blob: ae77bae65edcd6214be64d0442927bdef54d0f25 [file] [log] [blame] [raw]
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <fcntl.h>
#include <unistd.h>
#include "alloc-util.h"
#include "bus-common-errors.h"
#include "bus-error.h"
#include "dbus-unit.h"
#include "strv.h"
#include "terminal-util.h"
#include "transaction.h"
static void transaction_unlink_job(Transaction *tr, Job *j, bool delete_dependencies);
static void transaction_delete_job(Transaction *tr, Job *j, bool delete_dependencies) {
assert(tr);
assert(j);
/* Deletes one job from the transaction */
transaction_unlink_job(tr, j, delete_dependencies);
job_free(j);
}
static void transaction_delete_unit(Transaction *tr, Unit *u) {
Job *j;
/* Deletes all jobs associated with a certain unit from the
* transaction */
while ((j = hashmap_get(tr->jobs, u)))
transaction_delete_job(tr, j, true);
}
void transaction_abort(Transaction *tr) {
Job *j;
assert(tr);
while ((j = hashmap_first(tr->jobs)))
transaction_delete_job(tr, j, false);
assert(hashmap_isempty(tr->jobs));
}
static void transaction_find_jobs_that_matter_to_anchor(Job *j, unsigned generation) {
JobDependency *l;
/* 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. */
j->matters_to_anchor = true;
j->generation = generation;
LIST_FOREACH(subject, l, j->subject_list) {
/* This link does not matter */
if (!l->matters)
continue;
/* This unit has already been marked */
if (l->object->generation == generation)
continue;
transaction_find_jobs_that_matter_to_anchor(l->object, generation);
}
}
static void transaction_merge_and_delete_job(Transaction *tr, 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 'other'. */
j->type = t;
j->state = JOB_WAITING;
j->irreversible = j->irreversible || other->irreversible;
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(tr, other, true);
}
_pure_ 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(Transaction *tr, Job *j) {
Job *k;
assert(j);
/* Tries to delete one item in the linked list
* j->transaction_next->transaction_next->... that conflicts
* with 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_unit_debug(j->unit,
"Looking at job %s/%s conflicted_by=%s",
j->unit->id, job_type_to_string(j->type),
yes_no(j->type == JOB_STOP && job_is_conflicted_by(j)));
log_unit_debug(k->unit,
"Looking at job %s/%s conflicted_by=%s",
k->unit->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_unit_debug(d->unit,
"Fixing conflicting jobs %s/%s,%s/%s by deleting job %s/%s",
j->unit->id, job_type_to_string(j->type),
k->unit->id, job_type_to_string(k->type),
d->unit->id, job_type_to_string(d->type));
transaction_delete_job(tr, d, true);
return 0;
}
return -EINVAL;
}
static int transaction_merge_jobs(Transaction *tr, sd_bus_error *e) {
Job *j;
int r;
assert(tr);
/* First step, check whether any of the jobs for one specific
* task conflict. If so, try to drop one of them. */
HASHMAP_FOREACH(j, tr->jobs) {
JobType t;
Job *k;
t = j->type;
LIST_FOREACH(transaction, k, j->transaction_next) {
if (job_type_merge_and_collapse(&t, k->type, j->unit) >= 0)
continue;
/* OK, we could not merge all jobs for this
* action. Let's see if we can get rid of one
* of them */
r = delete_one_unmergeable_job(tr, j);
if (r >= 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 */
return sd_bus_error_setf(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->id);
}
}
/* Second step, merge the jobs. */
HASHMAP_FOREACH(j, tr->jobs) {
JobType t = j->type;
Job *k;
/* Merge all transaction jobs for j->unit */
