#include <errno.h>

#include <sys/epoll.h>

#include <sys/stat.h>

#include <unistd.h>

#include "libudev.h"

#include "alloc-util.h"

#include "dbus-swap.h"

#include "escape.h"

#include "exit-status.h"

#include "fd-util.h"

#include "formats-util.h"

#include "fstab-util.h"

#include "parse-util.h"

#include "path-util.h"

#include "process-util.h"

#include "special.h"

#include "string-table.h"

#include "string-util.h"

#include "swap.h"

#include "udev-util.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_ACTIVATING_SIGTERM] = UNIT_DEACTIVATING,

[SWAP_ACTIVATING_SIGKILL] = UNIT_DEACTIVATING,

[SWAP_DEACTIVATING_SIGTERM] = UNIT_DEACTIVATING,

[SWAP_DEACTIVATING_SIGKILL] = UNIT_DEACTIVATING,

[SWAP_FAILED] = UNIT_FAILED

};

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 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, &string_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->parameters_proc_swaps.priority = s->parameters_fragment.priority = -1;

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);

exec_command_done_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX);

s->control_command = NULL;

swap_unwatch_control_pid(s);

s->timer_event_source = sd_event_source_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 int swap_add_device_links(Swap *s) {

assert(s);

if (!s->what)

return 0;

if (!s->from_fragment)

return 0;

if (is_device_path(s->what))

return unit_add_node_link(UNIT(s), s->what, UNIT(s)->manager->running_as == MANAGER_SYSTEM, UNIT_BINDS_TO);

else

/* File based swap devices need to be ordered after

return unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, SPECIAL_REMOUNT_FS_SERVICE, NULL, true);

}

static int swap_add_default_dependencies(Swap *s) {

int r;

assert(s);

if (!UNIT(s)->default_dependencies)

return 0;

if (UNIT(s)->manager->running_as != MANAGER_SYSTEM)

return 0;

if (detect_container() > 0)

return 0;

/* swap units generated for the swap dev links are missing the

r = unit_add_dependency_by_name(UNIT(s), UNIT_BEFORE, SPECIAL_SWAP_TARGET, NULL, true);

if (r < 0)

return r;

return unit_add_two_dependencies_by_name(UNIT(s), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true);

}

static int swap_verify(Swap *s) {

_cleanup_free_ char *e = NULL;

int r;

if (UNIT(s)->load_state != UNIT_LOADED)

return 0;

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)) {

log_unit_error(UNIT(s), "Value of What= and unit name do not match, not loading.");

return -EINVAL;

}

if (s->exec_context.pam_name && s->kill_context.kill_mode != KILL_CONTROL_GROUP) {

log_unit_error(UNIT(s), "Unit has PAM enabled. Kill mode must be set to 'control-group'. Refusing to load.");

return -EINVAL;

}

return 0;

}

static int swap_load_devnode(Swap *s) {

_cleanup_udev_device_unref_ struct udev_device *d = NULL;

struct stat st;

const char *p;

assert(s);

if (stat(s->what, &st) < 0 || !S_ISBLK(st.st_mode))

return 0;

d = udev_device_new_from_devnum(UNIT(s)->manager->udev, 'b', st.st_rdev);

if (!d)

return 0;

p = udev_device_get_devnode(d);

if (!p)

return 0;

return swap_set_devnode(s, p);

}

static int swap_load(Unit *u) {

int r;

Swap *s = SWAP(u);

assert(s);

assert(u->load_state == UNIT_STUB);

/* Load a .swap file */

r = unit_load_fragment_and_dropin_optional(u);

if (r < 0)

return r;

if (u->load_state == UNIT_LOADED) {

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(u->id, &s->what);

if (r < 0)

return r;

}

if (!s->what)

return -ENOMEM;

}

path_kill_slashes(s->what);

if (!UNIT(s)->description) {

r = unit_set_description(u, s->what);

if (r < 0)

return r;

}

r = unit_require_mounts_for(UNIT(s), s->what);

if (r < 0)

return r;

r = swap_add_device_links(s);

if (r < 0)

return r;

r = swap_load_devnode(s);

if (r < 0)

return r;

r = unit_patch_contexts(u);

if (r < 0)

return r;

r = unit_add_exec_dependencies(u, &s->exec_context);

if (r < 0)

return r;

r = unit_set_default_slice(u);

if (r < 0)

return r;

r = swap_add_default_dependencies(s);

if (r < 0)

return r;

