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Systemd/src/manager.c

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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 General Public License as published by
the Free Software Foundation; either version 2 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <assert.h>
#include <errno.h>
#include <string.h>
#include <sys/epoll.h>
#include <signal.h>
#include <sys/signalfd.h>
#include <sys/wait.h>
#include <unistd.h>
#include <sys/poll.h>
#include <sys/reboot.h>
#include <sys/ioctl.h>
#include <linux/kd.h>
#include <termios.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#ifdef HAVE_AUDIT
#include <libaudit.h>
#endif
#include "manager.h"
#include "hashmap.h"
#include "macro.h"
#include "strv.h"
#include "log.h"
#include "util.h"
#include "ratelimit.h"
#include "cgroup.h"
#include "mount-setup.h"
#include "unit-name.h"
#include "dbus-unit.h"
#include "dbus-job.h"
#include "missing.h"
#include "path-lookup.h"
#include "special.h"
#include "bus-errors.h"
#include "exit-status.h"
/* As soon as 16 units are in our GC queue, make sure to run a gc sweep */
#define GC_QUEUE_ENTRIES_MAX 16
/* As soon as 5s passed since a unit was added to our GC queue, make sure to run a gc sweep */
#define GC_QUEUE_USEC_MAX (10*USEC_PER_SEC)
/* Where clients shall send notification messages to */
#define NOTIFY_SOCKET "/org/freedesktop/systemd1/notify"
static int manager_setup_notify(Manager *m) {
union {
struct sockaddr sa;
struct sockaddr_un un;
} sa;
struct epoll_event ev;
int one = 1;
assert(m);
m->notify_watch.type = WATCH_NOTIFY;
if ((m->notify_watch.fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0)) < 0) {
log_error("Failed to allocate notification socket: %m");
return -errno;
}
zero(sa);
sa.sa.sa_family = AF_UNIX;
if (getpid() != 1)
snprintf(sa.un.sun_path+1, sizeof(sa.un.sun_path)-1, NOTIFY_SOCKET "/%llu", random_ull());
else
strncpy(sa.un.sun_path+1, NOTIFY_SOCKET, sizeof(sa.un.sun_path)-1);
if (bind(m->notify_watch.fd, &sa.sa, sizeof(sa_family_t) + 1 + strlen(sa.un.sun_path+1)) < 0) {
log_error("bind() failed: %m");
return -errno;
}
if (setsockopt(m->notify_watch.fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0) {
log_error("SO_PASSCRED failed: %m");
return -errno;
}
zero(ev);
ev.events = EPOLLIN;
ev.data.ptr = &m->notify_watch;
if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->notify_watch.fd, &ev) < 0)
return -errno;
if (!(m->notify_socket = strdup(sa.un.sun_path+1)))
return -ENOMEM;
return 0;
}
static int enable_special_signals(Manager *m) {
char fd;
assert(m);
/* Enable that we get SIGINT on control-alt-del */
if (reboot(RB_DISABLE_CAD) < 0)
log_warning("Failed to enable ctrl-alt-del handling: %m");
if ((fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY)) < 0)
log_warning("Failed to open /dev/tty0: %m");
else {
/* Enable that we get SIGWINCH on kbrequest */
if (ioctl(fd, KDSIGACCEPT, SIGWINCH) < 0)
log_warning("Failed to enable kbrequest handling: %s", strerror(errno));
close_nointr_nofail(fd);
}
return 0;
}
static int manager_setup_signals(Manager *m) {
sigset_t mask;
struct epoll_event ev;
struct sigaction sa;
assert(m);
/* We are not interested in SIGSTOP and friends. */
zero(sa);
sa.sa_handler = SIG_DFL;
sa.sa_flags = SA_NOCLDSTOP|SA_RESTART;
assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
assert_se(sigemptyset(&mask) == 0);
sigset_add_many(&mask,
SIGCHLD, /* Child died */
SIGTERM, /* Reexecute daemon */
SIGHUP, /* Reload configuration */
SIGUSR1, /* systemd/upstart: reconnect to D-Bus */
SIGUSR2, /* systemd: dump status */
SIGINT, /* Kernel sends us this on control-alt-del */
SIGWINCH, /* Kernel sends us this on kbrequest (alt-arrowup) */
SIGPWR, /* Some kernel drivers and upsd send us this on power failure */
SIGRTMIN+0, /* systemd: start default.target */
SIGRTMIN+1, /* systemd: start rescue.target */
SIGRTMIN+2, /* systemd: isolate emergency.target */
SIGRTMIN+3, /* systemd: start halt.target */
SIGRTMIN+4, /* systemd: start poweroff.target */
SIGRTMIN+5, /* systemd: start reboot.target */
-1);
assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
m->signal_watch.type = WATCH_SIGNAL;
if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
return -errno;
zero(ev);
ev.events = EPOLLIN;
ev.data.ptr = &m->signal_watch;
if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
return -errno;
if (m->running_as == MANAGER_SYSTEM)
return enable_special_signals(m);
return 0;
}
int manager_new(ManagerRunningAs running_as, Manager **_m) {
Manager *m;
int r = -ENOMEM;
assert(_m);
assert(running_as >= 0);
assert(running_as < _MANAGER_RUNNING_AS_MAX);
if (!(m = new0(Manager, 1)))
return -ENOMEM;
dual_timestamp_get(&m->startup_timestamp);
m->running_as = running_as;
m->name_data_slot = m->subscribed_data_slot = -1;
m->exit_code = _MANAGER_EXIT_CODE_INVALID;
m->pin_cgroupfs_fd = -1;
#ifdef HAVE_AUDIT
m->audit_fd = -1;
#endif
m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = m->dev_autofs_fd = -1;
m->current_job_id = 1; /* start as id #1, so that we can leave #0 around as "null-like" value */
if (!(m->environment = strv_copy(environ)))
goto fail;
if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
goto fail;
if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
goto fail;
if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
goto fail;
if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
goto fail;
if (!(m->cgroup_bondings = hashmap_new(string_hash_func, string_compare_func)))
goto fail;
if (!(m->watch_bus = hashmap_new(string_hash_func, string_compare_func)))
goto fail;
if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
goto fail;
if ((r = lookup_paths_init(&m->lookup_paths, m->running_as)) < 0)
goto fail;
if ((r = manager_setup_signals(m)) < 0)
goto fail;
if ((r = manager_setup_cgroup(m)) < 0)
goto fail;
if ((r = manager_setup_notify(m)) < 0)
goto fail;
/* Try to connect to the busses, if possible. */
if ((r = bus_init(m)) < 0)
goto fail;
#ifdef HAVE_AUDIT