LIST_FOREACH(transaction, k, j->transaction_next)
assert_se(job_type_merge_and_collapse(&t, k->type, j->unit) == 0);
while ((k = j->transaction_next)) {
if (tr->anchor_job == k) {
transaction_merge_and_delete_job(tr, k, j, t);
j = k;
} else
transaction_merge_and_delete_job(tr, j, k, t);
}
assert(!j->transaction_next);
assert(!j->transaction_prev);
}
return 0;
}
static void transaction_drop_redundant(Transaction *tr) {
bool again;
/* Goes through the transaction and removes all jobs of the units whose jobs are all noops. If not
* all of a unit's jobs are redundant, they are kept. */
assert(tr);
do {
Job *j;
again = false;
HASHMAP_FOREACH(j, tr->jobs) {
bool keep = false;
Job *k;
LIST_FOREACH(transaction, k, j)
if (tr->anchor_job == k ||
!job_type_is_redundant(k->type, unit_active_state(k->unit)) ||
(k->unit->job && job_type_is_conflicting(k->type, k->unit->job->type))) {
keep = true;
break;
}
if (!keep) {
log_trace("Found redundant job %s/%s, dropping from transaction.",
j->unit->id, job_type_to_string(j->type));
transaction_delete_job(tr, j, false);
again = true;
break;
}
}
} while (again);
}
_pure_ 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 char* merge_unit_ids(const char* unit_log_field, char **pairs) {
char **unit_id, **job_type, *ans = NULL;
size_t alloc = 0, size = 0, next;
STRV_FOREACH_PAIR(unit_id, job_type, pairs) {
next = strlen(unit_log_field) + strlen(*unit_id);
if (!GREEDY_REALLOC(ans, alloc, size + next + 1))
return mfree(ans);
sprintf(ans + size, "%s%s", unit_log_field, *unit_id);
if (*(unit_id+1))
ans[size + next] = '\n';
size += next + 1;
}
return ans;
}
static int transaction_verify_order_one(Transaction *tr, Job *j, Job *from, unsigned generation, sd_bus_error *e) {
Unit *u;
void *v;
int r;
static const UnitDependency directions[] = {
UNIT_BEFORE,
UNIT_AFTER,
};
size_t d;
assert(tr);
assert(j);
assert(!j->transaction_prev);
/* Does a recursive sweep through the ordering graph, looking
* for a cycle. If we find a cycle we try to break it. */
/* Have we seen this before? */
if (j->generation == generation) {
Job *k, *delete = NULL;
_cleanup_free_ char **array = NULL, *unit_ids = NULL;
char **unit_id, **job_type;
/* 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. */
for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) {
/* For logging below */
if (strv_push_pair(&array, k->unit->id, (char*) job_type_to_string(k->type)) < 0)
log_oom();
if (!delete && hashmap_get(tr->jobs, k->unit) && !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;
}
unit_ids = merge_unit_ids(j->manager->unit_log_field, array); /* ignore error */
STRV_FOREACH_PAIR(unit_id, job_type, array)
/* logging for j not k here to provide a consistent narrative */
log_struct(LOG_WARNING,
"MESSAGE=%s: Found %s on %s/%s",
j->unit->id,
unit_id == array ? "ordering cycle" : "dependency",
*unit_id, *job_type,
unit_ids);
if (delete) {
const char *status;
/* logging for j not k here to provide a consistent narrative */
log_struct(LOG_ERR,
"MESSAGE=%s: Job %s/%s deleted to break ordering cycle starting with %s/%s",
j->unit->id, delete->unit->id, job_type_to_string(delete->type),
j->unit->id, job_type_to_string(j->type),
unit_ids);
if (log_get_show_color())
status = ANSI_HIGHLIGHT_RED " SKIP " ANSI_NORMAL;
else
status = " SKIP ";
unit_status_printf(delete->unit,
STATUS_TYPE_NOTICE,
status,
"Ordering cycle found, skipping %s");
transaction_delete_unit(tr, delete->unit);
return -EAGAIN;
}
log_struct(LOG_ERR,
"MESSAGE=%s: Unable to break cycle starting with %s/%s",
