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-rw-r--r--src/core/swap.c1555
1 files changed, 1555 insertions, 0 deletions
diff --git a/src/core/swap.c b/src/core/swap.c
new file mode 100644
index 0000000..2d8463b
--- /dev/null
+++ b/src/core/swap.c
@@ -0,0 +1,1555 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <sys/epoll.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "sd-device.h"
+
+#include "alloc-util.h"
+#include "dbus-swap.h"
+#include "dbus-unit.h"
+#include "device-private.h"
+#include "device-util.h"
+#include "device.h"
+#include "escape.h"
+#include "exit-status.h"
+#include "fd-util.h"
+#include "format-util.h"
+#include "fstab-util.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "serialize.h"
+#include "special.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "swap.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_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 bool SWAP_STATE_WITH_PROCESS(SwapState state) {
+ return IN_SET(state,
+ SWAP_ACTIVATING,
+ SWAP_ACTIVATING_DONE,
+ SWAP_DEACTIVATING,
+ SWAP_DEACTIVATING_SIGTERM,
+ SWAP_DEACTIVATING_SIGKILL);
+}
+
+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, &path_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, false);
+ exec_command_done_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX);
+ s->control_command = NULL;
+
+ dynamic_creds_unref(&s->dynamic_creds);
+
+ swap_unwatch_control_pid(s);
+
+ s->timer_event_source = sd_event_source_unref(s->timer_event_source);
+}
+
+static int swap_arm_timer(Swap *s, usec_t usec) {
+ int r;
+
+ assert(s);
+
+ if (s->timer_event_source) {
+ r = sd_event_source_set_time(s->timer_event_source, usec);
+ if (r < 0)
+ return r;
+
+ return sd_event_source_set_enabled(s->timer_event_source, SD_EVENT_ONESHOT);
+ }
+
+ if (usec == USEC_INFINITY)
+ return 0;
+
+ r = sd_event_add_time(
+ UNIT(s)->manager->event,
+ &s->timer_event_source,
+ CLOCK_MONOTONIC,
+ usec, 0,
+ swap_dispatch_timer, s);
+ if (r < 0)
+ return r;
+
+ (void) sd_event_source_set_description(s->timer_event_source, "swap-timer");
+
+ return 0;
+}
+
+static int swap_add_device_dependencies(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_dependency(UNIT(s), s->what, MANAGER_IS_SYSTEM(UNIT(s)->manager), UNIT_BINDS_TO, UNIT_DEPENDENCY_FILE);
+ 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, true, UNIT_DEPENDENCY_FILE);
+}
+
+static int swap_add_default_dependencies(Swap *s) {
+ int r;
+
+ assert(s);
+
+ if (!UNIT(s)->default_dependencies)
+ return 0;
+
+ if (!MANAGER_IS_SYSTEM(UNIT(s)->manager))
+ 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, true, UNIT_DEPENDENCY_DEFAULT);
+ if (r < 0)
+ return r;
+
+ return unit_add_two_dependencies_by_name(UNIT(s), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
+}
+
+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 -ENOEXEC;
+ }
+
+ 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 -ENOEXEC;
+ }
+
+ return 0;
+}
+
+static int swap_load_devnode(Swap *s) {
+ _cleanup_(sd_device_unrefp) sd_device *d = NULL;
+ struct stat st;
+ const char *p;
+ int r;
+
+ assert(s);
+
+ if (stat(s->what, &st) < 0 || !S_ISBLK(st.st_mode))
+ return 0;
+
+ r = device_new_from_stat_rdev(&d, &st);
+ if (r < 0) {
+ log_unit_full(UNIT(s), r == -ENOENT ? LOG_DEBUG : LOG_WARNING, r,
+ "Failed to allocate device for swap %s: %m", s->what);
+ return 0;
+ }
+
+ if (sd_device_get_devname(d, &p) < 0)
+ return 0;
