diff options
Diffstat (limited to 'src/core/swap.c')
| -rw-r--r-- | src/core/swap.c | 1415 |
1 files changed, 1415 insertions, 0 deletions
diff --git a/src/core/swap.c b/src/core/swap.c new file mode 100644 index 0000000000..9c72732b94 --- /dev/null +++ b/src/core/swap.c @@ -0,0 +1,1415 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2010 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <errno.h> +#include <limits.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/epoll.h> +#include <sys/stat.h> +#include <sys/swap.h> +#include <libudev.h> + +#include "unit.h" +#include "swap.h" +#include "load-fragment.h" +#include "load-dropin.h" +#include "unit-name.h" +#include "dbus-swap.h" +#include "special.h" +#include "bus-errors.h" +#include "exit-status.h" +#include "def.h" + +static const UnitActiveState state_translation_table[_SWAP_STATE_MAX] = { + [SWAP_DEAD] = UNIT_INACTIVE, + [SWAP_ACTIVATING] = UNIT_ACTIVATING, + [SWAP_ACTIVE] = UNIT_ACTIVE, + [SWAP_DEACTIVATING] = UNIT_DEACTIVATING, + [SWAP_ACTIVATING_SIGTERM] = UNIT_DEACTIVATING, + [SWAP_ACTIVATING_SIGKILL] = UNIT_DEACTIVATING, + [SWAP_DEACTIVATING_SIGTERM] = UNIT_DEACTIVATING, + [SWAP_DEACTIVATING_SIGKILL] = UNIT_DEACTIVATING, + [SWAP_FAILED] = UNIT_FAILED +}; + +static void swap_unset_proc_swaps(Swap *s) { + Swap *first; + + assert(s); + + if (!s->parameters_proc_swaps.what) + return; + + /* Remove this unit from the chain of swaps which share the + * same kernel swap device. */ + + first = hashmap_get(UNIT(s)->manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what); + LIST_REMOVE(Swap, same_proc_swaps, first, s); + + if (first) + hashmap_remove_and_replace(UNIT(s)->manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what, first->parameters_proc_swaps.what, first); + else + hashmap_remove(UNIT(s)->manager->swaps_by_proc_swaps, s->parameters_proc_swaps.what); + + free(s->parameters_proc_swaps.what); + s->parameters_proc_swaps.what = NULL; +} + +static void swap_init(Unit *u) { + Swap *s = SWAP(u); + + assert(s); + assert(UNIT(s)->load_state == UNIT_STUB); + + s->timeout_usec = DEFAULT_TIMEOUT_USEC; + + exec_context_init(&s->exec_context); + s->exec_context.std_output = u->manager->default_std_output; + s->exec_context.std_error = u->manager->default_std_error; + + s->parameters_etc_fstab.priority = s->parameters_proc_swaps.priority = s->parameters_fragment.priority = -1; + + s->timer_watch.type = WATCH_INVALID; + + s->control_command_id = _SWAP_EXEC_COMMAND_INVALID; + + UNIT(s)->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); + + free(s->what); + s->what = NULL; + + free(s->parameters_etc_fstab.what); + free(s->parameters_fragment.what); + s->parameters_etc_fstab.what = s->parameters_fragment.what = NULL; + + exec_context_done(&s->exec_context); + exec_command_done_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX); + s->control_command = NULL; + + swap_unwatch_control_pid(s); + + unit_unwatch_timer(u, &s->timer_watch); +} + +int swap_add_one_mount_link(Swap *s, Mount *m) { + int r; + + assert(s); + assert(m); + + if (UNIT(s)->load_state != UNIT_LOADED || + UNIT(m)->load_state != UNIT_LOADED) + return 0; + + if (is_device_path(s->what)) + return 0; + + if (!path_startswith(s->what, m->where)) + return 0; + + if ((r = unit_add_two_dependencies(UNIT(s), UNIT_AFTER, UNIT_REQUIRES, UNIT(m), true)) < 0) + return r; + + return 0; +} + +static int swap_add_mount_links(Swap *s) { + Unit *other; + int