j->unit->id, j->unit->id, job_type_to_string(j->type),
unit_ids);
return sd_bus_error_setf(e, BUS_ERROR_TRANSACTION_ORDER_IS_CYCLIC,
"Transaction order is cyclic. See system logs for details.");
}
/* 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;
/* Actual ordering of jobs depends on the unit ordering dependency and job types. We need to traverse
* the graph over 'before' edges in the actual job execution order. We traverse over both unit
* ordering dependencies and we test with job_compare() whether it is the 'before' edge in the job
* execution ordering. */
for (d = 0; d < ELEMENTSOF(directions); d++) {
HASHMAP_FOREACH_KEY(v, u, j->unit->dependencies[directions[d]]) {
Job *o;
/* Is there a job for this unit? */
o = hashmap_get(tr->jobs, u);
if (!o) {
/* Ok, there is no job for this in the
* transaction, but maybe there is already one
* running? */
o = u->job;
if (!o)
continue;
}
/* Cut traversing if the job j is not really *before* o. */
if (job_compare(j, o, directions[d]) >= 0)
continue;
r = transaction_verify_order_one(tr, o, j, generation, e);
if (r < 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(Transaction *tr, unsigned *generation, sd_bus_error *e) {
Job *j;
int r;
unsigned g;
assert(tr);
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, tr->jobs) {
r = transaction_verify_order_one(tr, j, NULL, g, e);
if (r < 0)
return r;
}
return 0;
}
static void transaction_collect_garbage(Transaction *tr) {
bool again;
assert(tr);
/* Drop jobs that are not required by any other job */
do {
Job *j;
again = false;
HASHMAP_FOREACH(j, tr->jobs) {
if (tr->anchor_job == j)
continue;
if (!j->object_list) {
log_trace("Garbage collecting job %s/%s", j->unit->id, job_type_to_string(j->type));
transaction_delete_job(tr, j, true);
again = true;
break;
}
log_trace("Keeping job %s/%s because of %s/%s",
j->unit->id, job_type_to_string(j->type),
j->object_list->subject ? j->object_list->subject->unit->id : "root",
j->object_list->subject ? job_type_to_string(j->object_list->subject->type) : "root");
}
} while (again);
}
static int transaction_is_destructive(Transaction *tr, JobMode mode, sd_bus_error *e) {
Job *j;
assert(tr);
/* Checks whether applying this transaction means that
* existing jobs would be replaced */
HASHMAP_FOREACH(j, tr->jobs) {
/* Assume merged */
assert(!j->transaction_prev);
assert(!j->transaction_next);
if (j->unit->job && (mode == JOB_FAIL || j->unit->job->irreversible) &&
job_type_is_conflicting(j->unit->job->type, j->type))
return sd_bus_error_setf(e, BUS_ERROR_TRANSACTION_IS_DESTRUCTIVE,
"Transaction for %s/%s is destructive (%s has '%s' job queued, but '%s' is included in transaction).",
tr->anchor_job->unit->id, job_type_to_string(tr->anchor_job->type),
j->unit->id, job_type_to_string(j->unit->job->type), job_type_to_string(j->type));
}
return 0;
}
static void transaction_minimize_impact(Transaction *tr) {
Job *j;
assert(tr);
/* Drops all unnecessary jobs that reverse already active jobs
* or that stop a running service. */
rescan:
HASHMAP_FOREACH(j, tr->jobs) {
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->job &&
job_type_is_conflicting(j->type, j->unit->job->type);
if (!stops_running_service && !changes_existing_job)
continue;
if (stops_running_service)
log_unit_debug(j->unit,
"%s/%s would stop a running service.",
j->unit->id, job_type_to_string(j->type));
if (changes_existing_job)
log_unit_debug(j->unit,
"%s/%s would change existing job.",
j->unit->id, job_type_to_string(j->type));