+
+ return swap_set_devnode(s, p);
+}
+
+static int swap_add_extras(Swap *s) {
+ int r;
+
+ assert(s);
+
+ 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(UNIT(s)->id, &s->what);
+ if (r < 0)
+ return r;
+ }
+
+ if (!s->what)
+ return -ENOMEM;
+ }
+
+ path_simplify(s->what, false);
+
+ if (!UNIT(s)->description) {
+ r = unit_set_description(UNIT(s), s->what);
+ if (r < 0)
+ return r;
+ }
+
+ r = unit_require_mounts_for(UNIT(s), s->what, UNIT_DEPENDENCY_IMPLICIT);
+ if (r < 0)
+ return r;
+
+ r = swap_add_device_dependencies(s);
+ if (r < 0)
+ return r;
+
+ r = swap_load_devnode(s);
+ if (r < 0)
+ return r;
+
+ r = unit_patch_contexts(UNIT(s));
+ if (r < 0)
+ return r;
+
+ r = unit_add_exec_dependencies(UNIT(s), &s->exec_context);
+ if (r < 0)
+ return r;
+
+ r = unit_set_default_slice(UNIT(s));
+ if (r < 0)
+ return r;
+
+ r = swap_add_default_dependencies(s);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
+static int swap_load(Unit *u) {
+ Swap *s = SWAP(u);
+ int r, q;
+
+ assert(s);
+ assert(u->load_state == UNIT_STUB);
+
+ /* Load a .swap file */
+ if (SWAP(u)->from_proc_swaps)
+ r = unit_load_fragment_and_dropin_optional(u);
+ else
+ r = unit_load_fragment_and_dropin(u);
+
+ /* Add in some extras, and do so either when we successfully loaded something or when /proc/swaps is already
+ * active. */
+ if (u->load_state == UNIT_LOADED || s->from_proc_swaps)
+ q = swap_add_extras(s);
+ else
+ q = 0;
+
+ if (r < 0)
+ return r;
+ if (q < 0)
+ return q;
+
+ 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))
+ return log_error_errno(SYNTHETIC_ERRNO(EEXIST),
+ "Swap %s appeared twice with different device paths %s and %s",
+ e, SWAP(u)->parameters_proc_swaps.what, what_proc_swaps);
+
+ if (!u) {
+ delete = true;
+
+ r = unit_new_for_name(m, sizeof(Swap), e, &u);
+ 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;
+ }
+ }
+
+ /* The unit is definitely around now, mark it as loaded if it was previously referenced but could not be
+ * loaded. After all we can load it now, from the data in /proc/swaps. */
+ if (IN_SET(u->load_state, UNIT_NOT_FOUND, UNIT_BAD_SETTING, UNIT_ERROR)) {
+ u->load_state = UNIT_LOADED;
+ u->load_error = 0;
+ }
+
+ 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)
+ unit_free(u);
+
+ return r;
+}
+
+static int swap_process_new(Manager *m, const char *device, int prio, bool set_flags) {
+ _cleanup_(sd_device_unrefp) sd_device *d = NULL;
+ const char *dn, *devlink;
+ struct stat st, st_link;
+ 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;
+
+ r = device_new_from_stat_rdev(&d, &st);
+ if (r < 0) {
+ log_full_errno(r == -ENOENT ? LOG_DEBUG : LOG_WARNING, r,
+ "Failed to allocate device for swap %s: %m", device);
+ return 0;
+ }
+
+ /* Add the main device node */
+ if (sd_device_get_devname(d, &dn) >= 0 && !streq(dn, device))
+ swap_setup_unit(m, dn, device, prio, set_flags);
+
+ /* Add additional units for all symlinks */
+ FOREACH_DEVICE_DEVLINK(d, devlink) {
+
+ /* Don't bother with the /dev/block links */
+ if (streq(devlink, device))
+ continue;
+
+ if (path_startswith(devlink, "/dev/block/"))
+ continue;
+
+ if (stat(devlink, &st_link) >= 0 &&
+ (!S_ISBLK(st_link.st_mode) ||
+ st_link.st_rdev != st.st_rdev))
+ continue;
+
+ swap_setup_unit(m, devlink, device, prio, set_flags);
+ }
+
+ return 0;
+}
+
+static void swap_set_state(Swap *s, SwapState state) {
+ SwapState old_state;
+ Swap *other;
+