r; + + assert(s); + + LIST_FOREACH(units_by_type, other, UNIT(s)->manager->units_by_type[UNIT_MOUNT]) + if ((r = swap_add_one_mount_link(s, MOUNT(other))) < 0) + return r; + + return 0; +} + +static int swap_add_target_links(Swap *s) { + Unit *tu; + SwapParameters *p; + int r; + + assert(s); + + if (s->from_fragment) + p = &s->parameters_fragment; + else if (s->from_etc_fstab) + p = &s->parameters_etc_fstab; + else + return 0; + + if ((r = manager_load_unit(UNIT(s)->manager, SPECIAL_SWAP_TARGET, NULL, NULL, &tu)) < 0) + return r; + + if (!p->noauto && + !p->nofail && + (p->handle || UNIT(s)->manager->swap_auto) && + s->from_etc_fstab && + UNIT(s)->manager->running_as == MANAGER_SYSTEM) + if ((r = unit_add_dependency(tu, UNIT_WANTS, UNIT(s), true)) < 0) + return r; + + return unit_add_dependency(UNIT(s), UNIT_BEFORE, tu, true); +} + +static int swap_add_device_links(Swap *s) { + SwapParameters *p; + + assert(s); + + if (!s->what) + return 0; + + if (s->from_fragment) + p = &s->parameters_fragment; + else if (s->from_etc_fstab) + p = &s->parameters_etc_fstab; + else + return 0; + + if (is_device_path(s->what)) + return unit_add_node_link(UNIT(s), s->what, + !p->noauto && p->nofail && + UNIT(s)->manager->running_as == MANAGER_SYSTEM); + else + /* File based swap devices need to be ordered after + * remount-rootfs.service, since they might need a + * writable file system. */ + return unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, SPECIAL_REMOUNT_ROOTFS_SERVICE, NULL, true); +} + +static int swap_add_default_dependencies(Swap *s) { + int r; + + assert(s); + + if (UNIT(s)->manager->running_as == MANAGER_SYSTEM) { + + if ((r = unit_add_two_dependencies_by_name(UNIT(s), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true)) < 0) + return r; + } + + return 0; +} + +static int swap_verify(Swap *s) { + bool b; + char *e; + + if (UNIT(s)->load_state != UNIT_LOADED) + return 0; + + if (!(e = unit_name_from_path(s->what, ".swap"))) + return -ENOMEM; + + b = unit_has_name(UNIT(s), e); + free(e); + + if (!b) { + log_error("%s: Value of \"What\" and unit name do not match, not loading.\n", UNIT(s)->id); + return -EINVAL; + } + + if (s->exec_context.pam_name && s->exec_context.kill_mode != KILL_CONTROL_GROUP) { + log_error("%s has PAM enabled. Kill mode must be set to 'control-group'. Refusing.", UNIT(s)->id); + return -EINVAL; + } + + return 0; +} + +static int swap_load(Unit *u) { + int r; + Swap *s = SWAP(u); + + assert(s); + assert(u->load_state == UNIT_STUB); + + /* Load a .swap file */ + if ((r = unit_load_fragment_and_dropin_optional(u)) < 0) + return r; + + if (u->load_state == UNIT_LOADED) { + if ((r = unit_add_exec_dependencies(u, &s->exec_context)) < 0) + return r; + + 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_etc_fstab.what) + s->what = strdup(s->parameters_etc_fstab.what); + else if (s->parameters_proc_swaps.what) + s->what = strdup(s->parameters_proc_swaps.what); + else + s->what = unit_name_to_path(u->id); + + if (!s->what) + return -ENOMEM; + } + + path_kill_slashes(s->what); + + if (!UNIT(s)->description) + if ((r = unit_set_description(u, s->what)) < 0) + return r; + + if ((r = swap_add_device_links(s)) < 0) + return r; + + if ((r = swap_add_mount_links(s)) < 0) + return r; + + if ((r = swap_add_target_links(s)) < 0) + return r; + + if ((r = unit_add_default_cgroups(u)) < 0) + return r; + + if (UNIT(s)->default_dependencies) + if ((r = swap_add_default_dependencies(s)) < 