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Systemd/src/core/swap.c
Lennart Poettering 37cf8fee46 core: if two start jobs for the same swap device node are queued, only dispatch one of them at a time 
If two start jobs for two seperate .swap device nodes are queued, which
then turns out to be referring to the same device node, refuse
dispatching more than one of them at the same time.

This should solve an issue when the same swap partition is found via GPT
auto-discovery and via /etc/fstab, where one uses a symlink path, and
the other the raw devce node. So far we might have ended up invoking
mkswap on the same node at the very same time with the two device node
names.

With this change only one mkswap should be executed at a time. THis
mkswap should have immediate effect on the other swap unit, due to the
state in /proc/swaps changing, and thus suppressing actual invocation of
the second mkswap.

http://lists.freedesktop.org/archives/systemd-devel/2015-January/027314.html
2015-01-28 00:38:38 +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 <limits.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/epoll.h>
#include <sys/stat.h>
#include <sys/swap.h>
#include <libudev.h>
#include "unit.h"
#include "swap.h"
#include "load-fragment.h"
#include "load-dropin.h"
#include "unit-name.h"
#include "dbus-swap.h"
#include "special.h"
#include "bus-common-errors.h"
#include "exit-status.h"
#include "def.h"
#include "path-util.h"
#include "virt.h"
#include "udev-util.h"
#include "fstab-util.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;
free(s->parameters_proc_swaps.what);
s->parameters_proc_swaps.what = NULL;
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);
free(s->devnode);
s->devnode = NULL;
}
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);
free(s->what);
s->what = NULL;
free(s->parameters_fragment.what);
s->parameters_fragment.what = NULL;
free(s->parameters_fragment.options);
s->parameters_fragment.options = NULL;
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);
}
return 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);
}
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 == SYSTEMD_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)->manager->running_as != SYSTEMD_SYSTEM)
return 0;
if (detect_container(NULL) > 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) {
bool b;
_cleanup_free_ char *e = NULL;
if (UNIT(s)->load_state != UNIT_LOADED)
return 0;
e = unit_name_from_path(s->what, ".swap");
if (!e)
return log_oom();
b = unit_has_name(UNIT(s), e);
if (!b) {
log_unit_error(UNIT(s)->id, "%s: Value of \"What\" and unit name do not match, not loading.", UNIT(s)->id);
return -EINVAL;
}
if (s->exec_context.pam_name && s->kill_context.kill_mode != KILL_CONTROL_GROUP) {
log_unit_error(UNIT(s)->id, "%s has PAM enabled. Kill mode must be set to 'control-group'. Refusing to load.", UNIT(s)->id);
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
s->what = unit_name_to_path(u->id);
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_add_default_slice(u, &s->cgroup_context);
if (r < 0)
return r;
if (UNIT(s)->default_dependencies) {
r = swap_add_default_dependencies(s);
if (r < 0)
return r;
}
}
return swap_verify(s);
}
static int swap_add_one(
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);
e = unit_name_from_path(what, ".swap");
if (!e)
return log_oom();
u = manager_get_unit(m, e);
if (u &&
SWAP(u)->from_proc_swaps &&
!path_equal(SWAP(u)->parameters_proc_swaps.what, what_proc_swaps))
return -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 = log_oom();
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(e, r, "Failed to load swap unit: %m");
if (delete && u)
unit_free(u);
return r;
}
static int swap_process_new_swap(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_add_one(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_add_one(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_add_one(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)->id,
