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Systemd/src/core/swap.c
Franck Bui 8bf23dc757 make sure all swap units are ordered before the swap target 
When shutting down the system, the swap devices can be disabled long
time before the swap target is stopped. They're actually the first
units systemd turns off on my system.

This is incorrect and due to swap devices having multiple associated
swap unit files. The main one is usually created by the fstab
generator and is used to start the swap device.

Once done, systemd creates some 'alias' units for the same swap
device, one for each swap dev link. But those units are missing an
ordering dependencies which was created by the fstab generator for the
main swap unit.

Therefore during shutdown those 'alias' units can be stopped at
anytime before unmount.target target.

This patch makes sure that all swap units are stopped after the
swap.target target.
2015-11-23 11:23:44 +01:00

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/*-*- 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 Lesser General Public License as published by
the Free Software Foundation; either version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#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) {
int r;
assert(s);
if (s->timeout_usec <= 0) {
s->timer_event_source = sd_event_source_unref(s->timer_event_source);
return 0;
}
if (s->timer_event_source) {
r = sd_event_source_set_time(s->timer_event_source, now(CLOCK_MONOTONIC) + s->timeout_usec);
if (r < 0)
return r;
return sd_event_source_set_enabled(s->timer_event_source, SD_EVENT_ONESHOT);
}
r = sd_event_add_time(
UNIT(s)->manager->event,
&s->timer_event_source,
CLOCK_MONOTONIC,
now(CLOCK_MONOTONIC) + s->timeout_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);
else
/* 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, 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
* ordering dep against the swap target. */
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
* all other names of this block device */
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
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) &&
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);
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);
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);
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
* 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);
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;
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
* 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 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;
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
* we always get the events from /proc/swaps before
* the SIGCHLD of /sbin/swapon. */
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
* 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 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.",
},
},
};
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