->timer_event_source); } static int swap_arm_timer(Swap *s, usec_t usec) { int r; assert(s); if (s->timer_event_source) { r = sd_event_source_set_time(s->timer_event_source, usec); if (r < 0) return r; return sd_event_source_set_enabled(s->timer_event_source, SD_EVENT_ONESHOT); } if (usec == USEC_INFINITY) return 0; r = sd_event_add_time( UNIT(s)->manager->event, &s->timer_event_source, CLOCK_MONOTONIC, usec, 0, swap_dispatch_timer, s); if (r < 0) return r; (void) sd_event_source_set_description(s->timer_event_source, "swap-timer"); return 0; } static SwapParameters* swap_get_parameters(Swap *s) { assert(s); if (s->from_proc_swaps) return &s->parameters_proc_swaps; if (s->from_fragment) return &s->parameters_fragment; return NULL; } static int swap_add_device_dependencies(Swap *s) { UnitDependencyMask mask; SwapParameters *p; int r; assert(s); if (!s->what) return 0; p = swap_get_parameters(s); if (!p || !p->what) return 0; mask = s->from_proc_swaps ? UNIT_DEPENDENCY_PROC_SWAP : UNIT_DEPENDENCY_FILE; if (is_device_path(p->what)) { r = unit_add_node_dependency(UNIT(s), p->what, UNIT_REQUIRES, mask); if (r < 0) return r; return unit_add_blockdev_dependency(UNIT(s), p->what, mask); } /* File based swap devices need to be ordered after systemd-remount-fs.service, since they might need * a writable file system. */ return unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, SPECIAL_REMOUNT_FS_SERVICE, true, mask); } static int swap_add_default_dependencies(Swap *s) { int r; assert(s); if (!UNIT(s)->default_dependencies) return 0; if (!MANAGER_IS_SYSTEM(UNIT(s)->manager)) return 0; if (detect_container() > 0) return 0; /* swap units generated for the swap dev links are missing the * ordering dep against the swap target. */ r = unit_add_dependency_by_name(UNIT(s), UNIT_BEFORE, SPECIAL_SWAP_TARGET, true, UNIT_DEPENDENCY_DEFAULT); if (r < 0) return r; return unit_add_two_dependencies_by_name(UNIT(s), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, true, UNIT_DEPENDENCY_DEFAULT); } static int swap_verify(Swap *s) { _cleanup_free_ char *e = NULL; int r; assert(UNIT(s)->load_state == UNIT_LOADED); r = unit_name_from_path(s->what, ".swap", &e); if (r < 0) return log_unit_error_errno(UNIT(s), r, "Failed to generate unit name from path: %m"); if (!unit_has_name(UNIT(s), e)) return log_unit_error_errno(UNIT(s), SYNTHETIC_ERRNO(ENOEXEC), "Value of What= and unit name do not match, not loading."); if (s->exec_context.pam_name && s->kill_context.kill_mode != KILL_CONTROL_GROUP) return log_unit_error_errno(UNIT(s), SYNTHETIC_ERRNO(ENOEXEC), "Unit has PAM enabled. Kill mode must be set to 'control-group'. Refusing to load."); return 0; } static int swap_load_devnode(Swap *s) { _cleanup_(sd_device_unrefp) sd_device *d = NULL; struct stat st; const char *p; int r; assert(s); if (stat(s->what, &st) < 0 || !S_ISBLK(st.st_mode)) return 0; r = sd_device_new_from_stat_rdev(&d, &st); if (r < 0) { log_unit_full_errno(UNIT(s), r == -ENOENT ? LOG_DEBUG : LOG_WARNING, r, "Failed to allocate device for swap %s: %m", s->what); return 0; } if (sd_device_get_devname(d, &p) < 0) return 0; return swap_set_devnode(s, p); } static int swap_add_extras(Swap *s) { int r; assert(s); if (UNIT(s)->fragment_path) s->from_fragment = true; if (!s->what) { if (s->parameters_fragment.what) s->what = strdup(s->parameters_fragment.what); else if (s->parameters_proc_swaps.what) s->what = strdup(s->parameters_proc_swaps.what); else { r = unit_name_to_path(UNIT(s)->id, &s->what); if (r < 0) return r; } if (!s->what) return -ENOMEM; } path_simplify(s->what); if (!UNIT(s)->description) { r = unit_set_description(UNIT(s), s->what); if (r < 0) return r; } r = unit_require_mounts_for(UNIT(s), s->what, UNIT_DEPENDENCY_IMPLICIT); if (r < 0) return r; r = swap_add_device_dependencies(s); if (r < 0) return r; r = swap_load_devnode(s); if (r < 0) return r; r = unit_patch_contexts(UNIT(s)); if (r < 0) return r; r = unit_add_exec_dependencies(UNIT(s), &s->exec_context); if (r < 0) return r; r = unit_set_default_slice(UNIT(s)); if (r < 0) return r; r = swap_add_default_dependencies(s); if (r < 0) return r; return 0; } static int swap_load(Unit *u) { Swap *s = SWAP(u); int r, q = 0; assert(s); assert(u->load_state == UNIT_STUB); /* Load a .swap file */ bool fragment_optional = s->from_proc_swaps; r = unit_load_fragment_and_dropin(u, !fragment_optional); /* Add in some extras, and do so either when we successfully loaded something or when /proc/swaps is * already active. */ if (u->load_state == UNIT_LOADED || s->from_proc_swaps) q = swap_add_extras(s); if (r < 0) return r; if (q < 0) return q; if (u->load_state != UNIT_LOADED) return 0; return swap_verify(s); } static int swap_setup_unit( Manager *m, const char *what, const char *what_proc_swaps, int priority, bool set_flags) { _cleanup_free_ char *e = NULL; bool delete = false; Unit *u = NULL; int r; SwapParameters *p; assert(m); assert(what); assert(what_proc_swaps); r = unit_name_from_path(what, ".swap", &e); if (r < 0) return log_unit_error_errno(u, r, "Failed to generate unit name from path: %m"); u = manager_get_unit(m, e); if (u && SWAP(u)->from_proc_swaps && !path_equal(SWAP(u)->parameters_proc_swaps.what, what_proc_swaps)) return log_error_errno(SYNTHETIC_ERRNO(EEXIST), "Swap %s appeared twice with different device paths %s and %s", e, SWAP(u)->parameters_proc_swaps.what, what_proc_swaps); if (!u) { delete = true; r = unit_new_for_name(m, sizeof(Swap), e, &u); if (r < 0) goto fail; SWAP(u)->what = strdup(what); if (!SWAP(u)->what) { r = -ENOMEM; goto fail; } unit_add_to_load_queue(u); } else delete = false; p = &SWAP(u)->parameters_proc_swaps; if (!p->what) { p->what = strdup(what_proc_swaps); if (!p->what) { r = -ENOMEM; goto fail; } } /* The unit is definitely around now, mark it as loaded if it was previously referenced but could not be * loaded. After all we can load it now, from the data in /proc/swaps. */ if (IN_SET(u->load_state, UNIT_NOT_FOUND, UNIT_BAD_SETTING, UNIT_ERROR)) { u->load_state = UNIT_LOADED; u->load_error = 0; } if (set_flags) { SWAP(u)->is_active = true; SWAP(u)->just_activated = !SWAP(u)->from_proc_swaps; } SWAP(u)->from_proc_swaps = true; p->priority = priority; p->priority_set = true; unit_add_to_dbus_queue(u); return 0; fail: log_unit_warning_errno(u, r, "Failed to load swap unit: %m"); if (delete) unit_free(u); return r; } static void swap_process_new(Manager *m, const char *device, int prio, bool set_flags) { _cleanup_(sd_device_unrefp) sd_device *d = NULL; const char *dn, *devlink; struct stat st, st_link; int r; assert(m); if (swap_setup_unit(m, device, device, prio, set_flags) < 0) return; /* If this is a block device, then let's add duplicates for * all other names of this block device */ if (stat(device, &st) < 0 || !S_ISBLK(st.st_mode)) return; r = sd_device_new_from_stat_rdev(&d, &st); if (r < 0) return (void) log_full_errno(r == -ENOENT ? LOG_DEBUG : LOG_WARNING, r, "Failed to allocate device for swap %s: %m", device); /* Add the main device node */ if (sd_device_get_devname(d, &dn) >= 0 && !streq(dn, device)) (void) swap_setup_unit(m, dn, device, prio, set_flags); /* Add additional units for all symlinks */ FOREACH_DEVICE_DEVLINK(d, devlink) { /* Don't bother with the /dev/block links */ if (streq(devlink, device)) continue; if (path_startswith(devlink, "/dev/block/")) continue; if (stat(devlink, &st_link) >= 0 && (!S_ISBLK(st_link.st_mode) || st_link.st_rdev != st.st_rdev)) continue; (void) swap_setup_unit(m, devlink, device, prio, set_flags); } } static void swap_set_state(Swap *s, SwapState state) { SwapState old_state; Swap *other; assert(s); if (s->state != state) bus_unit_send_pending_change_signal(UNIT(s), false); old_state = s->state; s->state = state; if (!SWAP_STATE_WITH_PROCESS(state)) { s->timer_event_source = sd_event_source_disable_unref(s->timer_event_source); swap_unwatch_control_pid(s); s->control_command = NULL; s->control_command_id = _SWAP_EXEC_COMMAND_INVALID; } if (state != old_state) log_unit_debug(UNIT(s), "Changed %s -> %s", swap_state_to_string(old_state), swap_state_to_string(state)); unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], 0); /* If there other units for the same device node have a job queued it might be worth checking again if it is runnable now. This is necessary, since swap_start() refuses operation with EAGAIN if there's already another job for the same device node queued. */ LIST_FOREACH_OTHERS(same_devnode, other, s) if (UNIT(other)->job) job_add_to_run_queue(UNIT(other)->job); } static int swap_coldplug(Unit *u) { Swap *s = SWAP(u); SwapState new_state = SWAP_DEAD; int r; assert(s); assert(s->state == SWAP_DEAD); if (s->deserialized_state != s->state) new_state = s->deserialized_state; else if (s->from_proc_swaps) new_state = SWAP_ACTIVE; if (new_state == s->state) return 0; if (s->control_pid > 0 && pid_is_unwaited(s->control_pid) && SWAP_STATE_WITH_PROCESS(new_state)) { r = unit_watch_pid(UNIT(s), s->control_pid, false); if (r < 0) return r; r = swap_arm_timer(s, usec_add(u->state_change_timestamp.monotonic, s->timeout_usec)); if (r < 0) return r; } if (!IN_SET(new_state, SWAP_DEAD, SWAP_FAILED)) { (void) unit_setup_dynamic_creds(u); (void) unit_setup_exec_runtime(u); } swap_set_state(s, new_state); return 0; } static void swap_dump(Unit *u, FILE *f, const char *prefix) { Swap *s = SWAP(u); SwapParameters *p; assert(s); assert(f); if (s->from_proc_swaps) p = &s->parameters_proc_swaps; else if (s->from_fragment) p = &s->parameters_fragment; else p = NULL; fprintf(f, "%sSwap State: %s\n" "%sResult: %s\n" "%sClean Result: %s\n" "%sWhat: %s\n" "%sFrom /proc/swaps: %s\n" "%sFrom fragment: %s\n" "%sExtrinsic: %s\n", prefix, swap_state_to_string(s->state), prefix, swap_result_to_string(s->result), prefix, swap_result_to_string(s->clean_result), prefix, s->what, prefix, yes_no(s->from_proc_swaps), prefix, yes_no(s->from_fragment), prefix, yes_no(swap_is_extrinsic(u))); if (s->devnode) fprintf(f, "%sDevice Node: %s\n", prefix, s->devnode); if (p) fprintf(f, "%sPriority: %i\n" "%sOptions: %s\n", prefix, p->priority, prefix, strempty(p->options)); fprintf(f, "%sTimeoutSec: %s\n", prefix, FORMAT_TIMESPAN(s->timeout_usec, USEC_PER_SEC)); if (s->control_pid > 0) fprintf(f, "%sControl PID: "PID_FMT"\n", prefix, s->control_pid); exec_context_dump(&s->exec_context, f, prefix); kill_context_dump(&s->kill_context, f, prefix); cgroup_context_dump(UNIT(s), f, prefix); } static int swap_spawn(Swap *s, 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(s); assert(c); assert(_pid); r = unit_prepare_exec(UNIT(s)); if (r < 0) return r; r = swap_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_usec)); if (r < 0) goto fail; r = unit_set_exec_params(UNIT(s), &exec_params); if (r < 0) goto fail; r = exec_spawn(UNIT(s), c, &s->exec_context, &exec_params, s->exec_runtime, &s->dynamic_creds, &pid); if (r < 0) goto fail; r = unit_watch_pid(UNIT(s), pid, true); if (r < 0) goto fail; *_pid = pid; return 0; fail: s->timer_event_source = sd_event_source_disable_unref(s->timer_event_source); return r; } static void swap_enter_dead(Swap *s, SwapResult f) { assert(s); if (s->result == SWAP_SUCCESS) s->result = f; unit_log_result(UNIT(s), s->result == SWAP_SUCCESS, swap_result_to_string(s->result)); unit_warn_leftover_processes(UNIT(s), unit_log_leftover_process_stop); swap_set_state(s, s->result != SWAP_SUCCESS ? SWAP_FAILED : SWAP_DEAD); s->exec_runtime = exec_runtime_unref(s->exec_runtime, true); unit_destroy_runtime_data(UNIT(s), &s->exec_context); unit_unref_uid_gid(UNIT(s), true); dynamic_creds_destroy(&s->dynamic_creds); } static void swap_enter_active(Swap *s, SwapResult f) { assert(s); if (s->result == SWAP_SUCCESS) s->result = f; swap_set_state(s, SWAP_ACTIVE); } static void swap_enter_dead_or_active(Swap *s, SwapResult f) { assert(s); if (s->from_proc_swaps) { Swap *other; swap_enter_active(s, f); LIST_FOREACH_OTHERS(same_devnode, other, s) if (UNIT(other)->job) swap_enter_dead_or_active(other, f); } else swap_enter_dead(s, f); } static int state_to_kill_operation(Swap *s, SwapState state) { if (state == SWAP_DEACTIVATING_SIGTERM) { if (unit_has_job_type(UNIT(s), JOB_RESTART)) return KILL_RESTART; else return KILL_TERMINATE; } return KILL_KILL; } static void swap_enter_signal(Swap *s, SwapState state, SwapResult f) { int r; assert(s); if (s->result == SWAP_SUCCESS) s->result = f; r = unit_kill_context(UNIT(s), &s->kill_context, state_to_kill_operation(s, state), -1, s->control_pid, false); if (r < 0) goto fail; if (r > 0) { r = swap_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_usec)); if (r < 0) goto fail; swap_set_state(s, state); } else if (state == SWAP_DEACTIVATING_SIGTERM && s->kill_context.send_sigkill) swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, SWAP_SUCCESS); else swap_enter_dead_or_active(s, SWAP_SUCCESS); return; fail: log_unit_warning_errno(UNIT(s), r, "Failed to kill processes: %m"); swap_enter_dead_or_active(s, SWAP_FAILURE_RESOURCES); } static void swap_enter_activating(Swap *s) { _cleanup_free_ char *opts = NULL; int r; assert(s); unit_warn_leftover_processes(UNIT(s), unit_log_leftover_process_start); s->control_command_id = SWAP_EXEC_ACTIVATE; s->control_command = s->exec_command + SWAP_EXEC_ACTIVATE; if (s->from_fragment) { int priority = 0; r = fstab_find_pri(s->parameters_fragment.options, &priority); if (r < 0) log_unit_warning_errno(UNIT(s), r, "Failed to parse swap priority \"%s\", ignoring: %m", s->parameters_fragment.options); else if (r > 0 && s->parameters_fragment.priority_set) log_unit_warning(UNIT(s), "Duplicate swap priority configuration by Priority= and Options= fields."); if (r <= 0 && s->parameters_fragment.priority_set) { if (s->parameters_fragment.options) r = asprintf(&opts, "%s,pri=%i", s->parameters_fragment.options, s->parameters_fragment.priority); else r = asprintf(&opts, "pri=%i", s->parameters_fragment.priority); if (r < 0) { r = -ENOMEM; goto fail; } } } r = exec_command_set(s->control_command, "/sbin/swapon", NULL); if (r < 0) goto fail; if (s->parameters_fragment.options || opts) { r = exec_command_append(s->control_command, "-o", opts ?: s->parameters_fragment.options, NULL); if (r < 0) goto fail; } r = exec_command_append(s->control_command, s->what, NULL); if (r < 0) goto fail; swap_unwatch_control_pid(s); r = swap_spawn(s, s->control_command, &s->control_pid); if (r < 0) goto fail; swap_set_state(s, SWAP_ACTIVATING); return; fail: log_unit_warning_errno(UNIT(s), r, "Failed to run 'swapon' task: %m"); swap_enter_dead_or_active(s, SWAP_FAILURE_RESOURCES); } static void swap_enter_deactivating(Swap *s) { int r; assert(s); s->control_command_id = SWAP_EXEC_DEACTIVATE; s->control_command = s->exec_command + SWAP_EXEC_DEACTIVATE; r = exec_command_set(s->control_command, "/sbin/swapoff", s->what, NULL); if (r < 0) goto fail; swap_unwatch_control_pid(s); r = swap_spawn(s, s->control_command, &s->control_pid); if (r < 0) goto fail; swap_set_state(s, SWAP_DEACTIVATING); return; fail: log_unit_warning_errno(UNIT(s), r, "Failed to run 'swapoff' task: %m"); swap_enter_dead_or_active(s, SWAP_FAILURE_RESOURCES); } static void swap_cycle_clear(Swap *s) { assert(s); s->result = SWAP_SUCCESS; exec_command_reset_status_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX); UNIT(s)->reset_accounting = true; } static int swap_start(Unit *u) { Swap *s = SWAP(u), *other; int r; assert(s); /* We cannot fulfill this request right now, try again later please! */ if (IN_SET(s->state, SWAP_DEACTIVATING, SWAP_DEACTIVATING_SIGTERM, SWAP_DEACTIVATING_SIGKILL, SWAP_CLEANING)) return -EAGAIN; /* Already on it! */ if (s->state == SWAP_ACTIVATING) return 0; assert(IN_SET(s->state, SWAP_DEAD, SWAP_FAILED)); if (detect_container() > 0) return -EPERM; /* If