}

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)) {

log_error("Swap %s appeared twice with different device paths %s and %s", e, SWAP(u)->parameters_proc_swaps.what, what_proc_swaps);

return -EEXIST;

}

if (!u) {

delete = true;

u = unit_new(m, sizeof(Swap));

if (!u)

return log_oom();

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;

p = &SWAP(u)->parameters_proc_swaps;

if (!p->what) {

p->what = strdup(what_proc_swaps);

if (!p->what) {

r = -ENOMEM;

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;

p->priority = priority;

unit_add_to_dbus_queue(u);

return 0;

fail:

log_unit_warning_errno(u, r, "Failed to load swap unit: %m");

if (delete && u)

unit_free(u);

return r;

}

static int swap_process_new(Manager *m, const char *device, int prio, bool set_flags) {

_cleanup_udev_device_unref_ struct udev_device *d = NULL;

struct udev_list_entry *item = NULL, *first = NULL;

const char *dn;

struct stat st;

int r;

assert(m);

r = swap_setup_unit(m, device, device, prio, set_flags);

if (r < 0)

return r;

/* If this is a block device, then let's add duplicates for

if (stat(device, &st) < 0 || !S_ISBLK(st.st_mode))

return 0;

d = udev_device_new_from_devnum(m->udev, 'b', st.st_rdev);

if (!d)

return 0;

/* Add the main device node */

dn = udev_device_get_devnode(d);

if (dn && !streq(dn, device))

swap_setup_unit(m, dn, device, prio, 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 (streq(p, device))

continue;

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;

swap_setup_unit(m, p, device, prio, set_flags);

}

return r;

}

static void swap_set_state(Swap *s, SwapState state) {

SwapState old_state;

Swap *other;

assert(s);

old_state = s->state;

s->state = state;

if (state != SWAP_ACTIVATING &&

state != SWAP_ACTIVATING_SIGTERM &&

state != SWAP_ACTIVATING_SIGKILL &&

state != SWAP_ACTIVATING_DONE &&

state != SWAP_DEACTIVATING &&

state != SWAP_DEACTIVATING_SIGTERM &&

state != SWAP_DEACTIVATING_SIGKILL) {

s->timer_event_source = sd_event_source_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], true);

/* If there other units for the same device node have a job

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) &&

IN_SET(new_state,

SWAP_ACTIVATING,

SWAP_ACTIVATING_SIGTERM,

SWAP_ACTIVATING_SIGKILL,

SWAP_ACTIVATING_DONE,

SWAP_DEACTIVATING,

SWAP_DEACTIVATING_SIGTERM,

SWAP_DEACTIVATING_SIGKILL)) {

r = unit_watch_pid(UNIT(s), s->control_pid);

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;

}

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"

"%sWhat: %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, yes_no(s->from_proc_swaps),

prefix, yes_no(s->from_fragment));

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));

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);

}

static int swap_spawn(Swap *s, ExecCommand *c, pid_t *_pid) {

pid_t pid;

int r;

ExecParameters exec_params = {

.apply_permissions = true,

.apply_chroot = true,

.apply_tty_stdin = true,

.bus_endpoint_fd = -1,

.stdin_fd = -1,

.stdout_fd = -1,

.stderr_fd = -1,

};

assert(s);

assert(c);

assert(_pid);

(void) unit_realize_cgroup(UNIT(s));

if (s->reset_cpu_usage) {

(void) unit_reset_cpu_usage(UNIT(s));

s->reset_cpu_usage = false;

}

r = unit_setup_exec_runtime(UNIT(s));

if (r < 0)

goto fail;

r = swap_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_usec));

if (r < 0)

goto fail;

exec_params.environment = UNIT(s)->manager->environment;

exec_params.confirm_spawn = UNIT(s)->manager->confirm_spawn;

exec_params.cgroup_supported = UNIT(s)->manager->cgroup_supported;

exec_params.cgroup_path = UNIT(s)->cgroup_path;

exec_params.cgroup_delegate = s->cgroup_context.delegate;

exec_params.runtime_prefix = manager_get_runtime_prefix(UNIT(s)->manager);

r = exec_spawn(UNIT(s),

c,

&s->exec_context,

&exec_params,

s->exec_runtime,

&pid);

if (r < 0)

goto fail;

r = unit_watch_pid(UNIT(s), pid);

if (r < 0)