if ((m->audit_fd = audit_open()) < 0)
log_error("Failed to connect to audit log: %m");
#endif
*_m = m;
return 0;
fail:
manager_free(m);
return r;
}
static unsigned manager_dispatch_cleanup_queue(Manager *m) {
Meta *meta;
unsigned n = 0;
assert(m);
while ((meta = m->cleanup_queue)) {
assert(meta->in_cleanup_queue);
unit_free((Unit*) meta);
n++;
}
return n;
}
enum {
GC_OFFSET_IN_PATH, /* This one is on the path we were travelling */
GC_OFFSET_UNSURE, /* No clue */
GC_OFFSET_GOOD, /* We still need this unit */
GC_OFFSET_BAD, /* We don't need this unit anymore */
_GC_OFFSET_MAX
};
static void unit_gc_sweep(Unit *u, unsigned gc_marker) {
Iterator i;
Unit *other;
bool is_bad;
assert(u);
if (u->meta.gc_marker == gc_marker + GC_OFFSET_GOOD ||
u->meta.gc_marker == gc_marker + GC_OFFSET_BAD ||
u->meta.gc_marker == gc_marker + GC_OFFSET_IN_PATH)
return;
if (u->meta.in_cleanup_queue)
goto bad;
if (unit_check_gc(u))
goto good;
u->meta.gc_marker = gc_marker + GC_OFFSET_IN_PATH;
is_bad = true;
SET_FOREACH(other, u->meta.dependencies[UNIT_REFERENCED_BY], i) {
unit_gc_sweep(other, gc_marker);
if (other->meta.gc_marker == gc_marker + GC_OFFSET_GOOD)
goto good;
if (other->meta.gc_marker != gc_marker + GC_OFFSET_BAD)
is_bad = false;
}
if (is_bad)
goto bad;
/* We were unable to find anything out about this entry, so
* let's investigate it later */
u->meta.gc_marker = gc_marker + GC_OFFSET_UNSURE;
unit_add_to_gc_queue(u);
return;
bad:
/* We definitely know that this one is not useful anymore, so
* let's mark it for deletion */
u->meta.gc_marker = gc_marker + GC_OFFSET_BAD;
unit_add_to_cleanup_queue(u);
return;
good:
u->meta.gc_marker = gc_marker + GC_OFFSET_GOOD;
}
static unsigned manager_dispatch_gc_queue(Manager *m) {
Meta *meta;
unsigned n = 0;
unsigned gc_marker;
assert(m);
if ((m->n_in_gc_queue < GC_QUEUE_ENTRIES_MAX) &&
(m->gc_queue_timestamp <= 0 ||
(m->gc_queue_timestamp + GC_QUEUE_USEC_MAX) > now(CLOCK_MONOTONIC)))
return 0;
log_debug("Running GC...");
m->gc_marker += _GC_OFFSET_MAX;
if (m->gc_marker + _GC_OFFSET_MAX <= _GC_OFFSET_MAX)
m->gc_marker = 1;
gc_marker = m->gc_marker;
while ((meta = m->gc_queue)) {
assert(meta->in_gc_queue);
unit_gc_sweep((Unit*) meta, gc_marker);
LIST_REMOVE(Meta, gc_queue, m->gc_queue, meta);
meta->in_gc_queue = false;
n++;
if (meta->gc_marker == gc_marker + GC_OFFSET_BAD ||
meta->gc_marker == gc_marker + GC_OFFSET_UNSURE) {
log_debug("Collecting %s", meta->id);
meta->gc_marker = gc_marker + GC_OFFSET_BAD;
unit_add_to_cleanup_queue((Unit*) meta);
}
}
m->n_in_gc_queue = 0;
m->gc_queue_timestamp = 0;
return n;
}
static void manager_clear_jobs_and_units(Manager *m) {
Job *j;
Unit *u;
assert(m);
while ((j = hashmap_first(m->transaction_jobs)))
job_free(j);
while ((u = hashmap_first(m->units)))
unit_free(u);
manager_dispatch_cleanup_queue(m);
assert(!m->load_queue);
assert(!m->run_queue);
assert(!m->dbus_unit_queue);
assert(!m->dbus_job_queue);
assert(!m->cleanup_queue);
assert(!m->gc_queue);
assert(hashmap_isempty(m->transaction_jobs));
assert(hashmap_isempty(m->jobs));
assert(hashmap_isempty(m->units));
}
void manager_free(Manager *m) {
UnitType c;
assert(m);
manager_clear_jobs_and_units(m);
for (c = 0; c < _UNIT_TYPE_MAX; c++)
if (unit_vtable[c]->shutdown)
unit_vtable[c]->shutdown(m);
/* If we reexecute ourselves, we keep the root cgroup
* around */
manager_shutdown_cgroup(m, m->exit_code != MANAGER_REEXECUTE);
bus_done(m);
hashmap_free(m->units);
hashmap_free(m->jobs);
hashmap_free(m->transaction_jobs);
hashmap_free(m->watch_pids);
hashmap_free(m->watch_bus);
if (m->epoll_fd >= 0)
close_nointr_nofail(m->epoll_fd);
if (m->signal_watch.fd >= 0)
close_nointr_nofail(m->signal_watch.fd);
if (m->notify_watch.fd >= 0)
close_nointr_nofail(m->notify_watch.fd);
#ifdef HAVE_AUDIT
if (m->audit_fd >= 0)
audit_close(m->audit_fd);
#endif
free(m->notify_socket);
lookup_paths_free(&m->lookup_paths);
strv_free(m->environment);
hashmap_free(m->cgroup_bondings);
set_free_free(m->unit_path_cache);
free(m);
}
int manager_enumerate(Manager *m) {
int r = 0, q;
UnitType c;
assert(m);
/* Let's ask every type to load all units from disk/kernel
* that it might know */
for (c = 0; c < _UNIT_TYPE_MAX; c++)
if (unit_vtable[c]->enumerate)
if ((q = unit_vtable[c]->enumerate(m)) < 0)
r = q;
manager_dispatch_load_queue(m);
return r;
}
int manager_coldplug(Manager *m) {
int r = 0, q;
Iterator i;
Unit *u;
char *k;
assert(m);
/* Then, let's set up their initial state. */
HASHMAP_FOREACH_KEY(u, k, m->units, i) {
/* ignore aliases */
if (u->meta.id != k)
continue;
if ((q = unit_coldplug(u)) < 0)
r = q;
}
return r;
}
static void manager_build_unit_path_cache(Manager *m) {
char **i;
DIR *d = NULL;
int r;
assert(m);
set_free_free(m->unit_path_cache);
if (!(m->unit_path_cache = set_new(string_hash_func, string_compare_func))) {
log_error("Failed to allocate unit path cache.");
return;
}
/* This simply builds a list of files we know exist, so that
* we don't always have to go to disk */
STRV_FOREACH(i, m->lookup_paths.unit_path) {
struct dirent *de;
if (!(d = opendir(*i))) {
log_error("Failed to open directory: %m");
continue;
}
while ((de = readdir(d))) {
char *p;
if (ignore_file(de->d_name))
continue;
if (asprintf(&p, "%s/%s", streq(*i, "/") ? "" : *i, de->d_name) < 0) {
r = -ENOMEM;
goto fail;
}
if ((r = set_put(m->unit_path_cache, p)) < 0) {
free(p);
goto fail;
}
}
closedir(d);
d = NULL;
}
return;
fail:
log_error("Failed to build unit path cache: %s", strerror(-r));
set_free_free(m->unit_path_cache);
m->unit_path_cache = NULL;
if (d)
closedir(d);
}
int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
int r, q;
assert(m);
manager_build_unit_path_cache(m);
/* If we will deserialize make sure that during enumeration
* this is already known, so we increase the counter here
* already */
if (serialization)
m->n_deserializing ++;
/* First, enumerate what we can from all config files */
r = manager_enumerate(m);
/* Second, deserialize if there is something to deserialize */
if (serialization)