+ assert(s);
+
+ if (s->state != state)
+ bus_unit_send_pending_change_signal(UNIT(s), false);
+
+ old_state = s->state;
+ s->state = state;
+
+ if (!SWAP_STATE_WITH_PROCESS(state)) {
+ 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], 0);
+
+ /* 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) &&
+ SWAP_STATE_WITH_PROCESS(new_state)) {
+
+ r = unit_watch_pid(UNIT(s), s->control_pid);
+ if (r < 0)
+ return r;
+
+ r = swap_arm_timer(s, usec_add(u->state_change_timestamp.monotonic, s->timeout_usec));
+ if (r < 0)
+ return r;
+ }
+
+ if (!IN_SET(new_state, SWAP_DEAD, SWAP_FAILED)) {
+ (void) unit_setup_dynamic_creds(u);
+ (void) unit_setup_exec_runtime(u);
+ }
+
+ swap_set_state(s, new_state);
+ return 0;
+}
+
+static void swap_dump(Unit *u, FILE *f, const char *prefix) {
+ char buf[FORMAT_TIMESPAN_MAX];
+ 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));
+
+ fprintf(f,
+ "%sTimeoutSec: %s\n",
+ prefix, format_timespan(buf, sizeof(buf), s->timeout_usec, USEC_PER_SEC));
+
+ 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);
+ cgroup_context_dump(&s->cgroup_context, f, prefix);
+}
+
+static int swap_spawn(Swap *s, ExecCommand *c, pid_t *_pid) {
+
+ _cleanup_(exec_params_clear) ExecParameters exec_params = {
+ .flags = EXEC_APPLY_SANDBOXING|EXEC_APPLY_CHROOT|EXEC_APPLY_TTY_STDIN,
+ .stdin_fd = -1,
+ .stdout_fd = -1,
+ .stderr_fd = -1,
+ .exec_fd = -1,
+ };
+ pid_t pid;
+ int r;
+
+ assert(s);
+ assert(c);
+ assert(_pid);
+
+ r = unit_prepare_exec(UNIT(s));
+ if (r < 0)
+ return r;
+
+ r = swap_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_usec));
+ if (r < 0)
+ goto fail;
+
+ r = unit_set_exec_params(UNIT(s), &exec_params);
+ if (r < 0)
+ goto fail;
+
+ r = exec_spawn(UNIT(s),
+ c,
+ &s->exec_context,
+ &exec_params,
+ s->exec_runtime,
+ &s->dynamic_creds,
+ &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 (s->result == SWAP_SUCCESS)
+ s->result = f;
+
+ unit_log_result(UNIT(s), s->result == SWAP_SUCCESS, swap_result_to_string(s->result));
+ swap_set_state(s, s->result != SWAP_SUCCESS ? SWAP_FAILED : SWAP_DEAD);
+
+ s->exec_runtime = exec_runtime_unref(s->exec_runtime, true);
+
+ exec_context_destroy_runtime_directory(&s->exec_context, UNIT(s)->manager->prefix[EXEC_DIRECTORY_RUNTIME]);
+
+ unit_unref_uid_gid(UNIT(s), true);
+
+ dynamic_creds_destroy(&s->dynamic_creds);
+}
+
+static void swap_enter_active(Swap *s, SwapResult f) {
+ assert(s);
+
+ if (s->result == SWAP_SUCCESS)
+ s->result = f;
+
+ swap_set_state(s, SWAP_ACTIVE);
+}
+
+static void swap_enter_dead_or_active(Swap *s, SwapResult f) {
+ assert(s);
+
+ if (s->from_proc_swaps)
+ swap_enter_active(s, f);
+ else
+ swap_enter_dead(s, f);
+}
+
+static void swap_enter_signal(Swap *s, SwapState state, SwapResult f) {
+ int r;
+ KillOperation kop;
+
+ assert(s);
+
+ if (s->result == SWAP_SUCCESS)
+ s->result = f;
+
+ if (state == SWAP_DEACTIVATING_SIGTERM)
+ kop = KILL_TERMINATE;
+ else
+ kop = KILL_KILL;
+
+ r = unit_kill_context(UNIT(s), &s->kill_context, kop, -1, s->control_pid, false);
+ if (r < 0)
+ goto fail;
+
+ if (r > 0) {
+ r = swap_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_usec));
+ if (r < 0)
+ goto fail;
+
+ swap_set_state(s, state);
+ } else if (state == SWAP_DEACTIVATING_SIGTERM && s->kill_context.send_sigkill)
+ swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, SWAP_SUCCESS);
+ else
+ swap_enter_dead_or_active(s, SWAP_SUCCESS);
+