/* FIXME: we need to do something here */

goto fail;

*_pid = pid;

return 0;

fail:

s->timer_event_source = sd_event_source_unref(s->timer_event_source);

return r;

}

static void swap_enter_dead(Swap *s, SwapResult f) {

assert(s);

if (f != SWAP_SUCCESS)

s->result = f;

exec_runtime_destroy(s->exec_runtime);

s->exec_runtime = exec_runtime_unref(s->exec_runtime);

exec_context_destroy_runtime_directory(&s->exec_context, manager_get_runtime_prefix(UNIT(s)->manager));

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;

assert(s);

if (f != SWAP_SUCCESS)

s->result = f;

r = unit_kill_context(

UNIT(s),

&s->kill_context,

(state != SWAP_ACTIVATING_SIGTERM && state != SWAP_DEACTIVATING_SIGTERM) ?

KILL_KILL : KILL_TERMINATE,

-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_ACTIVATING_SIGTERM)

swap_enter_signal(s, SWAP_ACTIVATING_SIGKILL, SWAP_SUCCESS);

else if (state == SWAP_DEACTIVATING_SIGTERM)

swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, SWAP_SUCCESS);

else

swap_enter_dead(s, SWAP_SUCCESS);

return;

fail:

log_unit_warning_errno(UNIT(s), r, "Failed to kill processes: %m");

swap_enter_dead(s, SWAP_FAILURE_RESOURCES);

}

static void swap_enter_activating(Swap *s) {

_cleanup_free_ char *opts = NULL;

int r;

assert(s);

s->control_command_id = SWAP_EXEC_ACTIVATE;

s->control_command = s->exec_command + SWAP_EXEC_ACTIVATE;

if (s->from_fragment) {

int priority = -1;

r = fstab_find_pri(s->parameters_fragment.options, &priority);

if (r < 0)

log_warning_errno(r, "Failed to parse swap priority \"%s\", ignoring: %m", s->parameters_fragment.options);

else if (r == 1 && s->parameters_fragment.priority >= 0)

log_warning("Duplicate swap priority configuration by Priority and Options fields.");

if (r <= 0 && s->parameters_fragment.priority >= 0) {

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)

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(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_active(s, SWAP_FAILURE_RESOURCES);

}

static int swap_start(Unit *u) {

Swap *s = SWAP(u), *other;

assert(s);

/* We cannot fulfill this request right now, try again later

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);

if (detect_container() > 0)

return -EPERM;

/* If there's a job for another swap unit for the same node

LIST_FOREACH_OTHERS(same_devnode, other, s)

if (UNIT(other)->job && UNIT(other)->job->state == JOB_RUNNING)

return -EAGAIN;

s->result = SWAP_SUCCESS;

s->reset_cpu_usage = true;

swap_enter_activating(s);

return 1;

}

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_ACTIVATING_DONE ||

s->state == SWAP_ACTIVE);

if (detect_container() > 0)

return -EPERM;

swap_enter_deactivating(s);

return 1;

}

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", PID_FMT, 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;

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;

}

_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_check_gc(Unit *u) {

Swap *s = SWAP(u);

assert(s);

return 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, 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 (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_unit_full(u, f == SWAP_SUCCESS ? LOG_DEBUG : LOG_NOTICE, 0,

"Swap process exited, code=%s status=%i", sigchld_code_to_string(code), status);

switch (s->state) {

case SWAP_ACTIVATING:

case SWAP_ACTIVATING_DONE:

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:

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);

}

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_ACTIVATING_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_ACTIVATING_SIGTERM:

if (s->kill_context.send_sigkill) {

log_unit_warning(UNIT(s), "Activation timed out. Killing.");

swap_enter_signal(s, SWAP_ACTIVATING_SIGKILL, SWAP_FAILURE_TIMEOUT);