/* Ok, let's get rid of this */
log_unit_debug(j->unit,
"Deleting %s/%s to minimize impact.",
j->unit->id, job_type_to_string(j->type));
transaction_delete_job(tr, j, true);
goto rescan;
}
}
}
static int transaction_apply(
Transaction *tr,
Manager *m,
JobMode mode,
Set *affected_jobs) {
Job *j;
int r;
/* Moves the transaction jobs to the set of active jobs */
if (IN_SET(mode, JOB_ISOLATE, JOB_FLUSH)) {
/* When isolating first kill all installed jobs which
* aren't part of the new transaction */
HASHMAP_FOREACH(j, m->jobs) {
assert(j->installed);
if (j->unit->ignore_on_isolate)
continue;
if (hashmap_get(tr->jobs, j->unit))
continue;
/* Not invalidating recursively. Avoids triggering
* OnFailure= actions of dependent jobs. Also avoids
* invalidating our iterator. */
job_finish_and_invalidate(j, JOB_CANCELED, false, false);
}
}
HASHMAP_FOREACH(j, tr->jobs) {
/* Assume merged */
assert(!j->transaction_prev);
assert(!j->transaction_next);
r = hashmap_ensure_allocated(&m->jobs, NULL);
if (r < 0)
return r;
r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j);
if (r < 0)
goto rollback;
}
while ((j = hashmap_steal_first(tr->jobs))) {
Job *installed_job;
/* Clean the job dependencies */
transaction_unlink_job(tr, j, false);
installed_job = job_install(j);
if (installed_job != j) {
/* j has been merged into a previously installed job */
if (tr->anchor_job == j)
tr->anchor_job = installed_job;
hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
job_free(j);
j = installed_job;
}
job_add_to_run_queue(j);
job_add_to_dbus_queue(j);
job_start_timer(j, false);
job_shutdown_magic(j);
/* When 'affected' is specified, let's track all in it all jobs that were touched because of
* this transaction. */
if (affected_jobs)
(void) set_put(affected_jobs, j);
}
return 0;
rollback:
HASHMAP_FOREACH(j, tr->jobs)
hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
return r;
}
int transaction_activate(
Transaction *tr,
Manager *m,
JobMode mode,
Set *affected_jobs,
sd_bus_error *e) {
Job *j;
int r;
unsigned generation = 1;
assert(tr);
/* This applies the changes recorded in tr->jobs to
* the actual list of jobs, if possible. */
/* Reset the generation counter of all installed jobs. The detection of cycles
* looks at installed jobs. If they had a non-zero generation from some previous
* walk of the graph, the algorithm would break. */
HASHMAP_FOREACH(j, m->jobs)
j->generation = 0;
/* First step: figure out which jobs matter */
transaction_find_jobs_that_matter_to_anchor(tr->anchor_job, 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. */
if (mode == JOB_FAIL)
transaction_minimize_impact(tr);
/* Third step: Drop redundant jobs */
transaction_drop_redundant(tr);
for (;;) {
/* Fourth step: Let's remove unneeded jobs that might
* be lurking. */
if (mode != JOB_ISOLATE)
transaction_collect_garbage(tr);
/* Fifth step: verify order makes sense and correct
* cycles if necessary and possible */
r = transaction_verify_order(tr, &generation, e);
if (r >= 0)
break;
if (r != -EAGAIN)
return log_warning_errno(r, "Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error_message(e, r));
/* 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 */
r = transaction_merge_jobs(tr, e);
if (r >= 0)
break;
if (r != -EAGAIN)
return log_warning_errno(r, "Requested transaction contains unmergeable jobs: %s", bus_error_message(e, r));
/* Seventh step: an entry got dropped, let's garbage
* collect its dependencies. */
if (mode != JOB_ISOLATE)
transaction_collect_garbage(tr);