+ return;
+
+fail:
+ log_unit_warning_errno(UNIT(s), r, "Failed to kill processes: %m");
+ swap_enter_dead_or_active(s, SWAP_FAILURE_RESOURCES);
+}
+
+static void swap_enter_activating(Swap *s) {
+ _cleanup_free_ char *opts = NULL;
+ int r;
+
+ assert(s);
+
+ unit_warn_leftover_processes(UNIT(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_or_active(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_dead_or_active(s, SWAP_FAILURE_RESOURCES);
+}
+
+static void swap_cycle_clear(Swap *s) {
+ assert(s);
+
+ s->result = SWAP_SUCCESS;
+ exec_command_reset_status_array(s->exec_command, _SWAP_EXEC_COMMAND_MAX);
+ UNIT(s)->reset_accounting = true;
+}
+
+static int swap_start(Unit *u) {
+ Swap *s = SWAP(u), *other;
+ int r;
+
+ assert(s);
+
+ /* We cannot fulfill this request right now, try again later please! */
+ if (IN_SET(s->state,
+ SWAP_DEACTIVATING,
+ SWAP_DEACTIVATING_SIGTERM,
+ SWAP_DEACTIVATING_SIGKILL))
+ return -EAGAIN;
+
+ /* Already on it! */
+ if (s->state == SWAP_ACTIVATING)
+ return 0;
+
+ assert(IN_SET(s->state, SWAP_DEAD, 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;
+
+ r = unit_start_limit_test(u);
+ if (r < 0) {
+ swap_enter_dead(s, SWAP_FAILURE_START_LIMIT_HIT);
+ return r;
+ }
+
+ r = unit_acquire_invocation_id(u);
+ if (r < 0)
+ return r;
+
+ swap_cycle_clear(s);
+ swap_enter_activating(s);
+ return 1;
+}
+
+static int swap_stop(Unit *u) {
+ Swap *s = SWAP(u);
+
+ assert(s);
+
+ switch (s->state) {
+
+ case SWAP_DEACTIVATING:
+ case SWAP_DEACTIVATING_SIGTERM:
+ case SWAP_DEACTIVATING_SIGKILL:
+ /* Already on it */
+ return 0;
+
+ case SWAP_ACTIVATING:
+ case SWAP_ACTIVATING_DONE:
+ /* There's a control process pending, directly enter kill mode */
+ swap_enter_signal(s, SWAP_DEACTIVATING_SIGTERM, SWAP_SUCCESS);
+ return 0;
+
+ case SWAP_ACTIVE:
+ if (detect_container() > 0)
+ return -EPERM;
+
+ swap_enter_deactivating(s);
+ return 1;
+
+ default:
+ assert_not_reached("Unexpected state.");
+ }
+}
+
+static int swap_serialize(Unit *u, FILE *f, FDSet *fds) {
+ Swap *s = SWAP(u);
+
+ assert(s);
+ assert(f);
+ assert(fds);
+
+ (void) serialize_item(f, "state", swap_state_to_string(s->state));
+ (void) serialize_item(f, "result", swap_result_to_string(s->result));
+
+ if (s->control_pid > 0)
+ (void) serialize_item_format(f, "control-pid", PID_FMT, s->control_pid);
+
+ if (s->control_command_id >= 0)
+ (void) serialize_item(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_may_gc(Unit *u) {
+ Swap *s = SWAP(u);
+
+ assert(s);
+
+ if (s->from_proc_swaps)
+ return false;
+
+ return true;
+}
+
+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, EXIT_CLEAN_COMMAND, 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 (s->result == 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;
+ }
+
+ unit_log_process_exit(
+ u, f == SWAP_SUCCESS ? LOG_DEBUG : LOG_NOTICE,
+ "Swap process",
+ swap_exec_command_to_string(s->control_command_id),
+ code, status);
+
+ switch (s->state) {
+
+ case SWAP_ACTIVATING:
+ case SWAP_ACTIVATING_DONE:
+
+ if (f == SWAP_SUCCESS || s->from_proc_swaps)
+ 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_or_active(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_DEACTIVATING_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_DEACTIVATING_SIGTERM:
+ if (s->kill_context.send_sigkill) {
+ log_unit_warning(UNIT(s), "Swap process timed out. Killing.");
+ swap_enter_signal(s, SWAP_DEACTIVATING_SIGKILL, SWAP_FAILURE_TIMEOUT);