} else {

log_unit_warning(UNIT(s), "Activation timed out. Skipping SIGKILL. Ignoring.");

swap_enter_dead(s, SWAP_FAILURE_TIMEOUT);

}

break;

case SWAP_DEACTIVATING_SIGTERM:

if (s->kill_context.send_sigkill) {

log_unit_warning(UNIT(s), "Deactivation timed out. Killing.");

swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, SWAP_FAILURE_TIMEOUT);

} else {

log_unit_warning(UNIT(s), "Deactivation timed out. Skipping SIGKILL. Ignoring.");

swap_enter_dead(s, SWAP_FAILURE_TIMEOUT);

}

break;

case SWAP_ACTIVATING_SIGKILL:

case SWAP_DEACTIVATING_SIGKILL:

log_unit_warning(UNIT(s), "Swap process still around after SIGKILL. Ignoring.");

swap_enter_dead(s, SWAP_FAILURE_TIMEOUT);

break;

default:

assert_not_reached("Timeout at wrong time.");

}

return 0;

}

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++) {

_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;

}

if (cunescape(dev, UNESCAPE_RELAX, &d) < 0)

return log_oom();

device_found_node(m, d, true, DEVICE_FOUND_SWAP, set_flags);

k = swap_process_new(m, d, prio, set_flags);

if (k < 0)

r = k;

}

return r;

}

static int swap_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) {

Manager *m = userdata;

Unit *u;

int r;

assert(m);

assert(revents & EPOLLPRI);

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) {

/* This has just been deactivated */

swap_unset_proc_swaps(swap);

switch (swap->state) {

case SWAP_ACTIVE:

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, false, DEVICE_FOUND_SWAP, true);

} else if (swap->just_activated) {

/* New swap entry */

switch (swap->state) {

case SWAP_DEAD:

case SWAP_FAILED:

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

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 the user configured the swap through /etc/fstab or

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

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;

Set *set;

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)

goto fail;

}

*_set = set;

return 1;

fail:

set_free(set);

return r;

}

static void swap_shutdown(Manager *m) {

assert(m);

m->swap_event_source = sd_event_source_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("Not swap enabled, skipping enumeration");

else

log_error_errno(errno, "Failed to open /proc/swaps: %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

r = sd_event_source_set_priority(m->swap_event_source, -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, struct udev_device *dev) {

struct udev_list_entry *item = NULL, *first = NULL;

_cleanup_free_ char *e = NULL;

const char *dn;

Swap *s;

int r = 0;

assert(m);

assert(dev);

dn = udev_device_get_devnode(dev);

if (!dn)

return 0;

r = unit_name_from_path(dn, ".swap", &e);

if (r < 0)

return r;

s = hashmap_get(m->units, e);

if (s)

r = swap_set_devnode(s, dn);

first = udev_device_get_devlinks_list_entry(dev);

udev_list_entry_foreach(item, first) {

_cleanup_free_ char *n = NULL;

int q;

q = unit_name_from_path(udev_list_entry_get_name(item), ".swap", &n);

if (q < 0)

return q;

s = hashmap_get(m->units, n);

if (s) {

q = swap_set_devnode(s, dn);

if (q < 0)

r = q;

}

}

return r;

}

int swap_process_device_remove(Manager *m, struct udev_device *dev) {

const char *dn;

int r = 0;

Swap *s;

dn = udev_device_get_devnode(dev);

if (!dn)

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;

}

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, uint64_t *timeout) {

Swap *s = SWAP(u);

int r;

if (!s->timer_event_source)

return 0;

r = sd_event_source_get_time(s->timer_event_source, timeout);

if (r < 0)

return r;

return 1;

}

static bool swap_supported(void) {

static int supported = -1;

/* If swap support is not available in the kernel, or we are

if (supported < 0)

supported =

access("/proc/swaps", F_OK) >= 0 &&

detect_container() <= 0;

return supported;

}

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 = {

.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),

.sections =

"Unit\0"

"Swap\0"

"Install\0",

.private_section = "Swap",

.no_alias = true,

.no_instances = 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,

.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,

.check_gc = swap_check_gc,

.sigchld_event = swap_sigchld_event,

.reset_failed = swap_reset_failed,

.bus_vtable = bus_swap_vtable,

.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.",

},

},

};