0) + return r; + } + + return swap_verify(s); +} + +int swap_add_one( + Manager *m, + const char *what, + const char *what_proc_swaps, + int priority, + bool noauto, + bool nofail, + bool handle, + bool set_flags) { + + Unit *u = NULL; + char *e = NULL, *wp = NULL; + bool delete = false; + int r; + SwapParameters *p; + + assert(m); + assert(what); + + e = unit_name_from_path(what, ".swap"); + if (!e) + return -ENOMEM; + + u = manager_get_unit(m, e); + + if (what_proc_swaps && + u && + SWAP(u)->from_proc_swaps && + !path_equal(SWAP(u)->parameters_proc_swaps.what, what_proc_swaps)) + return -EEXIST; + + if (!u) { + delete = true; + + u = unit_new(m, sizeof(Swap)); + if (!u) { + free(e); + return -ENOMEM; + } + + r = unit_add_name(u, e); + 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; + + if (what_proc_swaps) { + Swap *first; + + p = &SWAP(u)->parameters_proc_swaps; + + if (!p->what) { + if (!(wp = strdup(what_proc_swaps))) { + r = -ENOMEM; + goto fail; + } + + if (!m->swaps_by_proc_swaps) + if (!(m->swaps_by_proc_swaps = hashmap_new(string_hash_func, string_compare_func))) { + r = -ENOMEM; + goto fail; + } + + free(p->what); + p->what = wp; + + first = hashmap_get(m->swaps_by_proc_swaps, wp); + LIST_PREPEND(Swap, same_proc_swaps, first, SWAP(u)); + + if ((r = hashmap_replace(m->swaps_by_proc_swaps, wp, first)) < 0) + goto fail; + } + + if (set_flags) { + SWAP(u)->is_active = true; + SWAP(u)->just_activated = !SWAP(u)->from_proc_swaps; + } + + SWAP(u)->from_proc_swaps = true; + + } else { + p = &SWAP(u)->parameters_etc_fstab; + + if (!(wp = strdup(what))) { + r = -ENOMEM; + goto fail; + } + + free(p->what); + p->what = wp; + + SWAP(u)->from_etc_fstab = true; + } + + p->priority = priority; + p->noauto = noauto; + p->nofail = nofail; + p->handle = handle; + + unit_add_to_dbus_queue(u); + + free(e); + + return 0; + +fail: + log_warning("Failed to load swap unit: %s", strerror(-r)); + + free(wp); + free(e); + + if (delete && u) + unit_free(u); + + return r; +} + +static int swap_process_new_swap(Manager *m, const char *device, int prio, bool set_flags) { + struct stat st; + int r = 0, k; + + assert(m); + + if (stat(device, &st) >= 0 && S_ISBLK(st.st_mode)) { + struct udev_device *d; + const char *dn; + struct udev_list_entry *item = NULL, *first = NULL; + + /* So this is a proper swap device. Create swap units + * for all names this swap device is known under */ + + if (!(d = udev_device_new_from_devnum(m->udev, 'b', st.st_rdev))) + return -ENOMEM; + + if ((dn = udev_device_get_devnode(d))) + r = swap_add_one(m, dn, device, prio, false, false, false, set_flags); + + /* Add additional units for all symlinks */ + first = udev_device_get_devlinks_list_entry(d); + udev_list_entry_foreach(item, first) { + const char *p; + + /* Don't bother with the /dev/block links */ + p = udev_list_entry_get_name(item); + + if (path_startswith(p, "/dev/block/")) + continue; + + if (stat(p, &st) >= 0) + if ((!S_ISBLK(st.st_mode)) || st.st_rdev != udev_device_get_devnum(d)) + continue; + + if ((k = swap_add_one(m, p, device, prio, false, false, false, set_flags)) < 0) + r = k; + } + + udev_device_unref(d); + } + + if ((k = swap_add_one(m, device, device, prio, false, false, false, set_flags)) < 0) + r = k; + + return r; +} + +static void swap_set_state(Swap *s, SwapState state) { + SwapState old_state; + + assert(s); + + old_state = s->state; + s->state = state; + + if (state != SWAP_ACTIVATING && + state != SWAP_ACTIVATING_SIGTERM && + state != SWAP_ACTIVATING_SIGKILL && + state != SWAP_DEACTIVATING && + state != SWAP_DEACTIVATING_SIGTERM && + state != SWAP_DEACTIVATING_SIGKILL) { + unit_unwatch_timer(UNIT(s), &s->timer_watch); + swap_unwatch_control_pid(s); + s->control_command = NULL; + s->control_command_id = _SWAP_EXEC_COMMAND_INVALID; + } + + if (state != old_state) + log_debug("%s changed %s -> %s", + UNIT(s)->id, + swap_state_to_string(old_state), + swap_state_to_string(state)); + + unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true); +} + +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) { + + if (new_state == SWAP_ACTIVATING || + new_state == SWAP_ACTIVATING_SIGTERM || + new_state == SWAP_ACTIVATING_SIGKILL || + new_state == SWAP_DEACTIVATING || + new_state == SWAP_DEACTIVATING_SIGTERM || + new_state == SWAP_DEACTIVATING_SIGKILL) { + + if (s->control_pid <= 0) + return -EBADMSG; + + if ((r = unit_watch_pid(UNIT(s), s->control_pid)) < 0) + return r; + + if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0) + return r; + } + + 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 = &s->parameters_etc_fstab; + + fprintf(f, + "%sSwap State: %s\n" + "%sResult: %s\n" + "%sWhat: %s\n" + "%sPriority: %i\n" + "%sNoAuto: %s\n" + "%sNoFail: %s\n" + "%sHandle: %s\n" + "%sFrom /etc/fstab: %s\n" + "%sFrom /proc/swaps: %s\n" + "%sFrom fragment: %s\n", + prefix, swap_state_to_string(s->state), + prefix, swap_result_to_string(s->result), + prefix, s->what, + prefix, p->priority, + prefix, yes_no(p->noauto), + prefix, yes_no(p->nofail), + prefix, yes_no(p->handle), + prefix, yes_no(s->from_etc_fstab), + prefix, yes_no(s->from_proc_swaps), + prefix, yes_no(s->from_fragment)); + + if (s->control_pid > 0) + fprintf(f, + "%sControl PID: %lu\n", + prefix, (unsigned long) s->control_pid); + + exec_context_dump(&s->exec_context, f, prefix); +} + +static int swap_spawn(Swap *s, ExecCommand *c, pid_t *_pid) { + pid_t pid; + int r; + + assert(s); + assert(c); + assert(_pid); + + if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0) + goto fail; + + if ((r = exec_spawn(c, + NULL, + &s->exec_context, + NULL, 0, + UNIT(s)->manager->environment, + true, + true, + true, + UNIT(s)->manager->confirm_spawn, + UNIT(s)->cgroup_bondings, + UNIT(s)->cgroup_attributes, + &pid)) < 0) + goto fail; + + if ((r = unit_watch_pid(UNIT(s), pid)) < 0) + /* FIXME: we need to do something here */ + goto fail; + + *_pid = pid; + + return 0; + +fail: + unit_unwatch_timer(UNIT(s), &s->timer_watch); + + return r; +} + +static void swap_enter_dead(Swap *s, SwapResult f) { + assert(s); + + if (f != SWAP_SUCCESS) + s->result = f; + + swap_set_state(s, s->result != SWAP_SUCCESS ? SWAP_FAILED : SWAP_DEAD); +} + +static void swap_enter_active(Swap *s, SwapResult f) { + assert(s); + + if (f != SWAP_SUCCESS) + s->result = f; + + swap_set_state(s, SWAP_ACTIVE); +} + +static void swap_enter_signal(Swap *s, SwapState state, SwapResult f) { + int r; + Set *pid_set = NULL; + bool wait_for_exit = false; + + assert(s); + + if (f != SWAP_SUCCESS) + s->result = f; + + if (s->exec_context.kill_mode != KILL_NONE) { + int sig = (state == SWAP_ACTIVATING_SIGTERM || + state == SWAP_DEACTIVATING_SIGTERM) ? s->exec_context.kill_signal : SIGKILL; + + if (s->control_pid > 0) { + if (kill_and_sigcont(s->control_pid, sig) < 0 && errno != ESRCH) + + log_warning("Failed to kill control process %li: %m", (long) s->control_pid); + else + wait_for_exit = true; + } + + if (s->exec_context.kill_mode == KILL_CONTROL_GROUP) { + + if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func))) { + r = -ENOMEM; + goto fail; + } + + /* Exclude the control pid from being killed via the cgroup */ + if (s->control_pid > 0) + if ((r = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0) + goto fail; + + if ((r = cgroup_bonding_kill_list(UNIT(s)->cgroup_bondings, sig, true, pid_set)) < 0) { + if (r != -EAGAIN && r != -ESRCH && r != -ENOENT) + log_warning("Failed to kill control group: %s", strerror(-r)); + } else if (r > 0) + wait_for_exit = true; + + set_free(pid_set); + pid_set = NULL; + } + } + + if (wait_for_exit) { + if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0) + goto fail; + + swap_set_state(s, state); + } else + swap_enter_dead(s, SWAP_SUCCESS); + + return; + +fail: + log_warning("%s failed to kill processes: %s", UNIT(s)->id, strerror(-r)); + + swap_enter_dead(s, SWAP_FAILURE_RESOURCES); + + if (pid_set) + set_free(pid_set); +} + +static void swap_enter_activating(Swap *s) { + int r, priority; + + assert(s); + + s->control_command_id = SWAP_EXEC_ACTIVATE; + s->control_command = s->exec_command + SWAP_EXEC_ACTIVATE; + + if (s->from_fragment) + priority = s->parameters_fragment.priority; + else if (s->from_etc_fstab) + priority = s->parameters_etc_fstab.priority; + else + priority = -1; + + if (priority >= 0) { + char p[LINE_MAX]; + + snprintf(p, sizeof(p), "%i", priority); + char_array_0(p); + + r = exec_command_set( + s->control_command, + "/sbin/swapon", + "-p", + p, + s->what, + NULL); + } else + r = exec_command_set( + s->control_command, + "/sbin/swapon", + s->what, + NULL); + + if (r < 0) + goto fail; + + swap_unwatch_control_pid(s); + + if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0) + goto fail; + + swap_set_state(s, SWAP_ACTIVATING); + + return; + +fail: + log_warning("%s failed to run 'swapon' task: %s", UNIT(s)->id, strerror(-r)); + swap_enter_dead(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; + + if ((r = exec_command_set( + s->control_command, + "/sbin/swapoff", + s->what, + NULL)) < 0) + goto fail; + + swap_unwatch_control_pid(s); + + if ((r = swap_spawn(s, s->control_command, &s->control_pid)) < 0) + goto fail; + + swap_set_state(s, SWAP_DEACTIVATING); + + return; + +fail: + log_warning("%s failed to run 'swapoff' task: %s", UNIT(s)->id, strerror(-r)); + swap_enter_active(s, SWAP_FAILURE_RESOURCES); +} + +static int swap_start(Unit *u) { + Swap *s = SWAP(u); + + assert(s); + + /* We cannot fulfill this request right now, try again later + * please! */ + + if (s->state == SWAP_DEACTIVATING || + s->state == SWAP_DEACTIVATING_SIGTERM || + s->state == SWAP_DEACTIVATING_SIGKILL || + s->state == SWAP_ACTIVATING_SIGTERM || + s->state == SWAP_ACTIVATING_SIGKILL) + return -EAGAIN; + + if (s->state == SWAP_ACTIVATING) + return 0; + + assert(s->state == SWAP_DEAD || s->state == SWAP_FAILED); + + s->result = SWAP_SUCCESS; + swap_enter_activating(s); + return 0; +} + +static int swap_stop(Unit *u) { + Swap *s = SWAP(u); + + assert(s); + + if (s->state == SWAP_DEACTIVATING || + s->state == SWAP_DEACTIVATING_SIGTERM || + s->state == SWAP_DEACTIVATING_SIGKILL || + s->state == SWAP_ACTIVATING_SIGTERM || + s->state == SWAP_ACTIVATING_SIGKILL) + return 0; + + assert(s->state == SWAP_ACTIVATING || + s->state == SWAP_ACTIVE); + + swap_enter_deactivating(s); + return 0; +} + +static int swap_serialize(Unit *u, FILE *f, FDSet *fds) { + Swap *s = SWAP(u); + + assert(s); + assert(f); + assert(fds); + + unit_serialize_item(u, f, "state", swap_state_to_string(s->state)); + unit_serialize_item(u, f, "result", swap_result_to_string(s->result)); + + if (s->control_pid > 0) + unit_serialize_item_format(u, f, "control-pid", "%lu", (unsigned long) s->control_pid); + + if (s->control_command_id >= 0) + unit_serialize_item(u, 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; + + if ((state = swap_state_from_string(value)) < 0) + log_debug("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_debug("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_debug("Failed to parse control-pid value %s", value); + else + s->control_pid = pid; + + } else if (streq(key, "control-command")) { + SwapExecCommand id; + + if ((id = swap_exec_command_from_string(value)) < 0) + log_debug("Failed to parse exec-command value %s", value); + else { + s->control_command_id = id; + s->control_command = s->exec_command + id; + } + + } else + log_debug("Unknown serialization key '%s'", key); + + return 0; +} + +static UnitActiveState swap_active_state(Unit *u) { + assert(u); + + return state_translation_table[SWAP(u)->state]; +} + +static const char *swap_sub_state_to_string(Unit *u) { + assert(u); + + return swap_state_to_string(SWAP(u)->state); +} + +static bool swap_check_gc(Unit *u) { + Swap *s = SWAP(u); + + assert(s); + + return s->from_etc_fstab || s->from_proc_swaps; +} + +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; + + s->control_pid = 0; + + if (is_clean_exit(code, status)) + 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 (f != 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; + } + + log_full(f == SWAP_SUCCESS ? LOG_DEBUG : LOG_NOTICE, + "%s swap process exited, code=%s status=%i", u->id, sigchld_code_to_string(code), status); + + switch (s->state) { + + case SWAP_ACTIVATING: + case SWAP_ACTIVATING_SIGTERM: + case SWAP_ACTIVATING_SIGKILL: + + if (f == SWAP_SUCCESS) + swap_enter_active(s, f); + else + swap_enter_dead(s, f); + break; + + case SWAP_DEACTIVATING: + case SWAP_DEACTIVATING_SIGKILL: + case SWAP_DEACTIVATING_SIGTERM: + + if (f == SWAP_SUCCESS) + swap_enter_dead(s, f); + else + swap_enter_dead(s, 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); + + /* Request a reload of /proc/swaps, so that following units + * can follow our state change */ + u->manager->request_reload = true; +} + +static void swap_timer_event(Unit *u, uint64_t elapsed, Watch *w) { + Swap *s = SWAP(u); + + assert(s); + assert(elapsed == 1); + assert(w == &s->timer_watch); + + switch (s->state) { + + case SWAP_ACTIVATING: + log_warning("%s activation timed out. Stopping.", u->id); + swap_enter_signal(s, SWAP_ACTIVATING_SIGTERM, SWAP_FAILURE_TIMEOUT); + break; + + case SWAP_DEACTIVATING: + log_warning("%s deactivation timed out. Stopping.", u->id); + swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, SWAP_FAILURE_TIMEOUT); + break; + + case SWAP_ACTIVATING_SIGTERM: + if (s->exec_context.send_sigkill) { + log_warning("%s activation timed out. Killing.", u->id); + swap_enter_signal(s, SWAP_ACTIVATING_SIGKILL, SWAP_FAILURE_TIMEOUT); + } else { + log_warning("%s activation timed out. Skipping SIGKILL. Ignoring.", u->id); + swap_enter_dead(s, SWAP_FAILURE_TIMEOUT); + } + break; + + case SWAP_DEACTIVATING_SIGTERM: + if (s->exec_context.send_sigkill) { + log_warning("%s deactivation timed