/* 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(tr);
/* Ninth step: check whether we can actually apply this */
r = transaction_is_destructive(tr, mode, e);
if (r < 0)
return log_notice_errno(r, "Requested transaction contradicts existing jobs: %s", bus_error_message(e, r));
/* Tenth step: apply changes */
r = transaction_apply(tr, m, mode, affected_jobs);
if (r < 0)
return log_warning_errno(r, "Failed to apply transaction: %m");
assert(hashmap_isempty(tr->jobs));
if (!hashmap_isempty(m->jobs)) {
/* Are there any jobs now? Then make sure we have the
* idle pipe around. We don't really care too much
* whether this works or not, as the idle pipe is a
* feature for cosmetics, not actually useful for
* anything beyond that. */
if (m->idle_pipe[0] < 0 && m->idle_pipe[1] < 0 &&
m->idle_pipe[2] < 0 && m->idle_pipe[3] < 0) {
(void) pipe2(m->idle_pipe, O_NONBLOCK|O_CLOEXEC);
(void) pipe2(m->idle_pipe + 2, O_NONBLOCK|O_CLOEXEC);
}
}
return 0;
}
static Job* transaction_add_one_job(Transaction *tr, JobType type, Unit *unit, bool *is_new) {
Job *j, *f;
assert(tr);
assert(unit);
/* Looks for an existing prospective job and returns that. If
* it doesn't exist it is created and added to the prospective
* jobs list. */
f = hashmap_get(tr->jobs, unit);
LIST_FOREACH(transaction, j, f) {
assert(j->unit == unit);
if (j->type == type) {
if (is_new)
*is_new = false;
return j;
}
}
j = job_new(unit, type);
if (!j)
return NULL;
j->generation = 0;
j->marker = NULL;
j->matters_to_anchor = false;
j->irreversible = tr->irreversible;
LIST_PREPEND(transaction, f, j);
if (hashmap_replace(tr->jobs, unit, f) < 0) {
LIST_REMOVE(transaction, f, j);
job_free(j);
return NULL;
}
if (is_new)
*is_new = true;
log_trace("Added job %s/%s to transaction.", unit->id, job_type_to_string(type));
return j;
}
static void transaction_unlink_job(Transaction *tr, Job *j, bool delete_dependencies) {
assert(tr);
assert(j);
if (j->transaction_prev)
j->transaction_prev->transaction_next = j->transaction_next;
else if (j->transaction_next)
hashmap_replace(tr->jobs, j->unit, j->transaction_next);
else
hashmap_remove_value(tr->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_unit_debug(other->unit,
"Deleting job %s/%s as dependency of job %s/%s",
other->unit->id, job_type_to_string(other->type),
j->unit->id, job_type_to_string(j->type));
transaction_delete_job(tr, other, delete_dependencies);
}
}
}
void transaction_add_propagate_reload_jobs(Transaction *tr, Unit *unit, Job *by, bool ignore_order, sd_bus_error *e) {
JobType nt;
Unit *dep;
void *v;
int r;
assert(tr);
assert(unit);
HASHMAP_FOREACH_KEY(v, dep, unit->dependencies[UNIT_PROPAGATES_RELOAD_TO]) {
nt = job_type_collapse(JOB_TRY_RELOAD, dep);
if (nt == JOB_NOP)
continue;
r = transaction_add_job_and_dependencies(tr, nt, dep, by, false, false, false, ignore_order, e);
if (r < 0) {
log_unit_warning(dep,
"Cannot add dependency reload job, ignoring: %s",
bus_error_message(e, r));
sd_bus_error_free(e);
}
}
}
int transaction_add_job_and_dependencies(
Transaction *tr,
JobType type,
Unit *unit,
Job *by,
bool matters,
bool conflicts,
bool ignore_requirements,
bool ignore_order,
sd_bus_error *e) {
bool is_new;
Unit *dep;
Job *ret;
void *v;
int r;
assert(tr);
assert(type < _JOB_TYPE_MAX);
assert(type < _JOB_TYPE_MAX_IN_TRANSACTION);
assert(unit);
/* Before adding jobs for this unit, let's ensure that its state has been loaded
* This matters when jobs are spawned as part of coldplugging itself (see e. g. path_coldplug()).