there's a job for another swap unit for the same node * running, then let's not dispatch this one for now, and wait * until that other job has finished. */ LIST_FOREACH_OTHERS(same_devnode, other, s) if (UNIT(other)->job && UNIT(other)->job->state == JOB_RUNNING) return -EAGAIN; r = unit_test_start_limit(u); if (r < 0) { swap_enter_dead(s, SWAP_FAILURE_START_LIMIT_HIT); return r; } r = unit_acquire_invocation_id(u); if (r < 0) return r; swap_cycle_clear(s); swap_enter_activating(s); return 1; } static int swap_stop(Unit *u) { Swap *s = SWAP(u); assert(s); switch (s->state) { case SWAP_DEACTIVATING: case SWAP_DEACTIVATING_SIGTERM: case SWAP_DEACTIVATING_SIGKILL: /* Already on it */ return 0; case SWAP_ACTIVATING: case SWAP_ACTIVATING_DONE: /* There's a control process pending, directly enter kill mode */ swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, SWAP_SUCCESS); return 0; case SWAP_ACTIVE: if (detect_container() > 0) return -EPERM; swap_enter_deactivating(s); return 1; case SWAP_CLEANING: /* If we are currently cleaning, then abort it, brutally. */ swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, SWAP_SUCCESS); return 0; default: assert_not_reached("Unexpected state."); } } static int swap_serialize(Unit *u, FILE *f, FDSet *fds) { Swap *s = SWAP(u); assert(s); assert(f); assert(fds); (void) serialize_item(f, "state", swap_state_to_string(s->state)); (void) serialize_item(f, "result", swap_result_to_string(s->result)); if (s->control_pid > 0) (void) serialize_item_format(f, "control-pid", PID_FMT, s->control_pid); if (s->control_command_id >= 0) (void) serialize_item(f, "control-command", swap_exec_command_to_string(s->control_command_id)); return 0; } static int swap_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) { Swap *s = SWAP(u); assert(s); assert(fds); if (streq(key, "state")) { SwapState state; state = swap_state_from_string(value); if (state < 0) log_unit_debug(u, "Failed to parse state value: %s", value); else s->deserialized_state = state; } else if (streq(key, "result")) { SwapResult f; f = swap_result_from_string(value); if (f < 0) log_unit_debug(u, "Failed to parse result value: %s", value); else if (f != SWAP_SUCCESS) s->result = f; } else if (streq(key, "control-pid")) { pid_t pid; if (parse_pid(value, &pid) < 0) log_unit_debug(u, "Failed to parse control-pid value: %s", value); else s->control_pid = pid; } else if (streq(key, "control-command")) { SwapExecCommand id; id = swap_exec_command_from_string(value); if (id < 0) log_unit_debug(u, "Failed to parse exec-command value: %s", value); else { s->control_command_id = id; s->control_command = s->exec_command + id; } } else log_unit_debug(u, "Unknown serialization key: %s", key); return 0; } static void swap_sigchld_event(Unit *u, pid_t pid, int code, int status) { Swap *s = SWAP(u); SwapResult f; assert(s); assert(pid >= 0); if (pid != s->control_pid) return; /* Let's scan /proc/swaps before we process SIGCHLD. For the reasoning see the similar code in * mount.c */ (void) swap_process_proc_swaps(u->manager); s->control_pid = 0; if (is_clean_exit(code, status, EXIT_CLEAN_COMMAND, NULL)) f = SWAP_SUCCESS; else if (code == CLD_EXITED) f = SWAP_FAILURE_EXIT_CODE; else if (code == CLD_KILLED) f = SWAP_FAILURE_SIGNAL; else if (code == CLD_DUMPED) f = SWAP_FAILURE_CORE_DUMP; else assert_not_reached("Unknown code"); if (s->result == SWAP_SUCCESS) s->result = f; if (s->control_command) { exec_status_exit(&s->control_command->exec_status, &s->exec_context, pid, code, status); s->control_command = NULL; s->control_command_id = _SWAP_EXEC_COMMAND_INVALID; } unit_log_process_exit( u, "Swap process", swap_exec_command_to_string(s->control_command_id), f == SWAP_SUCCESS, code, status); switch (s->state) { case SWAP_ACTIVATING: case SWAP_ACTIVATING_DONE: if (f == SWAP_SUCCESS || s->from_proc_swaps) swap_enter_active(s, f); else swap_enter_dead(s, f); break; case SWAP_DEACTIVATING: case