if ((q = manager_deserialize(m, serialization, fds)) < 0)
r = q;
/* Third, fire things up! */
if ((q = manager_coldplug(m)) < 0)
r = q;
if (serialization) {
assert(m->n_deserializing > 0);
m->n_deserializing --;
}
return r;
}
static void transaction_delete_job(Manager *m, Job *j, bool delete_dependencies) {
assert(m);
assert(j);
/* Deletes one job from the transaction */
manager_transaction_unlink_job(m, j, delete_dependencies);
if (!j->installed)
job_free(j);
}
static void transaction_delete_unit(Manager *m, Unit *u) {
Job *j;
/* Deletes all jobs associated with a certain unit from the
* transaction */
while ((j = hashmap_get(m->transaction_jobs, u)))
transaction_delete_job(m, j, true);
}
static void transaction_clean_dependencies(Manager *m) {
Iterator i;
Job *j;
assert(m);
/* Drops all dependencies of all installed jobs */
HASHMAP_FOREACH(j, m->jobs, i) {
while (j->subject_list)
job_dependency_free(j->subject_list);
while (j->object_list)
job_dependency_free(j->object_list);
}
assert(!m->transaction_anchor);
}
static void transaction_abort(Manager *m) {
Job *j;
assert(m);
while ((j = hashmap_first(m->transaction_jobs)))
if (j->installed)
transaction_delete_job(m, j, true);
else
job_free(j);
assert(hashmap_isempty(m->transaction_jobs));
transaction_clean_dependencies(m);
}
static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
JobDependency *l;
assert(m);
/* A recursive sweep through the graph that marks all units
* that matter to the anchor job, i.e. are directly or
* indirectly a dependency of the anchor job via paths that
* are fully marked as mattering. */
if (j)
l = j->subject_list;
else
l = m->transaction_anchor;
LIST_FOREACH(subject, l, l) {
/* This link does not matter */
if (!l->matters)
continue;
/* This unit has already been marked */
if (l->object->generation == generation)
continue;
l->object->matters_to_anchor = true;
l->object->generation = generation;
transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
}
}
static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
JobDependency *l, *last;
assert(j);
assert(other);
assert(j->unit == other->unit);
assert(!j->installed);
/* Merges 'other' into 'j' and then deletes j. */
j->type = t;
j->state = JOB_WAITING;
j->override = j->override || other->override;
j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
/* Patch us in as new owner of the JobDependency objects */
last = NULL;
LIST_FOREACH(subject, l, other->subject_list) {
assert(l->subject == other);
l->subject = j;
last = l;
}
/* Merge both lists */
if (last) {
last->subject_next = j->subject_list;
if (j->subject_list)
j->subject_list->subject_prev = last;
j->subject_list = other->subject_list;
}
/* Patch us in as new owner of the JobDependency objects */
last = NULL;
LIST_FOREACH(object, l, other->object_list) {
assert(l->object == other);
l->object = j;
last = l;
}
/* Merge both lists */
if (last) {
last->object_next = j->object_list;
if (j->object_list)
j->object_list->object_prev = last;
j->object_list = other->object_list;
}
/* Kill the other job */
other->subject_list = NULL;
other->object_list = NULL;
transaction_delete_job(m, other, true);
}
static bool job_is_conflicted_by(Job *j) {
JobDependency *l;
assert(j);
/* Returns true if this job is pulled in by a least one
* ConflictedBy dependency. */
LIST_FOREACH(object, l, j->object_list)
if (l->conflicts)
return true;
return false;
}
static int delete_one_unmergeable_job(Manager *m, Job *j) {
Job *k;
assert(j);
/* Tries to delete one item in the linked list
* j->transaction_next->transaction_next->... that conflicts
* whith another one, in an attempt to make an inconsistent
* transaction work. */
/* We rely here on the fact that if a merged with b does not
* merge with c, either a or b merge with c neither */
LIST_FOREACH(transaction, j, j)
LIST_FOREACH(transaction, k, j->transaction_next) {
Job *d;
/* Is this one mergeable? Then skip it */
if (job_type_is_mergeable(j->type, k->type))
continue;
/* Ok, we found two that conflict, let's see if we can
* drop one of them */
if (!j->matters_to_anchor && !k->matters_to_anchor) {
/* Both jobs don't matter, so let's
* find the one that is smarter to
* remove. Let's think positive and
* rather remove stops then starts --
* except if something is being
* stopped because it is conflicted by
* another unit in which case we
* rather remove the start. */
log_debug("Looking at job %s/%s conflicted_by=%s", j->unit->meta.id, job_type_to_string(j->type), yes_no(j->type == JOB_STOP && job_is_conflicted_by(j)));
log_debug("Looking at job %s/%s conflicted_by=%s", k->unit->meta.id, job_type_to_string(k->type), yes_no(k->type == JOB_STOP && job_is_conflicted_by(k)));
if (j->type == JOB_STOP) {
if (job_is_conflicted_by(j))
d = k;
else
d = j;
} else if (k->type == JOB_STOP) {
if (job_is_conflicted_by(k))
d = j;
else
d = k;
} else
d = j;
} else if (!j->matters_to_anchor)
d = j;
else if (!k->matters_to_anchor)
d = k;
else
return -ENOEXEC;
/* Ok, we can drop one, so let's do so. */
log_debug("Fixing conflicting jobs by deleting job %s/%s", d->unit->meta.id, job_type_to_string(d->type));
transaction_delete_job(m, d, true);
return 0;
}
return -EINVAL;
}
static int transaction_merge_jobs(Manager *m, DBusError *e) {
Job *j;
Iterator i;
int r;
assert(m);
/* First step, check whether any of the jobs for one specific
* task conflict. If so, try to drop one of them. */
HASHMAP_FOREACH(j, m->transaction_jobs, i) {
JobType t;
Job *k;
t = j->type;
LIST_FOREACH(transaction, k, j->transaction_next) {
if (job_type_merge(&t, k->type) >= 0)
continue;
/* OK, we could not merge all jobs for this
* action. Let's see if we can get rid of one
* of them */
if ((r = delete_one_unmergeable_job(m, j)) >= 0)
/* Ok, we managed to drop one, now
* let's ask our callers to call us
* again after garbage collecting */
return -EAGAIN;
/* We couldn't merge anything. Failure */
dbus_set_error(e, BUS_ERROR_TRANSACTION_JOBS_CONFLICTING, "Transaction contains conflicting jobs '%s' and '%s' for %s. Probably contradicting requirement dependencies configured.",
