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Systemd/src/core/transaction.c
Lennart Poettering eef85c4a3f core: track why unit dependencies came to be 
This replaces the dependencies Set* objects by Hashmap* objects, where
the key is the depending Unit, and the value is a bitmask encoding why
the specific dependency was created.

The bitmask contains a number of different, defined bits, that indicate
why dependencies exist, for example whether they are created due to
explicitly configured deps in files, by udev rules or implicitly.

Note that memory usage is not increased by this change, even though we
store more information, as we manage to encode the bit mask inside the
value pointer each Hashmap entry contains.

Why this all? When we know how a dependency came to be, we can update
dependencies correctly when a configuration source changes but others
are left unaltered. Specifically:

1. We can fix UDEV_WANTS dependency generation: so far we kept adding
   dependencies configured that way, but if a device lost such a
   dependency we couldn't them again as there was no scheme for removing
   of dependencies in place.

2. We can implement "pin-pointed" reload of unit files. If we know what
   dependencies were created as result of configuration in a unit file,
   then we know what to flush out when we want to reload it.

3. It's useful for debugging: "systemd-analyze dump" now shows
   this information, helping substantially with understanding how
   systemd's dependency tree came to be the way it came to be.
2017-11-10 19:45:29 +01:00

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/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <fcntl.h>
#include <unistd.h>
#include "alloc-util.h"
#include "bus-common-errors.h"
#include "bus-error.h"
#include "terminal-util.h"
#include "transaction.h"
#include "dbus-unit.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;
Iterator i;
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, i) {
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, i) {
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) {
Job *j;
Iterator i;
/* 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);
rescan:
HASHMAP_FOREACH(j, tr->jobs, i) {
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)))
goto next_unit;
}
/* log_debug("Found redundant job %s/%s, dropping.", j->unit->id, job_type_to_string(j->type)); */
transaction_delete_job(tr, j, false);
goto rescan;
next_unit:;
}
}
_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)) {
free(ans);
return NULL;
}
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) {
Iterator i;
Unit *u;
void *v;
int r;
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, NULL);
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, NULL);
if (log_get_show_color())
status = ANSI_HIGHLIGHT_RED " SKIP " ANSI_NORMAL;
else
status = " SKIP ";
unit_status_printf(delete->unit, 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, NULL);
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;
/* We assume that the dependencies are bidirectional, and
* hence can ignore UNIT_AFTER */
HASHMAP_FOREACH_KEY(v, u, j->unit->dependencies[UNIT_BEFORE], i) {
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;
}
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;
Iterator i;
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, i) {
r = transaction_verify_order_one(tr, j, NULL, g, e);
if (r < 0)
return r;
}
return 0;
}
static void transaction_collect_garbage(Transaction *tr) {
Iterator i;
Job *j;
assert(tr);
/* Drop jobs that are not required by any other job */
rescan:
HASHMAP_FOREACH(j, tr->jobs, i) {
if (tr->anchor_job == j || j->object_list) {
/* log_debug("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"); */
continue;
}
/* log_debug("Garbage collecting job %s/%s", j->unit->id, job_type_to_string(j->type)); */
transaction_delete_job(tr, j, true);
goto rescan;
}
}
static int transaction_is_destructive(Transaction *tr, JobMode mode, sd_bus_error *e) {
Iterator i;
Job *j;
assert(tr);
/* Checks whether applying this transaction means that
* existing jobs would be replaced */
HASHMAP_FOREACH(j, tr->jobs, i) {
/* 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 is destructive.");
}
return 0;
}
static void transaction_minimize_impact(Transaction *tr) {
Job *j;
Iterator i;
assert(tr);
/* Drops all unnecessary jobs that reverse already active jobs
* or that stop a running service. */
rescan:
HASHMAP_FOREACH(j, tr->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->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) {
Iterator i;
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, i) {
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, i) {
/* Assume merged */
assert(!j->transaction_prev);
assert(!j->transaction_next);
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);
}
return 0;
rollback:
HASHMAP_FOREACH(j, tr->jobs, i)
hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
return r;
}
int transaction_activate(Transaction *tr, Manager *m, JobMode mode, sd_bus_error *e) {
Iterator i;
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, i)
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) {
log_warning("Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error_message(e, r));
return 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) {
log_warning("Requested transaction contains unmergeable jobs: %s", bus_error_message(e, r));
return 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) {
log_notice("Requested transaction contradicts existing jobs: %s", bus_error_message(e, r));
return r;
}
/* Tenth step: apply changes */
r = transaction_apply(tr, m, mode);
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_debug("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) {
Iterator i;
JobType nt;
Unit *dep;
void *v;
int r;
assert(tr);
assert(unit);
HASHMAP_FOREACH_KEY(v, dep, unit->dependencies[UNIT_PROPAGATES_RELOAD_TO], i) {
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;
Iterator i;
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);
/* log_debug("Pulling in %s/%s from %s/%s", */
/* unit->id, job_type_to_string(type), */
/* by ? by->unit->id : "NA", */
/* by ? job_type_to_string(by->type) : "NA"); */
if (!IN_SET(unit->load_state, UNIT_LOADED, UNIT_ERROR, UNIT_NOT_FOUND, UNIT_MASKED))
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_check_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, i) {
r = transaction_add_job_and_dependencies(tr, type, dep, ret, false, false, false, ignore_order, e);
if (r < 0) {
log_unit_full(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], i) {
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], i) {
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], i) {
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(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], i) {
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], i) {
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], i) {
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]], i) {
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_STARTED require no dependency handling */
}
return 0;
fail:
return r;
}
int transaction_add_isolate_jobs(Transaction *tr, Manager *m) {
Iterator i;
Unit *u;
char *k;
int r;
assert(tr);
assert(m);
HASHMAP_FOREACH_KEY(u, k, m->units, i) {
/* 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;
}
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);
}
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