"%s changed %s -> %s",
UNIT(s)->id,
swap_state_to_string(old_state),
swap_state_to_string(state));
unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
/* 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 (new_state == SWAP_ACTIVATING ||
new_state == SWAP_ACTIVATING_SIGTERM ||
new_state == SWAP_ACTIVATING_SIGKILL ||
new_state == SWAP_ACTIVATING_DONE ||
new_state == SWAP_DEACTIVATING ||
new_state == SWAP_DEACTIVATING_SIGTERM ||
new_state == SWAP_DEACTIVATING_SIGKILL) {
if (s->control_pid <= 0)
return -EBADMSG;
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,
};
assert(s);
assert(c);
assert(_pid);
unit_realize_cgroup(UNIT(s));
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);
exec_params.unit_id = UNIT(s)->id;
r = exec_spawn(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)->id, r, "%s failed to kill processes: %m", UNIT(s)->id);
swap_enter_dead(s, SWAP_FAILURE_RESOURCES);
}
static void swap_enter_activating(Swap *s) {
_cleanup_free_ char *discard = NULL;
int r, priority = -1;
assert(s);
s->control_command_id = SWAP_EXEC_ACTIVATE;
s->control_command = s->exec_command + SWAP_EXEC_ACTIVATE;
if (s->from_fragment) {
fstab_filter_options(s->parameters_fragment.options, "discard\0",
NULL, &discard, NULL);
priority = s->parameters_fragment.priority;
if (priority < 0)
fstab_find_pri(s->parameters_fragment.options, &priority);
}
r = exec_command_set(s->control_command, "/sbin/swapon", NULL);
if (r < 0)
goto fail;
if (priority >= 0) {
char p[DECIMAL_STR_MAX(int)];
sprintf(p, "%i", priority);
r = exec_command_append(s->control_command, "-p", p, NULL);
if (r < 0)
goto fail;
}
if (discard && !streq(discard, "none")) {
const char *discard_arg;
if (streq(discard, "all"))
discard_arg = "--discard";
else
discard_arg = strappenda("--discard=", discard);
r = exec_command_append(s->control_command, discard_arg, 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)->id, r, "%s failed to run 'swapon' task: %m", UNIT(s)->id);
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)->id, r, "%s failed to run 'swapoff' task: %m", UNIT(s)->id);
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(NULL) > 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;
swap_enter_activating(s);
return 0;
}
static int swap_stop(Unit *u) {
Swap *s = SWAP(u);
assert(s);
if (s->state == SWAP_DEACTIVATING ||
s->state == SWAP_DEACTIVATING_SIGTERM ||
s->state == SWAP_DEACTIVATING_SIGKILL ||
s->state == SWAP_ACTIVATING_SIGTERM ||
s->state == SWAP_ACTIVATING_SIGKILL)
return 0;
assert(s->state == SWAP_ACTIVATING ||
s->state == SWAP_ACTIVATING_DONE ||
s->state == SWAP_ACTIVE);
if (detect_container(NULL) > 0)
return -EPERM;
swap_enter_deactivating(s);
return 0;
}
static int swap_serialize(Unit *u, FILE *f, FDSet *fds) {
Swap *s = SWAP(u);
assert(s);
assert(f);
assert(fds);
unit_serialize_item(u, f, "state", swap_state_to_string(s->state));
unit_serialize_item(u, f, "result", swap_result_to_string(s->result));
if (s->control_pid > 0)
unit_serialize_item_format(u, f, "control-pid", 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->id, "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->id, "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->id, "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->id, "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->id, "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->id,
f == SWAP_SUCCESS ? LOG_DEBUG : LOG_NOTICE,
"%s swap process exited, code=%s status=%i",
u->id, sigchld_code_to_string(code), status);
switch (s->state) {
case SWAP_ACTIVATING:
case SWAP_ACTIVATING_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)->id, "%s activation timed out. Stopping.", UNIT(s)->id);
swap_enter_signal(s, SWAP_ACTIVATING_SIGTERM, SWAP_FAILURE_TIMEOUT);