+ } else {
+ log_unit_warning(UNIT(s), "Swap process timed out. Skipping SIGKILL. Ignoring.");
+ swap_enter_dead_or_active(s, SWAP_FAILURE_TIMEOUT);
+ }
+ break;
+
+ case SWAP_DEACTIVATING_SIGKILL:
+ log_unit_warning(UNIT(s), "Swap process still around after SIGKILL. Ignoring.");
+ swap_enter_dead_or_active(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;
+
+ 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, DEVICE_FOUND_SWAP, DEVICE_FOUND_SWAP);
+
+ (void) swap_process_new(m, d, prio, set_flags);
+ }
+
+ return 0;
+}
+
+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) {
+
+ swap_unset_proc_swaps(swap);
+
+ switch (swap->state) {
+
+ case SWAP_ACTIVE:
+ /* This has just been deactivated */
+ 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, 0, DEVICE_FOUND_SWAP);
+
+ } else if (swap->just_activated) {
+
+ /* New swap entry */
+
+ switch (swap->state) {
+
+ case SWAP_DEAD:
+ case SWAP_FAILED:
+ (void) unit_acquire_invocation_id(u);
+ swap_cycle_clear(swap);
+ 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;
+ _cleanup_set_free_ Set *set = NULL;
+ 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)
+ return r;
+ }
+
+ *_set = TAKE_PTR(set);
+ return 1;
+}
+
+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_errno(errno, "Not swap enabled, skipping enumeration.");
+ else
+ log_warning_errno(errno, "Failed to open /proc/swaps, ignoring: %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, SD_EVENT_PRIORITY_NORMAL-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, sd_device *dev) {
+ _cleanup_free_ char *e = NULL;
+ const char *dn, *devlink;
+ Unit *u;
+ int r = 0;
+
+ assert(m);
+ assert(dev);
+
+ r = sd_device_get_devname(dev, &dn);
+ if (r < 0)
+ return 0;
+
+ r = unit_name_from_path(dn, ".swap", &e);
+ if (r < 0)
+ return r;
+
+ u = manager_get_unit(m, e);
+ if (u)
+ r = swap_set_devnode(SWAP(u), dn);
+
+ FOREACH_DEVICE_DEVLINK(dev, devlink) {
+ _cleanup_free_ char *n = NULL;
+ int q;
+
+ q = unit_name_from_path(devlink, ".swap", &n);
+ if (q < 0)
+ return q;
+
+ u = manager_get_unit(m, n);
+ if (u) {
+ q = swap_set_devnode(SWAP(u), dn);
+ if (q < 0)
+ r = q;
+ }
+ }
+
+ return r;
+}
+
+int swap_process_device_remove(Manager *m, sd_device *dev) {
+ const char *dn;
+ int r = 0;
+ Swap *s;
+
+ r = sd_device_get_devname(dev, &dn);
+ if (r < 0)
+ 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, usec_t *timeout) {
+ Swap *s = SWAP(u);
+ usec_t t;
+ int r;
+
+ if (!s->timer_event_source)
+ return 0;
+
+ r = sd_event_source_get_time(s->timer_event_source, &t);
+ if (r < 0)
+ return r;
+ if (t == USEC_INFINITY)
+ return 0;
+
+ *timeout = t;
+ 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 int swap_control_pid(Unit *u) {
+ Swap *s = SWAP(u);
+
+ assert(s);
+
+ return s->control_pid;
+}
+
+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",
+ [SWAP_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
+};
+
+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),
+ .dynamic_creds_offset = offsetof(Swap, dynamic_creds),
+
+ .sections =
+ "Unit\0"
+ "Swap\0"
+ "Install\0",
+ .private_section = "Swap",
+
+ .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,
+
+ .may_gc = swap_may_gc,
+
+ .sigchld_event = swap_sigchld_event,
+
+ .reset_failed = swap_reset_failed,
+
+ .control_pid = swap_control_pid,
+
+ .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.",
+ },
+ },
+};