job_type_to_string(t), job_type_to_string(k->type), k->unit->meta.id);
return r;
}
}
/* Second step, merge the jobs. */
HASHMAP_FOREACH(j, m->transaction_jobs, i) {
JobType t = j->type;
Job *k;
/* Merge all transactions */
LIST_FOREACH(transaction, k, j->transaction_next)
assert_se(job_type_merge(&t, k->type) == 0);
/* If an active job is mergeable, merge it too */
if (j->unit->meta.job)
job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
while ((k = j->transaction_next)) {
if (j->installed) {
transaction_merge_and_delete_job(m, k, j, t);
j = k;
} else
transaction_merge_and_delete_job(m, j, k, t);
}
assert(!j->transaction_next);
assert(!j->transaction_prev);
}
return 0;
}
static void transaction_drop_redundant(Manager *m) {
bool again;
assert(m);
/* Goes through the transaction and removes all jobs that are
* a noop */
do {
Job *j;
Iterator i;
again = false;
HASHMAP_FOREACH(j, m->transaction_jobs, i) {
bool changes_something = false;
Job *k;
LIST_FOREACH(transaction, k, j) {
if (!job_is_anchor(k) &&
job_type_is_redundant(k->type, unit_active_state(k->unit)))
continue;
changes_something = true;
break;
}
if (changes_something)
continue;
log_debug("Found redundant job %s/%s, dropping.", j->unit->meta.id, job_type_to_string(j->type));
transaction_delete_job(m, j, false);
again = true;
break;
}
} while (again);
}
static bool unit_matters_to_anchor(Unit *u, Job *j) {
assert(u);
assert(!j->transaction_prev);
/* Checks whether at least one of the jobs for this unit
* matters to the anchor. */
LIST_FOREACH(transaction, j, j)
if (j->matters_to_anchor)
return true;
return false;
}
static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation, DBusError *e) {
Iterator i;
Unit *u;
int r;
assert(m);
assert(j);
assert(!j->transaction_prev);
/* Does a recursive sweep through the ordering graph, looking
* for a cycle. If we find cycle we try to break it. */
/* Have we seen this before? */
if (j->generation == generation) {
Job *k, *delete;
/* If the marker is NULL we have been here already and
* decided the job was loop-free from here. Hence
* shortcut things and return right-away. */
if (!j->marker)
return 0;
/* So, the marker is not NULL and we already have been
* here. We have a cycle. Let's try to break it. We go
* backwards in our path and try to find a suitable
* job to remove. We use the marker to find our way
* back, since smart how we are we stored our way back
* in there. */
log_warning("Found ordering cycle on %s/%s", j->unit->meta.id, job_type_to_string(j->type));
delete = NULL;
for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) {
log_info("Walked on cycle path to %s/%s", k->unit->meta.id, job_type_to_string(k->type));
if (!delete &&
!k->installed &&
!unit_matters_to_anchor(k->unit, k)) {
/* Ok, we can drop this one, so let's
* do so. */
delete = k;
}
/* Check if this in fact was the beginning of
* the cycle */
if (k == j)
break;
}
if (delete) {
log_warning("Breaking ordering cycle by deleting job %s/%s", k->unit->meta.id, job_type_to_string(k->type));
transaction_delete_unit(m, delete->unit);
return -EAGAIN;
}
log_error("Unable to break cycle");
dbus_set_error(e, BUS_ERROR_TRANSACTION_ORDER_IS_CYCLIC, "Transaction order is cyclic. See logs for details.");
return -ENOEXEC;
}
/* Make the marker point to where we come from, so that we can
* find our way backwards if we want to break a cycle. We use
* a special marker for the beginning: we point to
* ourselves. */
j->marker = from ? from : j;
j->generation = generation;
/* We assume that the the dependencies are bidirectional, and
* hence can ignore UNIT_AFTER */
SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
Job *o;
/* Is there a job for this unit? */
if (!(o = hashmap_get(m->transaction_jobs, u)))
/* Ok, there is no job for this in the
* transaction, but maybe there is already one
* running? */
if (!(o = u->meta.job))
continue;
if ((r = transaction_verify_order_one(m, o, j, generation, e)) < 0)
return r;
}
/* Ok, let's backtrack, and remember that this entry is not on
* our path anymore. */
j->marker = NULL;
return 0;
}
static int transaction_verify_order(Manager *m, unsigned *generation, DBusError *e) {
Job *j;
int r;
Iterator i;
unsigned g;
assert(m);
assert(generation);
/* Check if the ordering graph is cyclic. If it is, try to fix
* that up by dropping one of the jobs. */
g = (*generation)++;
HASHMAP_FOREACH(j, m->transaction_jobs, i)
if ((r = transaction_verify_order_one(m, j, NULL, g, e)) < 0)
return r;
return 0;
}
static void transaction_collect_garbage(Manager *m) {
bool again;
assert(m);
/* Drop jobs that are not required by any other job */
do {
Iterator i;
Job *j;
again = false;
HASHMAP_FOREACH(j, m->transaction_jobs, i) {
if (j->object_list)
continue;
log_debug("Garbage collecting job %s/%s", j->unit->meta.id, job_type_to_string(j->type));
transaction_delete_job(m, j, true);
again = true;
break;
}
} while (again);
}
static int transaction_is_destructive(Manager *m, DBusError *e) {
Iterator i;
Job *j;
assert(m);
/* Checks whether applying this transaction means that
* existing jobs would be replaced */
HASHMAP_FOREACH(j, m->transaction_jobs, i) {
/* Assume merged */
assert(!j->transaction_prev);
assert(!j->transaction_next);
if (j->unit->meta.job &&
j->unit->meta.job != j &&
!job_type_is_superset(j->type, j->unit->meta.job->type)) {
dbus_set_error(e, BUS_ERROR_TRANSACTION_IS_DESTRUCTIVE, "Transaction is destructive.");
return -EEXIST;
}
}
return 0;
}
static void transaction_minimize_impact(Manager *m) {
bool again;
assert(m);
/* Drops all unnecessary jobs that reverse already active jobs
* or that stop a running service. */
do {
Job *j;
Iterator i;
again = false;
HASHMAP_FOREACH(j, m->transaction_jobs, i) {
LIST_FOREACH(transaction, j, j) {
bool stops_running_service, changes_existing_job;
/* If it matters, we shouldn't drop it */
if (j->matters_to_anchor)
continue;
/* Would this stop a running service?
* Would this change an existing job?