break;
case SWAP_DEACTIVATING:
log_unit_warning(UNIT(s)->id, "%s deactivation timed out. Stopping.", UNIT(s)->id);
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)->id, "%s activation timed out. Killing.", UNIT(s)->id);
swap_enter_signal(s, SWAP_ACTIVATING_SIGKILL, SWAP_FAILURE_TIMEOUT);
} else {
log_unit_warning(UNIT(s)->id, "%s activation timed out. Skipping SIGKILL. Ignoring.", UNIT(s)->id);
swap_enter_dead(s, SWAP_FAILURE_TIMEOUT);
}
break;
case SWAP_DEACTIVATING_SIGTERM:
if (s->kill_context.send_sigkill) {
log_unit_warning(UNIT(s)->id, "%s deactivation timed out. Killing.", UNIT(s)->id);
swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, SWAP_FAILURE_TIMEOUT);
} else {
log_unit_warning(UNIT(s)->id, "%s deactivation timed out. Skipping SIGKILL. Ignoring.", UNIT(s)->id);
swap_enter_dead(s, SWAP_FAILURE_TIMEOUT);
}
break;
case SWAP_ACTIVATING_SIGKILL:
case SWAP_DEACTIVATING_SIGKILL:
log_unit_warning(UNIT(s)->id, "%s swap process still around after SIGKILL. Ignoring.", UNIT(s)->id);
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;
}
d = cunescape(dev);
if (!d)
return -ENOMEM;
k = swap_process_new_swap(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;
}
} 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);
if (m->proc_swaps) {
fclose(m->proc_swaps);
m->proc_swaps = NULL;
}
hashmap_free(m->swaps_by_devnode);
m->swaps_by_devnode = NULL;
}
static int swap_enumerate(Manager *m) {
int r;
assert(m);
if (!m->proc_swaps) {
m->proc_swaps = fopen("/proc/swaps", "re");
if (!m->proc_swaps)
return errno == ENOENT ? 0 : -errno;
r = sd_event_add_io(m->event, &m->swap_event_source, fileno(m->proc_swaps), EPOLLPRI, swap_dispatch_io, m);
if (r < 0)
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)
goto fail;
}
r = swap_load_proc_swaps(m, false);
if (r < 0)
goto fail;
return 0;
fail:
swap_shutdown(m);
return r;
}
int swap_process_new_device(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;
e = unit_name_from_path(dn, ".swap");
if (!e)
return -ENOMEM;
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;
n = unit_name_from_path(udev_list_entry_get_name(item), ".swap");
if (!n)
return -ENOMEM;
s = hashmap_get(m->units, n);
if (s) {
int q;
q = swap_set_devnode(s, dn);
if (q < 0)
r = q;
}
}
return r;
}
int swap_process_removed_device(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(Manager *m) {
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(NULL) <= 0;
return supported;
}
static const char* const swap_state_table[_SWAP_STATE_MAX] = {
[SWAP_DEAD] = "dead",
[SWAP_ACTIVATING] = "activating",
[SWAP_ACTIVATING_DONE] = "activating-done",
[SWAP_ACTIVE] = "active",
[SWAP_DEACTIVATING] = "deactivating",
[SWAP_ACTIVATING_SIGTERM] = "activating-sigterm",
[SWAP_ACTIVATING_SIGKILL] = "activating-sigkill",
[SWAP_DEACTIVATING_SIGTERM] = "deactivating-sigterm",
[SWAP_DEACTIVATING_SIGKILL] = "deactivating-sigkill",
[SWAP_FAILED] = "failed"
};
DEFINE_STRING_TABLE_LOOKUP(swap_state, SwapState);
static const char* const swap_exec_command_table[_SWAP_EXEC_COMMAND_MAX] = {
[SWAP_EXEC_ACTIVATE] = "ExecActivate",
[SWAP_EXEC_DEACTIVATE] = "ExecDeactivate",
};
DEFINE_STRING_TABLE_LOOKUP(swap_exec_command, SwapExecCommand);
static const char* const swap_result_table[_SWAP_RESULT_MAX] = {
[SWAP_SUCCESS] = "success",
[SWAP_FAILURE_RESOURCES] = "resources",
[SWAP_FAILURE_TIMEOUT] = "timeout",
[SWAP_FAILURE_EXIT_CODE] = "exit-code",
[SWAP_FAILURE_SIGNAL] = "signal",
[SWAP_FAILURE_CORE_DUMP] = "core-dump"
};
DEFINE_STRING_TABLE_LOOKUP(swap_result, SwapResult);
const UnitVTable swap_vtable = {
.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_interface = "org.freedesktop.systemd1.Swap",
.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_DEPENDENCY] = "Dependency failed for %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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