* This way, we "recursively" coldplug units, ensuring that we do not look at state of
* not-yet-coldplugged units. */
if (MANAGER_IS_RELOADING(unit->manager))
unit_coldplug(unit);
if (by)
log_trace("Pulling in %s/%s from %s/%s", unit->id, job_type_to_string(type), by->unit->id, job_type_to_string(by->type));
/* Safety check that the unit is a valid state, i.e. not in UNIT_STUB or UNIT_MERGED which should only be set
* temporarily. */
if (!UNIT_IS_LOAD_COMPLETE(unit->load_state))
return sd_bus_error_setf(e, BUS_ERROR_LOAD_FAILED, "Unit %s is not loaded properly.", unit->id);
if (type != JOB_STOP) {
r = bus_unit_validate_load_state(unit, e);
/* The time-based cache allows to start new units without daemon-reload,
* but if they are already referenced (because of dependencies or ordering)
* then we have to force a load of the fragment. As an optimization, check
* first if anything in the usual paths was modified since the last time
* the cache was loaded. Also check if the last time an attempt to load the
* unit was made was before the most recent cache refresh, so that we know
* we need to try again — even if the cache is current, it might have been
* updated in a different context before we had a chance to retry loading
* this particular unit.
*
* Given building up the transaction is a synchronous operation, attempt
* to load the unit immediately. */
if (r < 0 && manager_unit_cache_should_retry_load(unit)) {
sd_bus_error_free(e);
unit->load_state = UNIT_STUB;
r = unit_load(unit);
if (r < 0 || unit->load_state == UNIT_STUB)
unit->load_state = UNIT_NOT_FOUND;
r = bus_unit_validate_load_state(unit, e);
}
if (r < 0)
return r;
}
if (!unit_job_is_applicable(unit, type))
return sd_bus_error_setf(e, BUS_ERROR_JOB_TYPE_NOT_APPLICABLE,
"Job type %s is not applicable for unit %s.",
job_type_to_string(type), unit->id);
/* First add the job. */
ret = transaction_add_one_job(tr, type, unit, &is_new);
if (!ret)
return -ENOMEM;
ret->ignore_order = ret->ignore_order || ignore_order;
/* Then, add a link to the job. */
if (by) {
if (!job_dependency_new(by, ret, matters, conflicts))
return -ENOMEM;
} else {
/* If the job has no parent job, it is the anchor job. */
assert(!tr->anchor_job);
tr->anchor_job = ret;
}
if (is_new && !ignore_requirements && type != JOB_NOP) {
Set *following;
/* If we are following some other unit, make sure we
* add all dependencies of everybody following. */
if (unit_following_set(ret->unit, &following) > 0) {
SET_FOREACH(dep, following) {
r = transaction_add_job_and_dependencies(tr, type, dep, ret, false, false, false, ignore_order, e);
if (r < 0) {
log_unit_full_errno(dep, r == -ERFKILL ? LOG_INFO : LOG_WARNING, r,
"Cannot add dependency job, ignoring: %s",
bus_error_message(e, r));
sd_bus_error_free(e);
}
}
set_free(following);
}
/* Finally, recursively add in all dependencies. */
if (IN_SET(type, JOB_START, JOB_RESTART)) {
HASHMAP_FOREACH_KEY(v, dep, ret->unit->dependencies[UNIT_REQUIRES]) {
r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, true, false, false, ignore_order, e);
if (r < 0) {
if (r != -EBADR) /* job type not applicable */
goto fail;
sd_bus_error_free(e);
}
}
HASHMAP_FOREACH_KEY(v, dep, ret->unit->dependencies[UNIT_BINDS_TO]) {
r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, true, false, false, ignore_order, e);
if (r < 0) {
if (r != -EBADR) /* job type not applicable */
goto fail;
sd_bus_error_free(e);
}
}
HASHMAP_FOREACH_KEY(v, dep, ret->unit->dependencies[UNIT_WANTS]) {
r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, false, false, false, ignore_order, e);
if (r < 0) {
/* unit masked, job type not applicable and unit not found are not considered as errors. */
