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fb5c8184a9
systemd/src/core/swap.c
Lennart Poettering 4c9ea260ae core: simplify things a bit by checking default_dependencies boolean in callee, not caller 
It's nicer to hide the check away in the various
xyz_add_default_dependencies() calls, rather than making it explicit in
the caller, and thus require deeper nesing.
2015-11-11 20:42:39 +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) {
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;
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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