* If so, let's drop this entry */
stops_running_service =
j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
changes_existing_job =
j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->type);
if (!stops_running_service && !changes_existing_job)
continue;
if (stops_running_service)
log_info("%s/%s would stop a running service.", j->unit->meta.id, job_type_to_string(j->type));
if (changes_existing_job)
log_info("%s/%s would change existing job.", j->unit->meta.id, job_type_to_string(j->type));
/* Ok, let's get rid of this */
log_info("Deleting %s/%s to minimize impact.", j->unit->meta.id, job_type_to_string(j->type));
transaction_delete_job(m, j, true);
again = true;
break;
}
if (again)
break;
}
} while (again);
}
static int transaction_apply(Manager *m) {
Iterator i;
Job *j;
int r;
/* Moves the transaction jobs to the set of active jobs */
HASHMAP_FOREACH(j, m->transaction_jobs, i) {
/* Assume merged */
assert(!j->transaction_prev);
assert(!j->transaction_next);
if (j->installed)
continue;
if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
goto rollback;
}
while ((j = hashmap_steal_first(m->transaction_jobs))) {
if (j->installed)
continue;
if (j->unit->meta.job)
job_free(j->unit->meta.job);
j->unit->meta.job = j;
j->installed = true;
/* We're fully installed. Now let's free data we don't
* need anymore. */
assert(!j->transaction_next);
assert(!j->transaction_prev);
job_add_to_run_queue(j);
job_add_to_dbus_queue(j);
job_start_timer(j);
}
/* As last step, kill all remaining job dependencies. */
transaction_clean_dependencies(m);
return 0;
rollback:
HASHMAP_FOREACH(j, m->transaction_jobs, i) {
if (j->installed)
continue;
hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
}
return r;
}
static int transaction_activate(Manager *m, JobMode mode, DBusError *e) {
int r;
unsigned generation = 1;
assert(m);
/* This applies the changes recorded in transaction_jobs to
* the actual list of jobs, if possible. */
/* First step: figure out which jobs matter */
transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
/* Second step: Try not to stop any running services if
* we don't have to. Don't try to reverse running
* jobs if we don't have to. */
transaction_minimize_impact(m);
/* Third step: Drop redundant jobs */
transaction_drop_redundant(m);
for (;;) {
/* Fourth step: Let's remove unneeded jobs that might
* be lurking. */
transaction_collect_garbage(m);
/* Fifth step: verify order makes sense and correct
* cycles if necessary and possible */
if ((r = transaction_verify_order(m, &generation, e)) >= 0)
break;
if (r != -EAGAIN) {
log_warning("Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error(e, r));
goto rollback;
}
/* Let's see if the resulting transaction ordering
* graph is still cyclic... */
}
for (;;) {
/* Sixth step: let's drop unmergeable entries if
* necessary and possible, merge entries we can
* merge */
if ((r = transaction_merge_jobs(m, e)) >= 0)
break;
if (r != -EAGAIN) {
log_warning("Requested transaction contains unmergable jobs: %s", bus_error(e, r));
goto rollback;
}
/* Seventh step: an entry got dropped, let's garbage
* collect its dependencies. */
transaction_collect_garbage(m);
/* Let's see if the resulting transaction still has
* unmergeable entries ... */
}
/* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
transaction_drop_redundant(m);
/* Ninth step: check whether we can actually apply this */
if (mode == JOB_FAIL)
if ((r = transaction_is_destructive(m, e)) < 0) {
log_notice("Requested transaction contradicts existing jobs: %s", bus_error(e, r));
goto rollback;
}
/* Tenth step: apply changes */
if ((r = transaction_apply(m)) < 0) {
log_warning("Failed to apply transaction: %s", strerror(-r));
goto rollback;
}
assert(hashmap_isempty(m->transaction_jobs));
assert(!m->transaction_anchor);
return 0;
rollback:
transaction_abort(m);
return r;
}
static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool override, bool *is_new) {
Job *j, *f;
assert(m);
assert(unit);
/* Looks for an axisting prospective job and returns that. If
* it doesn't exist it is created and added to the prospective
* jobs list. */
f = hashmap_get(m->transaction_jobs, unit);
LIST_FOREACH(transaction, j, f) {
assert(j->unit == unit);
if (j->type == type) {
if (is_new)
*is_new = false;
return j;
}
}
if (unit->meta.job && unit->meta.job->type == type)
j = unit->meta.job;
else if (!(j = job_new(m, type, unit)))
return NULL;
j->generation = 0;
j->marker = NULL;
j->matters_to_anchor = false;
j->override = override;
LIST_PREPEND(Job, transaction, f, j);
if (hashmap_replace(m->transaction_jobs, unit, f) < 0) {
job_free(j);
return NULL;
}
if (is_new)
*is_new = true;
log_debug("Added job %s/%s to transaction.", unit->meta.id, job_type_to_string(type));
return j;
}
void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
assert(m);
assert(j);
if (j->transaction_prev)
j->transaction_prev->transaction_next = j->transaction_next;
else if (j->transaction_next)
hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
else
hashmap_remove_value(m->transaction_jobs, j->unit, j);
if (j->transaction_next)
j->transaction_next->transaction_prev = j->transaction_prev;
j->transaction_prev = j->transaction_next = NULL;
while (j->subject_list)
job_dependency_free(j->subject_list);
while (j->object_list) {
Job *other = j->object_list->matters ? j->object_list->subject : NULL;
job_dependency_free(j->object_list);
if (other && delete_dependencies) {
log_debug("Deleting job %s/%s as dependency of job %s/%s",
other->unit->meta.id, job_type_to_string(other->type),
j->unit->meta.id, job_type_to_string(j->type));
transaction_delete_job(m, other, delete_dependencies);
}
}
}
static int transaction_add_job_and_dependencies(
Manager *m,
JobType type,
Unit *unit,
Job *by,
bool matters,
bool override,
bool conflicts,
DBusError *e,
Job **_ret) {
Job *ret;
Iterator i;
Unit *dep;
int r;
bool is_new;
assert(m);
assert(type < _JOB_TYPE_MAX);
assert(unit);
if (unit->meta.load_state != UNIT_LOADED && unit->meta.load_state != UNIT_FAILED) {
dbus_set_error(e, BUS_ERROR_LOAD_FAILED, "Unit %s is not loaded properly.", unit->meta.id);
return -EINVAL;
}
if (type != JOB_STOP && unit->meta.load_state == UNIT_FAILED) {
dbus_set_error(e, BUS_ERROR_LOAD_FAILED, "Unit %s failed to load: %s. You might find more information in the logs.",
unit->meta.id,
strerror(-unit->meta.load_error));
return -EINVAL;
}
if (!unit_job_is_applicable(unit, type)) {
dbus_set_error(e, BUS_ERROR_JOB_TYPE_NOT_APPLICABLE, "Job type %s is not applicable for unit %s.", job_type_to_string(type), unit->meta.id);
return -EBADR;
}
/* First add the job. */
if (!(ret = transaction_add_one_job(m, type, unit, override, &is_new)))
return -ENOMEM;
/* Then, add a link to the job. */
if (!job_dependency_new(by, ret, matters, conflicts))
return -ENOMEM;
if (is_new) {
/* Finally, recursively add in all dependencies. */