out. Killing.", u->id); + swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, SWAP_FAILURE_TIMEOUT); + } else { + log_warning("%s deactivation timed out. Skipping SIGKILL. Ignoring.", u->id); + swap_enter_dead(s, SWAP_FAILURE_TIMEOUT); + } + break; + + case SWAP_ACTIVATING_SIGKILL: + case SWAP_DEACTIVATING_SIGKILL: + log_warning("%s swap process still around after SIGKILL. Ignoring.", u->id); + swap_enter_dead(s, SWAP_FAILURE_TIMEOUT); + break; + + default: + assert_not_reached("Timeout at wrong time."); + } +} + +static int swap_load_proc_swaps(Manager *m, bool set_flags) { + unsigned i; + int r = 0; + + assert(m); + + rewind(m->proc_swaps); + + (void) fscanf(m->proc_swaps, "%*s %*s %*s %*s %*s\n"); + + for (i = 1;; i++) { + char *dev = NULL, *d; + int prio = 0, k; + + if ((k = fscanf(m->proc_swaps, + "%ms " /* device/file */ + "%*s " /* type of swap */ + "%*s " /* swap size */ + "%*s " /* used */ + "%i\n", /* priority */ + &dev, &prio)) != 2) { + + if (k == EOF) + break; + + log_warning("Failed to parse /proc/swaps:%u.", i); + free(dev); + continue; + } + + d = cunescape(dev); + free(dev); + + if (!d) + return -ENOMEM; + + k = swap_process_new_swap(m, d, prio, set_flags); + free(d); + + if (k < 0) + r = k; + } + + return r; +} + +int swap_dispatch_reload(Manager *m) { + /* This function should go as soon as the kernel properly notifies us */ + + if (_likely_(!m->request_reload)) + return 0; + + m->request_reload = false; + + return swap_fd_event(m, EPOLLPRI); +} + +int swap_fd_event(Manager *m, int events) { + Unit *u; + int r; + + assert(m); + assert(events & EPOLLPRI); + + if ((r = swap_load_proc_swaps(m, true)) < 0) { + log_error("Failed to reread /proc/swaps: %s", strerror(-r)); + + /* 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) { + /* This has just been deactivated */ + + swap->from_proc_swaps = false; + swap_unset_proc_swaps(swap); + + switch (swap->state) { + + case SWAP_ACTIVE: + swap_enter_dead(swap, SWAP_SUCCESS); + break; + + default: + swap_set_state(swap, swap->state); + break; + } + + } else if (swap->just_activated) { + + /* New swap entry */ + + switch (swap->state) { + + case SWAP_DEAD: + case SWAP_FAILED: + swap_enter_active(swap, SWAP_SUCCESS); + 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 Unit *swap_following(Unit *u) { + Swap *s = SWAP(u); + Swap *other, *first = NULL; + + assert(s); + + if (streq_ptr(s->what, s->parameters_proc_swaps.what)) + return NULL; + + /* Make everybody follow the unit that's named after the swap + * device in the kernel */ + + LIST_FOREACH_AFTER(same_proc_swaps, other, s) + if (streq_ptr(other->what, other->parameters_proc_swaps.what)) + return UNIT(other); + + LIST_FOREACH_BEFORE(same_proc_swaps, other, s) { + if (streq_ptr(other->what, other->parameters_proc_swaps.what)) + return UNIT(other); + + first = other; + } + + return UNIT(first); +} + +static int swap_following_set(Unit *u, Set **_set) { + Swap *s = SWAP(u); + Swap *other; + Set *set; + int r; + + assert(s); + assert(_set); + + if (LIST_JUST_US(same_proc_swaps, s)) { + *_set = NULL; + return 0; + } + + if (!(set = set_new(NULL, NULL))) + return -ENOMEM; + + LIST_FOREACH_AFTER(same_proc_swaps, other, s) + if ((r = set_put(set, other)) < 0) + goto fail; + + LIST_FOREACH_BEFORE(same_proc_swaps, other, s) + if ((r = set_put(set, other)) < 0) + goto fail; + + *_set = set; + return 1; + +fail: + set_free(set); + return r; +} + +static void swap_shutdown(Manager *m) { + assert(m); + + if (m->proc_swaps) { + fclose(m->proc_swaps); + m->proc_swaps = NULL; + } + + hashmap_free(m->swaps_by_proc_swaps); + m->swaps_by_proc_swaps = NULL; +} + +static int swap_enumerate(Manager *m) { + int r; + struct epoll_event ev; + assert(m); + + if (!m->proc_swaps) { + if (!