log_unit_full_errno(dep,
IN_SET(r, -ERFKILL, -EBADR, -ENOENT) ? LOG_DEBUG : LOG_WARNING,
r, "Cannot add dependency job, ignoring: %s",
bus_error_message(e, r));
sd_bus_error_free(e);
}
}
HASHMAP_FOREACH_KEY(v, dep, ret->unit->dependencies[UNIT_REQUISITE]) {
r = transaction_add_job_and_dependencies(tr, JOB_VERIFY_ACTIVE, dep, ret, true, false, false, ignore_order, e);
if (r < 0) {
if (r != -EBADR) /* job type not applicable */
goto fail;
sd_bus_error_free(e);
}
}
HASHMAP_FOREACH_KEY(v, dep, ret->unit->dependencies[UNIT_CONFLICTS]) {
r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, true, true, false, ignore_order, e);
if (r < 0) {
if (r != -EBADR) /* job type not applicable */
goto fail;
sd_bus_error_free(e);
}
}
HASHMAP_FOREACH_KEY(v, dep, ret->unit->dependencies[UNIT_CONFLICTED_BY]) {
r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, false, false, false, ignore_order, e);
if (r < 0) {
log_unit_warning(dep,
"Cannot add dependency job, ignoring: %s",
bus_error_message(e, r));
sd_bus_error_free(e);
}
}
}
if (IN_SET(type, JOB_STOP, JOB_RESTART)) {
static const UnitDependency propagate_deps[] = {
UNIT_REQUIRED_BY,
UNIT_REQUISITE_OF,
UNIT_BOUND_BY,
UNIT_CONSISTS_OF,
};
JobType ptype;
unsigned j;
/* We propagate STOP as STOP, but RESTART only
* as TRY_RESTART, in order not to start
* dependencies that are not around. */
ptype = type == JOB_RESTART ? JOB_TRY_RESTART : type;
for (j = 0; j < ELEMENTSOF(propagate_deps); j++)
HASHMAP_FOREACH_KEY(v, dep, ret->unit->dependencies[propagate_deps[j]]) {
JobType nt;
nt = job_type_collapse(ptype, dep);
if (nt == JOB_NOP)
continue;
r = transaction_add_job_and_dependencies(tr, nt, dep, ret, true, false, false, ignore_order, e);
if (r < 0) {
if (r != -EBADR) /* job type not applicable */
goto fail;
sd_bus_error_free(e);
}
}
}
if (type == JOB_RELOAD)
transaction_add_propagate_reload_jobs(tr, ret->unit, ret, ignore_order, e);
/* JOB_VERIFY_ACTIVE requires no dependency handling */
}
return 0;
fail:
return r;
}
int transaction_add_isolate_jobs(Transaction *tr, Manager *m) {
Unit *u;
char *k;
int r;
assert(tr);
assert(m);
HASHMAP_FOREACH_KEY(u, k, m->units) {
/* ignore aliases */
if (u->id != k)
continue;
if (u->ignore_on_isolate)
continue;
/* No need to stop inactive jobs */
if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(u)) && !u->job)
continue;
/* Is there already something listed for this? */
if (hashmap_get(tr->jobs, u))
continue;
r = transaction_add_job_and_dependencies(tr, JOB_STOP, u, tr->anchor_job, true, false, false, false, NULL);
if (r < 0)
log_unit_warning_errno(u, r, "Cannot add isolate job, ignoring: %m");
}
return 0;
}
int transaction_add_triggering_jobs(Transaction *tr, Unit *u) {
void *v;
Unit *trigger;
int r;
assert(tr);
assert(u);
HASHMAP_FOREACH_KEY(v, trigger, u->dependencies[UNIT_TRIGGERED_BY]) {
/* No need to stop inactive jobs */
if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(trigger)) && !trigger->job)
continue;
/* Is there already something listed for this? */
if (hashmap_get(tr->jobs, trigger))
continue;
r = transaction_add_job_and_dependencies(tr, JOB_STOP, trigger, tr->anchor_job, true, false, false, false, NULL);
if (r < 0)
log_unit_warning_errno(u, r, "Cannot add triggered by job, ignoring: %m");
}
return 0;
}
Transaction *transaction_new(bool irreversible) {
Transaction *tr;
tr = new0(Transaction, 1);
if (!tr)
return NULL;
tr->jobs = hashmap_new(NULL);
if (!tr->jobs)
return mfree(tr);
tr->irreversible = irreversible;
return tr;
}
void transaction_free(Transaction *tr) {
assert(hashmap_isempty(tr->jobs));
hashmap_free(tr->jobs);
free(tr);
}