if (type == JOB_START || type == JOB_RELOAD_OR_START) {
SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
goto fail;
SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !override, override, false, e, NULL)) < 0 && r != -EBADR) {
log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
dbus_error_free(e);
}
SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, false, false, e, NULL)) < 0) {
log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
dbus_error_free(e);
}
SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
goto fail;
SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !override, override, false, e, NULL)) < 0 && r != -EBADR) {
log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
dbus_error_free(e);
}
SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, true, e, NULL)) < 0 && r != -EBADR)
goto fail;
SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTED_BY], i)
if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
goto fail;
} else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
goto fail;
}
/* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
}
if (_ret)
*_ret = ret;
return 0;
fail:
return r;
}
static int transaction_add_isolate_jobs(Manager *m) {
Iterator i;
Unit *u;
char *k;
int r;
assert(m);
HASHMAP_FOREACH_KEY(u, k, m->units, i) {
/* ignore aliases */
if (u->meta.id != k)
continue;
if (UNIT_VTABLE(u)->no_isolate)
continue;
/* No need to stop inactive jobs */
if (UNIT_IS_INACTIVE_OR_MAINTENANCE(unit_active_state(u)))
continue;
/* Is there already something listed for this? */
if (hashmap_get(m->transaction_jobs, u))
continue;
if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, u, NULL, true, false, false, NULL, NULL)) < 0)
log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->meta.id, strerror(-r));
}
return 0;
}
int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, DBusError *e, Job **_ret) {
int r;
Job *ret;
assert(m);
assert(type < _JOB_TYPE_MAX);
assert(unit);
assert(mode < _JOB_MODE_MAX);
if (mode == JOB_ISOLATE && type != JOB_START) {
dbus_set_error(e, BUS_ERROR_INVALID_JOB_MODE, "Isolate is only valid for start.");
return -EINVAL;
}
log_debug("Trying to enqueue job %s/%s", unit->meta.id, job_type_to_string(type));
if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, override, false, e, &ret)) < 0) {
transaction_abort(m);
return r;
}
if (mode == JOB_ISOLATE)
if ((r = transaction_add_isolate_jobs(m)) < 0) {
transaction_abort(m);
return r;
}
if ((r = transaction_activate(m, mode, e)) < 0)
return r;
log_debug("Enqueued job %s/%s as %u", unit->meta.id, job_type_to_string(type), (unsigned) ret->id);
if (_ret)
*_ret = ret;
return 0;
}
int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool override, DBusError *e, Job **_ret) {
Unit *unit;
int r;
assert(m);
assert(type < _JOB_TYPE_MAX);
assert(name);
assert(mode < _JOB_MODE_MAX);
if ((r = manager_load_unit(m, name, NULL, NULL, &unit)) < 0)
return r;
return manager_add_job(m, type, unit, mode, override, e, _ret);
}
Job *manager_get_job(Manager *m, uint32_t id) {
assert(m);
return hashmap_get(m->jobs, UINT32_TO_PTR(id));
}
Unit *manager_get_unit(Manager *m, const char *name) {
assert(m);
assert(name);
return hashmap_get(m->units, name);
}
unsigned manager_dispatch_load_queue(Manager *m) {
Meta *meta;
unsigned n = 0;
assert(m);
/* Make sure we are not run recursively */
if (m->dispatching_load_queue)
return 0;
m->dispatching_load_queue = true;
/* Dispatches the load queue. Takes a unit from the queue and
* tries to load its data until the queue is empty */
while ((meta = m->load_queue)) {
assert(meta->in_load_queue);
unit_load((Unit*) meta);
n++;
}
m->dispatching_load_queue = false;
return n;
}
int manager_load_unit_prepare(Manager *m, const char *name, const char *path, DBusError *e, Unit **_ret) {
Unit *ret;
int r;
assert(m);
assert(name || path);
/* This will prepare the unit for loading, but not actually
* load anything from disk. */
if (path && !is_path(path)) {
dbus_set_error(e, BUS_ERROR_INVALID_PATH, "Path %s is not absolute.", path);
return -EINVAL;
}
if (!name)
name = file_name_from_path(path);
if (!unit_name_is_valid(name)) {
dbus_set_error(e, BUS_ERROR_INVALID_NAME, "Unit name %s is not valid.", name);
return -EINVAL;
}
if ((ret = manager_get_unit(m, name))) {
*_ret = ret;
return 1;
}
if (!(ret = unit_new(m)))
return -ENOMEM;
if (path)
if (!(ret->meta.fragment_path = strdup(path))) {
unit_free(ret);
return -ENOMEM;
}
if ((r = unit_add_name(ret, name)) < 0) {
unit_free(ret);
return r;
}
unit_add_to_load_queue(ret);
unit_add_to_dbus_queue(ret);
unit_add_to_gc_queue(ret);
if (_ret)
*_ret = ret;
return 0;
}
int manager_load_unit(Manager *m, const char *name, const char *path, DBusError *e, Unit **_ret) {
int r;
assert(m);
/* This will load the service information files, but not actually
* start any services or anything. */
if ((r = manager_load_unit_prepare(m, name, path, e, _ret)) != 0)
return r;
manager_dispatch_load_queue(m);
if (_ret)
*_ret = unit_follow_merge(*_ret);
return 0;
}
void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
Iterator i;
Job *j;
assert(s);
assert(f);
HASHMAP_FOREACH(j, s->jobs, i)
job_dump(j, f, prefix);
}
void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
Iterator i;
Unit *u;
const char *t;
assert(s);
assert(f);
HASHMAP_FOREACH_KEY(u, t, s->units, i)
if (u->meta.id == t)
unit_dump(u, f, prefix);
}
void manager_clear_jobs(Manager *m) {
Job *j;
assert(m);
transaction_abort(m);
while ((j = hashmap_first(m->jobs)))
job_free(j);
}
unsigned manager_dispatch_run_queue(Manager *m) {
Job *j;
unsigned n = 0;
if (m->dispatching_run_queue)
return 0;
m->dispatching_run_queue = true;
while ((j = m->run_queue)) {
assert(j->installed);
assert(j->in_run_queue);
job_run_and_invalidate(j);
n++;
}
m->dispatching_run_queue = false;
return n;
}
unsigned manager_dispatch_dbus_queue(Manager *m) {
Job *j;
Meta *meta;
unsigned n = 0;
assert(m);
if (m->dispatching_dbus_queue)
return 0;
m->dispatching_dbus_queue = true;
while ((meta = m->dbus_unit_queue)) {
assert(meta->in_dbus_queue);
bus_unit_send_change_signal((Unit*) meta);
n++;
}
while ((j = m->dbus_job_queue)) {
assert(j->in_dbus_queue);
bus_job_send_change_signal(j);
n++;
}
m->dispatching_dbus_queue = false;
return n;
}
static int manager_process_notify_fd(Manager *m) {
ssize_t n;
assert(m);
for (;;) {
char buf[4096];
struct msghdr msghdr;
struct iovec iovec;
struct ucred *ucred;
union {
struct cmsghdr cmsghdr;
uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
} control;
Unit *u;
char **tags;
zero(iovec);
iovec.iov_base = buf;
iovec.iov_len = sizeof(buf)-1;
zero(control);
zero(msghdr);
msghdr.msg_iov = &iovec;
msghdr.msg_iovlen = 1;
msghdr.msg_control = &control;
msghdr.msg_controllen = sizeof(control);
if ((n = recvmsg(m->notify_watch.fd, &msghdr, MSG_DONTWAIT)) <= 0) {
if (n >= 0)
return -EIO;
if (errno == EAGAIN || errno == EINTR)
break;
return -errno;
}