(m->proc_swaps = fopen("/proc/swaps", "re"))) + return (errno == ENOENT) ? 0 : -errno; + + m->swap_watch.type = WATCH_SWAP; + m->swap_watch.fd = fileno(m->proc_swaps); + + zero(ev); + ev.events = EPOLLPRI; + ev.data.ptr = &m->swap_watch; + + if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->swap_watch.fd, &ev) < 0) + return -errno; + } + + /* We rely on mount.c to load /etc/fstab for us */ + + if ((r = swap_load_proc_swaps(m, false)) < 0) + swap_shutdown(m); + + 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; +} + +static int swap_kill(Unit *u, KillWho who, KillMode mode, int signo, DBusError *error) { + Swap *s = SWAP(u); + int r = 0; + Set *pid_set = NULL; + + assert(s); + + if (who == KILL_MAIN) { + dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "Swap units have no main processes"); + return -ESRCH; + } + + if (s->control_pid <= 0 && who == KILL_CONTROL) { + dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "No control process to kill"); + return -ESRCH; + } + + if (who == KILL_CONTROL || who == KILL_ALL) + if (s->control_pid > 0) + if (kill(s->control_pid, signo) < 0) + r = -errno; + + if (who == KILL_ALL && mode == KILL_CONTROL_GROUP) { + int q; + + if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func))) + return -ENOMEM; + + /* Exclude the control pid from being killed via the cgroup */ + if (s->control_pid > 0) + if ((q = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0) { + r = q; + goto finish; + } + + if ((q = cgroup_bonding_kill_list(UNIT(s)->cgroup_bondings, signo, false, pid_set)) < 0) + if (q != -EAGAIN && q != -ESRCH && q != -ENOENT) + r = q; + } + +finish: + if (pid_set) + set_free(pid_set); + + return r; +} + +static const char* const swap_state_table[_SWAP_STATE_MAX] = { + [SWAP_DEAD] = "dead", + [SWAP_ACTIVATING] = "activating", + [SWAP_ACTIVE] = "active", + [SWAP_DEACTIVATING] = "deactivating", + [SWAP_ACTIVATING_SIGTERM] = "activating-sigterm", + [SWAP_ACTIVATING_SIGKILL] = "activating-sigkill", + [SWAP_DEACTIVATING_SIGTERM] = "deactivating-sigterm", + [SWAP_DEACTIVATING_SIGKILL] = "deactivating-sigkill", + [SWAP_FAILED] = "failed" +}; + +DEFINE_STRING_TABLE_LOOKUP(swap_state, SwapState); + +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" +}; + +DEFINE_STRING_TABLE_LOOKUP(swap_result, SwapResult); + +const UnitVTable swap_vtable = { + .suffix = ".swap", + .object_size = sizeof(Swap), + .sections = + "Unit\0" + "Swap\0" + "Install\0", + + .no_alias = true, + .no_instances = true, + .show_status = 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, + + .serialize = swap_serialize, + .deserialize_item = swap_deserialize_item, + + .active_state = swap_active_state, + .sub_state_to_string = swap_sub_state_to_string, + + .check_gc = swap_check_gc, + + .sigchld_event = swap_sigchld_event, + .timer_event = swap_timer_event, + + .reset_failed = swap_reset_failed, + + .bus_interface = "org.freedesktop.systemd1.Swap", + .bus_message_handler = bus_swap_message_handler, + .bus_invalidating_properties = bus_swap_invalidating_properties, + + .following = swap_following, + .following_set = swap_following_set, + + .enumerate = swap_enumerate, + .shutdown = swap_shutdown +}; |