Commit 5de9682c authored by Lennart Poettering's avatar Lennart Poettering
Browse files

unit: introduce OnFailure dependencies to activate units on failure of other...

unit: introduce OnFailure dependencies to activate units on failure of other units, as a way to implement an automatic rescue shell
parent 45fb0699
......@@ -70,6 +70,7 @@
" <property name=\"Conflicts\" type=\"as\" access=\"read\"/>\n" \
" <property name=\"Before\" type=\"as\" access=\"read\"/>\n" \
" <property name=\"After\" type=\"as\" access=\"read\"/>\n" \
" <property name=\"OnFailure\" type=\"as\" access=\"read\"/>\n" \
" <property name=\"Description\" type=\"s\" access=\"read\"/>\n" \
" <property name=\"LoadState\" type=\"s\" access=\"read\"/>\n" \
" <property name=\"ActiveState\" type=\"s\" access=\"read\"/>\n" \
......@@ -105,6 +106,7 @@
{ "org.freedesktop.systemd1.Unit", "Conflicts", bus_unit_append_dependencies, "as", u->meta.dependencies[UNIT_CONFLICTS] }, \
{ "org.freedesktop.systemd1.Unit", "Before", bus_unit_append_dependencies, "as", u->meta.dependencies[UNIT_BEFORE] }, \
{ "org.freedesktop.systemd1.Unit", "After", bus_unit_append_dependencies, "as", u->meta.dependencies[UNIT_AFTER] }, \
{ "org.freedesktop.systemd1.Unit", "OnFailure", bus_unit_append_dependencies, "as", u->meta.dependencies[UNIT_ON_FAILURE] }, \
{ "org.freedesktop.systemd1.Unit", "Description", bus_unit_append_description, "s", u }, \
{ "org.freedesktop.systemd1.Unit", "LoadState", bus_unit_append_load_state, "s", &u->meta.load_state }, \
{ "org.freedesktop.systemd1.Unit", "ActiveState", bus_unit_append_active_state, "s", u }, \
......
......@@ -987,9 +987,6 @@ void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
u->meta.active_exit_timestamp = ts;
if (ns != os && ns == UNIT_MAINTENANCE)
log_notice("Unit %s entered maintenance state.", u->meta.id);
if (UNIT_IS_INACTIVE_OR_MAINTENANCE(ns))
cgroup_bonding_trim_list(u->meta.cgroup_bondings, true);
......@@ -1072,6 +1069,16 @@ void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns) {
retroactively_stop_dependencies(u);
}
if (ns != os && ns == UNIT_MAINTENANCE) {
Iterator i;
Unit *other;
SET_FOREACH(other, u->meta.dependencies[UNIT_ON_FAILURE], i)
manager_add_job(u->meta.manager, JOB_START, other, JOB_REPLACE, true, NULL, NULL);
log_notice("Unit %s entered maintenance state.", u->meta.id);
}
/* Some names are special */
if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
if (unit_has_name(u, SPECIAL_DBUS_SERVICE)) {
......@@ -1294,6 +1301,7 @@ int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_referen
[UNIT_CONFLICTS] = UNIT_CONFLICTS,
[UNIT_BEFORE] = UNIT_AFTER,
[UNIT_AFTER] = UNIT_BEFORE,
[UNIT_ON_FAILURE] = _UNIT_DEPENDENCY_INVALID,
[UNIT_REFERENCES] = UNIT_REFERENCED_BY,
[UNIT_REFERENCED_BY] = UNIT_REFERENCES
};
......@@ -1301,7 +1309,6 @@ int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_referen
assert(u);
assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
assert(inverse_table[d] != _UNIT_DEPENDENCY_INVALID);
assert(other);
/* We won't allow dependencies on ourselves. We will not
......@@ -1317,8 +1324,11 @@ int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_referen
return -EINVAL;
}
if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0 ||
(r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
if ((r = set_ensure_allocated(&u->meta.dependencies[d], trivial_hash_func, trivial_compare_func)) < 0)
return r;
if (inverse_table[d] != _UNIT_DEPENDENCY_INVALID)
if ((r = set_ensure_allocated(&other->meta.dependencies[inverse_table[d]], trivial_hash_func, trivial_compare_func)) < 0)
return r;
if (add_reference)
......@@ -1329,6 +1339,7 @@ int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_referen
if ((q = set_put(u->meta.dependencies[d], other)) < 0)
return q;
if (inverse_table[d] != _UNIT_DEPENDENCY_INVALID)
if ((v = set_put(other->meta.dependencies[inverse_table[d]], u)) < 0) {
r = v;
goto fail;
......@@ -2097,7 +2108,8 @@ static const char* const unit_dependency_table[_UNIT_DEPENDENCY_MAX] = {
[UNIT_BEFORE] = "Before",
[UNIT_AFTER] = "After",
[UNIT_REFERENCES] = "References",
[UNIT_REFERENCED_BY] = "ReferencedBy"
[UNIT_REFERENCED_BY] = "ReferencedBy",
[UNIT_ON_FAILURE] = "OnFailure"
};
DEFINE_STRING_TABLE_LOOKUP(unit_dependency, UnitDependency);
......
......@@ -114,6 +114,9 @@ enum UnitDependency {
UNIT_BEFORE, /* inverse of 'before' is 'after' and vice versa */
UNIT_AFTER,
/* On Failure */
UNIT_ON_FAILURE,
/* Reference information for GC logic */
UNIT_REFERENCES, /* Inverse of 'references' is 'referenced_by' */
UNIT_REFERENCED_BY,
......
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