if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) ||
control.cmsghdr.cmsg_level != SOL_SOCKET ||
control.cmsghdr.cmsg_type != SCM_CREDENTIALS ||
control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
log_warning("Received notify message without credentials. Ignoring.");
continue;
}
ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
if (!(u = hashmap_get(m->watch_pids, LONG_TO_PTR(ucred->pid))))
if (!(u = cgroup_unit_by_pid(m, ucred->pid))) {
log_warning("Cannot find unit for notify message of PID %lu.", (unsigned long) ucred->pid);
continue;
}
assert((size_t) n < sizeof(buf));
buf[n] = 0;
if (!(tags = strv_split(buf, "\n\r")))
return -ENOMEM;
log_debug("Got notification message for unit %s", u->meta.id);
if (UNIT_VTABLE(u)->notify_message)
UNIT_VTABLE(u)->notify_message(u, ucred->pid, tags);
strv_free(tags);
}
return 0;
}
static int manager_dispatch_sigchld(Manager *m) {
assert(m);
for (;;) {
siginfo_t si;
Unit *u;
int r;
zero(si);
/* First we call waitd() for a PID and do not reap the
* zombie. That way we can still access /proc/$PID for
* it while it is a zombie. */
if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG|WNOWAIT) < 0) {
if (errno == ECHILD)
break;
if (errno == EINTR)
continue;
return -errno;
}
if (si.si_pid <= 0)
break;
if (si.si_code == CLD_EXITED || si.si_code == CLD_KILLED || si.si_code == CLD_DUMPED) {
char *name = NULL;
get_process_name(si.si_pid, &name);
log_debug("Got SIGCHLD for process %lu (%s)", (unsigned long) si.si_pid, strna(name));
free(name);
}
/* Let's flush any message the dying child might still
* have queued for us. This ensures that the process
* still exists in /proc so that we can figure out
* which cgroup and hence unit it belongs to. */
if ((r = manager_process_notify_fd(m)) < 0)
return r;
/* And now figure out the unit this belongs to */
if (!(u = hashmap_get(m->watch_pids, LONG_TO_PTR(si.si_pid))))
u = cgroup_unit_by_pid(m, si.si_pid);
/* And now, we actually reap the zombie. */
if (waitid(P_PID, si.si_pid, &si, WEXITED) < 0) {
if (errno == EINTR)
continue;
return -errno;
}
if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
continue;
log_debug("Child %lu died (code=%s, status=%i/%s)",
(long unsigned) si.si_pid,
sigchld_code_to_string(si.si_code),
si.si_status,
strna(si.si_code == CLD_EXITED
? exit_status_to_string(si.si_status, EXIT_STATUS_FULL)
: signal_to_string(si.si_status)));
if (!u)
continue;
log_debug("Child %lu belongs to %s", (long unsigned) si.si_pid, u->meta.id);
hashmap_remove(m->watch_pids, LONG_TO_PTR(si.si_pid));
UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
}
return 0;
}
static int manager_start_target(Manager *m, const char *name, JobMode mode) {
int r;
DBusError error;
dbus_error_init(&error);
log_info("Activating special unit %s", name);
if ((r = manager_add_job_by_name(m, JOB_START, name, mode, true, &error, NULL)) < 0)
log_error("Failed to enqueue %s job: %s", name, bus_error(&error, r));
dbus_error_free(&error);
return r;
}
static int manager_process_signal_fd(Manager *m) {
ssize_t n;
struct signalfd_siginfo sfsi;
bool sigchld = false;
assert(m);
for (;;) {
if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
if (n >= 0)
return -EIO;
if (errno == EAGAIN)
break;
return -errno;
}
log_debug("Received SIG%s", strna(signal_to_string(sfsi.ssi_signo)));
switch (sfsi.ssi_signo) {
case SIGCHLD:
sigchld = true;
break;
case SIGTERM:
if (m->running_as == MANAGER_SYSTEM) {
/* This is for compatibility with the
* original sysvinit */
m->exit_code = MANAGER_REEXECUTE;
break;
}
/* Fall through */
case SIGINT:
if (m->running_as == MANAGER_SYSTEM) {
manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET, JOB_REPLACE);
break;
}
/* Run the exit target if there is one, if not, just exit. */
if (manager_start_target(m, SPECIAL_EXIT_SERVICE, JOB_REPLACE) < 0) {
m->exit_code = MANAGER_EXIT;
return 0;
}
break;
case SIGWINCH:
if (m->running_as == MANAGER_SYSTEM)
manager_start_target(m, SPECIAL_KBREQUEST_TARGET, JOB_REPLACE);
/* This is a nop on non-init */
break;
case SIGPWR:
if (m->running_as == MANAGER_SYSTEM)
manager_start_target(m, SPECIAL_SIGPWR_TARGET, JOB_REPLACE);
/* This is a nop on non-init */
break;
case SIGUSR1: {
Unit *u;
u = manager_get_unit(m, SPECIAL_DBUS_SERVICE);
if (!u || UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u))) {
log_info("Trying to reconnect to bus...");
bus_init(m);
}
if (!u || !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u))) {
log_info("Loading D-Bus service...");
manager_start_target(m, SPECIAL_DBUS_SERVICE, JOB_REPLACE);
}
break;
}
case SIGUSR2: {
FILE *f;
char *dump = NULL;
size_t size;
if (!(f = open_memstream(&dump, &size))) {
log_warning("Failed to allocate memory stream.");
break;
}
manager_dump_units(m, f, "\t");
manager_dump_jobs(m, f, "\t");
if (ferror(f)) {
fclose(f);
free(dump);
log_warning("Failed to write status stream");
break;
}
fclose(f);
log_dump(LOG_INFO, dump);
free(dump);
break;
}
case SIGHUP:
m->exit_code = MANAGER_RELOAD;
break;
default: {
static const char * const table[] = {
[0] = SPECIAL_DEFAULT_TARGET,
[1] = SPECIAL_RESCUE_TARGET,
[2] = SPECIAL_EMERGENCY_TARGET,
[3] = SPECIAL_HALT_TARGET,
[4] = SPECIAL_POWEROFF_TARGET,
[5] = SPECIAL_REBOOT_TARGET
};
if ((int) sfsi.ssi_signo >= SIGRTMIN+0 &&
(int) sfsi.ssi_signo < SIGRTMIN+(int) ELEMENTSOF(table)) {
manager_start_target(m, table[sfsi.ssi_signo - SIGRTMIN],
(sfsi.ssi_signo == 1 || sfsi.ssi_signo == 2) ? JOB_ISOLATE : JOB_REPLACE);
break;
}
log_warning("Got unhandled signal <%s>.", strna(signal_to_string(sfsi.ssi_signo)));
}
}
}
if (sigchld)
return manager_dispatch_sigchld(m);
return 0;
}
static int process_event(Manager *m, struct epoll_event *ev) {
int r;
Watch *w;
assert(m);
assert(ev);
assert(w = ev->data.ptr);
switch (w->type) {
case WATCH_SIGNAL:
/* An incoming signal? */
if (ev->events != EPOLLIN)
return -EINVAL;
if ((r = manager_process_signal_fd(m)) < 0)
return r;
break;
case WATCH_NOTIFY:
/* An incoming daemon notification event? */
if (ev->events != EPOLLIN)
return -EINVAL;
if ((r = manager_process_notify_fd(m)) < 0)
return r;
break;
case WATCH_FD:
/* Some fd event, to be dispatched to the units */
UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w);
break;
case WATCH_UNIT_TIMER:
case WATCH_JOB_TIMER: {
uint64_t v;
ssize_t k;
/* Some timer event, to be dispatched to the units */
if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
if (k < 0 && (errno == EINTR || errno == EAGAIN))
break;
return k < 0 ? -errno : -EIO;
}
if (w->type == WATCH_UNIT_TIMER)
UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w);
else
job_timer_event(w->data.job, v, w);
break;
}
case WATCH_MOUNT:
/* Some mount table change, intended for the mount subsystem */
mount_fd_event(m, ev->events);
break;
case WATCH_UDEV:
/* Some notification from udev, intended for the device subsystem */
device_fd_event(m, ev->events);
break;
case WATCH_DBUS_WATCH:
bus_watch_event(m, w, ev->events);