SWAP_DEACTIVATING_SIGKILL: case SWAP_DEACTIVATING_SIGTERM: swap_enter_dead_or_active(s, f); break; case SWAP_CLEANING: if (s->clean_result == SWAP_SUCCESS) s->clean_result = f; swap_enter_dead(s, SWAP_SUCCESS); 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 swap_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata) { Swap *s = SWAP(userdata); assert(s); assert(s->timer_event_source == source); switch (s->state) { case SWAP_ACTIVATING: case SWAP_ACTIVATING_DONE: log_unit_warning(UNIT(s), "Activation timed out. Stopping."); swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, SWAP_FAILURE_TIMEOUT); break; case SWAP_DEACTIVATING: log_unit_warning(UNIT(s), "Deactivation timed out. Stopping."); swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, SWAP_FAILURE_TIMEOUT); break; case SWAP_DEACTIVATING_SIGTERM: if (s->kill_context.send_sigkill) { log_unit_warning(UNIT(s), "Swap process timed out. Killing."); swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, SWAP_FAILURE_TIMEOUT); } else { log_unit_warning(UNIT(s), "Swap process timed out. Skipping SIGKILL. Ignoring."); swap_enter_dead_or_active(s, SWAP_FAILURE_TIMEOUT); } break; case SWAP_DEACTIVATING_SIGKILL: log_unit_warning(UNIT(s), "Swap process still around after SIGKILL. Ignoring."); swap_enter_dead_or_active(s, SWAP_FAILURE_TIMEOUT); break; case SWAP_CLEANING: log_unit_warning(UNIT(s), "Cleaning timed out. killing."); if (s->clean_result == SWAP_SUCCESS) s->clean_result = SWAP_FAILURE_TIMEOUT; swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, 0); break; default: assert_not_reached("Timeout at wrong time."); } return 0; } static int swap_load_proc_swaps(Manager *m, bool set_flags) { assert(m); rewind(m->proc_swaps); (void) fscanf(m->proc_swaps, "%*s %*s %*s %*s %*s\n"); for (unsigned i = 1;; i++) { _cleanup_free_ char *dev = NULL, *d = NULL; int prio = 0, k; k = fscanf(m->proc_swaps, "%ms " /* device/file */ "%*s " /* type of swap */ "%*s " /* swap size */ "%*s " /* used */ "%i\n", /* priority */ &dev, &prio); if (k != 2) { if (k == EOF) break; log_warning("Failed to parse /proc/swaps:%u.", i); continue; } ssize_t l = cunescape(dev, UNESCAPE_RELAX, &d); if (l < 0) return log_error_errno(l, "Failed to unescape device path: %m"); device_found_node(m, d, DEVICE_FOUND_SWAP, DEVICE_FOUND_SWAP); (void) swap_process_new(m, d, prio, set_flags); } return 0; } static int swap_process_proc_swaps(Manager *m) { Unit *u; int r; assert(m); r = swap_load_proc_swaps(m, true); if (r < 0) { log_error_errno(r, "Failed to reread /proc/swaps: %m"); /* Reset flags, just in case, for late calls */ LIST_FOREACH(units_by_type, u, m->units_by_type[UNIT_SWAP]) { Swap *swap = SWAP(u); swap->is_active = swap->just_activated = false; } return 0; } manager_dispatch_load_queue(m); LIST_FOREACH(units_by_type, u, m->units_by_type[UNIT_SWAP]) { Swap *swap = SWAP(u); if (!swap->is_active) { swap_unset_proc_swaps(swap); switch (swap->state) { case SWAP_ACTIVE: /* This has just been deactivated */ swap_enter_dead(swap, SWAP_SUCCESS); break; default: /* Fire again */ swap_set_state(swap, swap->state); break; } if (swap->what) device_found_node(m, swap->what, 0, DEVICE_FOUND_SWAP); } else if (swap->just_activated) { /* New swap entry */ switch (swap->state) { case SWAP_DEAD: case SWAP_FAILED: (void) unit_acquire_invocation_id(u); swap_cycle_clear(swap); swap_enter_active(swap, SWAP_SUCCESS); break; case SWAP_ACTIVATING: swap_set_state(swap, SWAP_ACTIVATING_DONE); break; default: /* Nothing really changed, but let's * issue an notification call * nonetheless, in case somebody is * waiting for this. */ swap_set_state(swap, swap->state); break; } } /* Reset the flags for later calls */ swap->is_active = swap->just_activated = false; } return 1; } static int swap_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) { Manager *m = userdata; assert(m); assert(revents & EPOLLPRI); return swap_process_proc_swaps(m); } static Unit *swap_following(Unit *u) { Swap *s = SWAP(u); Swap *other, *first = NULL; assert(s); /* If the user configured the swap through /etc/fstab or * a device unit, follow that. */ if (s->from_fragment) return NULL; LIST_FOREACH_OTHERS(same_devnode, other, s) if (other->from_fragment) return UNIT(other); /* Otherwise, make everybody follow the unit that's named after * the swap device in the kernel */ if (streq_ptr(s->what, s->devnode)) return NULL; LIST_FOREACH_AFTER(same_devnode, other, s) if (streq_ptr(other->what, other->devnode)) return UNIT(other); LIST_FOREACH_BEFORE(same_devnode, other, s) { if (streq_ptr(other->what, other->devnode)) return UNIT(other); first = other; } /* Fall back to the first on the list */ return UNIT(first); } static int swap_following_set(Unit *u, Set **_set) { Swap *s = SWAP(u), *other; _cleanup_set_free_ Set *set = NULL; int r; assert(s); assert(_set); if (LIST_JUST_US(same_devnode, s)) { *_set = NULL; return 0; } set = set_new(NULL); if (!set) return -ENOMEM; LIST_FOREACH_OTHERS(same_devnode, other, s) { r = set_put(set, other); if (r < 0) return r; } *_set = TAKE_PTR(set); return 1; } static void swap_shutdown(Manager *m) { assert(m); m->swap_event_source = sd_event_source_disable_unref(m->swap_event_source); m->proc_swaps = safe_fclose(m->proc_swaps); m->swaps_by_devnode = hashmap_free(m->swaps_by_devnode); } static void swap_enumerate(Manager *m) { int r; assert(m); if (!m->proc_swaps) { m->proc_swaps = fopen("/proc/swaps", "re"); if (!m->proc_swaps) { if (errno == ENOENT) log_debug_errno(errno, "Not swap enabled, skipping enumeration."); else log_warning_errno(errno, "Failed to open /proc/swaps, ignoring: %m"); return; } r = sd_event_add_io(m->event, &m->swap_event_source, fileno(m->proc_swaps), EPOLLPRI, swap_dispatch_io, m); if (r < 0) { log_error_errno(r, "Failed to watch /proc/swaps: %m"); goto fail; } /* Dispatch this before we dispatch SIGCHLD, so that * we always get the events from /proc/swaps before * the SIGCHLD of /sbin/swapon. */ r = sd_event_source_set_priority(m->swap_event_source, SD_EVENT_PRIORITY_NORMAL-10); if (r < 0) { log_error_errno(r, "Failed to change /proc/swaps priority: %m"); goto fail; } (void) sd_event_source_set_description(m->swap_event_source, "swap-proc"); } r = swap_load_proc_swaps(m, false); if (r < 0) goto fail; return; fail: swap_shutdown(m); } int swap_process_device_new(Manager *m, sd_device *dev) { _cleanup_free_ char *e = NULL; const char *dn, *devlink; Unit *u; int r; assert(m); assert(dev); if (sd_device_get_devname(dev, &dn) < 0) return 0; r = unit_name_from_path(dn, ".swap", &e); if (r < 0) { log_debug_errno(r, "Cannot convert device name '%s' to unit name, ignoring: %m", dn); return 0; } u = manager_get_unit(m, e); if (u) r = swap_set_devnode(SWAP(u), dn); FOREACH_DEVICE_DEVLINK(dev, devlink) { _cleanup_free_ char *n = NULL; int q; q = unit_name_from_path(devlink, ".swap", &n); if (IN_SET(q, -EINVAL, -ENAMETOOLONG)) /* If name too long or otherwise not convertible to * unit name, we can't manage it */ continue; if (q < 0) return q; u = manager_get_unit(m, n); if (u) { q = swap_set_devnode(SWAP(u), dn); if (q < 0) r = q; } } return r; } int swap_process_device_remove(Manager *m, sd_device *dev) { const char *dn; int r; Swap *s; r = sd_device_get_devname(dev, &dn); if (r < 0) return 0; while ((s = hashmap_get(m->swaps_by_devnode, dn))) { int q; q = swap_set_devnode(s, NULL); if (q < 0) r = q; } return r; } static void swap_reset_failed(Unit *u) { Swap *s = SWAP(u); assert(s); if (s->state == SWAP_FAILED) swap_set_state(s, SWAP_DEAD); s->result = SWAP_SUCCESS; s->clean_result = SWAP_SUCCESS; } static int swap_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) { return unit_kill_common(u, who, signo, -1, SWAP(u)->control_pid, error); } static int swap_get_timeout(Unit *u, usec_t *timeout) { Swap *s = SWAP(u); usec_t t; int r; if (!s->timer_event_source) return 0; r = sd_event_source_get_time(s->timer_event_source, &t); if (r < 0) return r; if (t == USEC_INFINITY) return 0; *timeout = t; return 1; } static bool swap_supported(void) { static int supported = -1; /* If swap support is not available in the kernel, or we are * running in a container we don't support swap units, and any * attempts to starting one should fail immediately. */ if (supported < 0) supported = access("/proc/swaps", F_OK) >= 0 && detect_container() <= 0; return supported; } static int swap_control_pid(Unit *u) { Swap *s = SWAP(u); assert(s); return s->control_pid; } static int swap_clean(Unit *u, ExecCleanMask mask) { _cleanup_strv_free_ char **l = NULL; Swap *s = SWAP(u); int r; assert(s); assert(mask != 0); if (s->state != SWAP_DEAD) return -EBUSY; r = exec_context_get_clean_directories(&s->exec_context, u->manager->prefix, mask, &l); if (r < 0) return r; if (strv_isempty(l)) return -EUNATCH; swap_unwatch_control_pid(s); s->clean_result = SWAP_SUCCESS; s->control_command = NULL; s->control_command_id = _SWAP_EXEC_COMMAND_INVALID; r = swap_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->exec_context.timeout_clean_usec)); if (r < 0) goto fail; r = unit_fork_and_watch_rm_rf(u, l, &s->control_pid); if (r < 0) goto fail; swap_set_state(s, SWAP_CLEANING); return 0; fail: log_unit_warning_errno(u, r, "Failed to initiate cleaning: %m"); s->clean_result = SWAP_FAILURE_RESOURCES; s->timer_event_source = sd_event_source_disable_unref(s->timer_event_source); return r; } static int swap_can_clean(Unit *u, ExecCleanMask *ret) { Swap *s = SWAP(u); assert(s); return exec_context_get_clean_mask(&s->exec_context, ret); } static const char* const swap_exec_command_table[_SWAP_EXEC_COMMAND_MAX] = { [SWAP_EXEC_ACTIVATE] = "ExecActivate", [SWAP_EXEC_DEACTIVATE] = "ExecDeactivate", }; DEFINE_STRING_TABLE_LOOKUP(swap_exec_command, SwapExecCommand); static const char* const swap_result_table[_SWAP_RESULT_MAX] = { [SWAP_SUCCESS] = "success", [SWAP_FAILURE_RESOURCES] = "resources", [SWAP_FAILURE_TIMEOUT] = "timeout", [SWAP_FAILURE_EXIT_CODE] = "exit-code", [SWAP_FAILURE_SIGNAL] = "signal", [SWAP_FAILURE_CORE_DUMP] = "core-dump", [SWAP_FAILURE_START_LIMIT_HIT] = "start-limit-hit", }; DEFINE_STRING_TABLE_LOOKUP(swap_result, SwapResult); const UnitVTable swap_vtable = { .object_size = sizeof(Swap), .exec_context_offset = offsetof(Swap, exec_context), .cgroup_context_offset = offsetof(Swap, cgroup_context), .kill_context_offset = offsetof(Swap, kill_context), .exec_runtime_offset = offsetof(Swap, exec_runtime), .dynamic_creds_offset = offsetof(Swap, dynamic_creds), .sections = "Unit\0" "Swap\0" "Install\0", .private_section = "Swap", .can_fail = true, .init = swap_init, .load = swap_load, .done = swap_done, .coldplug = swap_coldplug, .dump = swap_dump, .start = swap_start, .stop = swap_stop, .kill = swap_kill, .clean = swap_clean, .can_clean = swap_can_clean, .get_timeout = swap_get_timeout, .serialize = swap_serialize, .deserialize_item = swap_deserialize_item, .active_state = swap_active_state, .sub_state_to_string = swap_sub_state_to_string, .will_restart = unit_will_restart_default, .may_gc = swap_may_gc, .is_extrinsic = swap_is_extrinsic, .sigchld_event = swap_sigchld_event, .reset_failed = swap_reset_failed, .control_pid = swap_control_pid, .bus_set_property = bus_swap_set_property, .bus_commit_properties = bus_swap_commit_properties, .following = swap_following, .following_set = swap_following_set, .enumerate = swap_enumerate, .shutdown = swap_shutdown, .supported = swap_supported, .status_message_formats = { .starting_stopping = { [0] = "Activating swap %s...", [1] = "Deactivating swap %s...", }, .finished_start_job = { [JOB_DONE] = "Activated swap %s.", [JOB_FAILED] = "Failed to activate swap %s.", [JOB_TIMEOUT] = "Timed out activating swap %s.", }, .finished_stop_job = { [JOB_DONE] = "Deactivated swap %s.", [JOB_FAILED] = "Failed deactivating swap %s.", [JOB_TIMEOUT] = "Timed out deactivating swap %s.", }, }, };