break;
case WATCH_DBUS_TIMEOUT:
bus_timeout_event(m, w, ev->events);
break;
default:
assert_not_reached("Unknown epoll event type.");
}
return 0;
}
int manager_loop(Manager *m) {
int r;
RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
assert(m);
m->exit_code = MANAGER_RUNNING;
/* Release the path cache */
set_free_free(m->unit_path_cache);
m->unit_path_cache = NULL;
/* There might still be some zombies hanging around from
* before we were exec()'ed. Leat's reap them */
if ((r = manager_dispatch_sigchld(m)) < 0)
return r;
while (m->exit_code == MANAGER_RUNNING) {
struct epoll_event event;
int n;
if (!ratelimit_test(&rl)) {
/* Yay, something is going seriously wrong, pause a little */
log_warning("Looping too fast. Throttling execution a little.");
sleep(1);
}
if (manager_dispatch_load_queue(m) > 0)
continue;
if (manager_dispatch_run_queue(m) > 0)
continue;
if (bus_dispatch(m) > 0)
continue;
if (manager_dispatch_cleanup_queue(m) > 0)
continue;
if (manager_dispatch_gc_queue(m) > 0)
continue;
if (manager_dispatch_dbus_queue(m) > 0)
continue;
if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
if (errno == EINTR)
continue;
return -errno;
}
assert(n == 1);
if ((r = process_event(m, &event)) < 0)
return r;
}
return m->exit_code;
}
int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
char *n;
Unit *u;
assert(m);
assert(s);
assert(_u);
if (!startswith(s, "/org/freedesktop/systemd1/unit/"))
return -EINVAL;
if (!(n = bus_path_unescape(s+31)))
return -ENOMEM;
u = manager_get_unit(m, n);
free(n);
if (!u)
return -ENOENT;
*_u = u;
return 0;
}
int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
Job *j;
unsigned id;
int r;
assert(m);
assert(s);
assert(_j);
if (!startswith(s, "/org/freedesktop/systemd1/job/"))
return -EINVAL;
if ((r = safe_atou(s + 30, &id)) < 0)
return r;
if (!(j = manager_get_job(m, id)))
return -ENOENT;
*_j = j;
return 0;
}
void manager_send_unit_audit(Manager *m, Unit *u, int type, bool success) {
#ifdef HAVE_AUDIT
char *p;
if (m->audit_fd < 0)
return;
/* Don't generate audit events if the service was already
* started and we're just deserializing */
if (m->n_deserializing > 0)
return;
if (!(p = unit_name_to_prefix_and_instance(u->meta.id))) {
log_error("Failed to allocate unit name for audit message: %s", strerror(ENOMEM));
return;
}
if (audit_log_user_comm_message(m->audit_fd, type, "", p, NULL, NULL, NULL, success) < 0)
log_error("Failed to send audit message: %m");
free(p);
#endif
}
void manager_dispatch_bus_name_owner_changed(
Manager *m,
const char *name,
const char* old_owner,
const char *new_owner) {
Unit *u;
assert(m);
assert(name);
if (!(u = hashmap_get(m->watch_bus, name)))
return;
UNIT_VTABLE(u)->bus_name_owner_change(u, name, old_owner, new_owner);
}
void manager_dispatch_bus_query_pid_done(
Manager *m,
const char *name,
pid_t pid) {
Unit *u;
assert(m);
assert(name);
assert(pid >= 1);
if (!(u = hashmap_get(m->watch_bus, name)))
return;
UNIT_VTABLE(u)->bus_query_pid_done(u, name, pid);
}
int manager_open_serialization(Manager *m, FILE **_f) {
char *path;
mode_t saved_umask;
int fd;
FILE *f;
assert(_f);
if (m->running_as == MANAGER_SYSTEM) {
mkdir_p("/dev/.systemd", 0755);
if (asprintf(&path, "/dev/.systemd/dump-%lu-XXXXXX", (unsigned long) getpid()) < 0)
return -ENOMEM;
} else {
if (asprintf(&path, "/tmp/systemd-dump-%lu-XXXXXX", (unsigned long) getpid()) < 0)
return -ENOMEM;
}
saved_umask = umask(0077);
fd = mkostemp(path, O_RDWR|O_CLOEXEC);
umask(saved_umask);
if (fd < 0) {
free(path);
return -errno;
}
unlink(path);
log_debug("Serializing state to %s", path);
free(path);
if (!(f = fdopen(fd, "w+")) < 0)
return -errno;
*_f = f;
return 0;
}
int manager_serialize(Manager *m, FILE *f, FDSet *fds) {
Iterator i;
Unit *u;
const char *t;
int r;
assert(m);
assert(f);
assert(fds);
fprintf(f, "startup-timestamp=%llu %llu\n\n",
(unsigned long long) m->startup_timestamp.realtime,
(unsigned long long) m->startup_timestamp.monotonic);
HASHMAP_FOREACH_KEY(u, t, m->units, i) {
if (u->meta.id != t)
continue;
if (!unit_can_serialize(u))
continue;
/* Start marker */
fputs(u->meta.id, f);
fputc('\n', f);
if ((r = unit_serialize(u, f, fds)) < 0)
return r;
}
if (ferror(f))
return -EIO;
return 0;
}
int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
int r = 0;
assert(m);
assert(f);
log_debug("Deserializing state...");
m->n_deserializing ++;
for (;;) {
char line[1024], *l;
if (!fgets(line, sizeof(line), f)) {
if (feof(f))
r = 0;
else
r = -errno;
goto finish;
}
char_array_0(line);
l = strstrip(line);
if (l[0] == 0)
break;
if (startswith(l, "startup-timestamp=")) {
unsigned long long a, b;
if (sscanf(l+18, "%lli %llu", &a, &b) != 2)
log_debug("Failed to parse startup timestamp value %s", l+18);
else {
m->startup_timestamp.realtime = a;
m->startup_timestamp.monotonic = b;
}
} else
log_debug("Unknown serialization item '%s'", l);
}
for (;;) {
Unit *u;
char name[UNIT_NAME_MAX+2];
/* Start marker */
if (!fgets(name, sizeof(name), f)) {
if (feof(f))
r = 0;
else
r = -errno;
goto finish;
}
char_array_0(name);
if ((r = manager_load_unit(m, strstrip(name), NULL, NULL, &u)) < 0)
goto finish;
if ((r = unit_deserialize(u, f, fds)) < 0)
goto finish;
}
finish:
if (ferror(f)) {
r = -EIO;
goto finish;
}
assert(m->n_deserializing > 0);
m->n_deserializing --;
return r;
}
int manager_reload(Manager *m) {
int r, q;
FILE *f;
FDSet *fds;
assert(m);
if ((r = manager_open_serialization(m, &f)) < 0)
return r;
if (!(fds = fdset_new())) {
r = -ENOMEM;
goto finish;
}
if ((r = manager_serialize(m, f, fds)) < 0)
goto finish;
if (fseeko(f, 0, SEEK_SET) < 0) {
r = -errno;
goto finish;
}
/* From here on there is no way back. */
manager_clear_jobs_and_units(m);
/* Find new unit paths */
lookup_paths_free(&m->lookup_paths);
if ((q = lookup_paths_init(&m->lookup_paths, m->running_as)) < 0)
r = q;
m->n_deserializing ++;
/* First, enumerate what we can from all config files */
if ((q = manager_enumerate(m)) < 0)
r = q;
/* Second, deserialize our stored data */
if ((q = manager_deserialize(m, f, fds)) < 0)
r = q;
fclose(f);
f = NULL;
/* Third, fire things up! */
if ((q = manager_coldplug(m)) < 0)
r = q;
assert(m->n_deserializing > 0);
m->n_deserializing ++;
finish:
if (f)
fclose(f);
if (fds)
fdset_free(fds);
return r;
}
bool manager_is_booting_or_shutting_down(Manager *m) {
Unit *u;
assert(m);
/* Is the initial job still around? */
if (manager_get_job(m, 1))
return true;
/* Is there a job for the shutdown target? */
if (((u = manager_get_unit(m, SPECIAL_SHUTDOWN_TARGET))))
return !!u->meta.job;
return false;
}
void manager_reset_maintenance(Manager *m) {
Unit *u;
Iterator i;
assert(m);
HASHMAP_FOREACH(u, m->units, i)
unit_reset_maintenance(u);
}
static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
[MANAGER_SYSTEM] = "system",
[MANAGER_SESSION] = "session"
};
DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);
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