1
0
mirror of https://github.com/systemd/systemd.git synced 2024-12-22 17:35:35 +03:00

core: reload cache if it's dirty when starting a UNIT_NOT_FOUND unit

The time-based cache allows starting a new unit without an expensive
daemon-reload, unless there was already a reference to it because of
a dependency or ordering from another unit.
If the cache is out of date, check again if we can load the
fragment.
This commit is contained in:
Luca Boccassi 2020-05-07 23:26:53 +01:00 committed by Zbigniew Jędrzejewski-Szmek
parent 956508cb5d
commit d904afc730
7 changed files with 81 additions and 10 deletions

View File

@ -50,6 +50,7 @@
#include "io-util.h"
#include "label.h"
#include "locale-setup.h"
#include "load-fragment.h"
#include "log.h"
#include "macro.h"
#include "manager.h"
@ -1929,6 +1930,12 @@ unsigned manager_dispatch_load_queue(Manager *m) {
return n;
}
static bool manager_unit_cache_needs_refresh(Manager *m) {
assert(m);
return m->unit_cache_mtime > 0 && !lookup_paths_mtime_good(&m->lookup_paths, m->unit_cache_mtime);
}
int manager_load_unit_prepare(
Manager *m,
const char *name,
@ -1969,18 +1976,27 @@ int manager_load_unit_prepare(
ret = manager_get_unit(m, name);
if (ret) {
*_ret = ret;
return 1;
/* 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. */
if (ret->load_state == UNIT_NOT_FOUND && manager_unit_cache_needs_refresh(m))
ret->load_state = UNIT_STUB;
else {
*_ret = ret;
return 1;
}
} else {
ret = cleanup_ret = unit_new(m, unit_vtable[t]->object_size);
if (!ret)
return -ENOMEM;
}
ret = cleanup_ret = unit_new(m, unit_vtable[t]->object_size);
if (!ret)
return -ENOMEM;
if (path) {
ret->fragment_path = strdup(path);
if (!ret->fragment_path)
return -ENOMEM;
r = free_and_strdup(&ret->fragment_path, path);
if (r < 0)
return r;
}
r = unit_add_name(ret, name);

View File

@ -199,7 +199,7 @@ static bool lookup_paths_mtime_exclude(const LookupPaths *lp, const char *path)
streq_ptr(path, lp->runtime_control);
}
static bool lookup_paths_mtime_good(const LookupPaths *lp, usec_t mtime) {
bool lookup_paths_mtime_good(const LookupPaths *lp, usec_t mtime) {
char **dir;
STRV_FOREACH(dir, (char**) lp->search_path) {

View File

@ -43,6 +43,7 @@ bool unit_type_may_template(UnitType type) _const_;
int unit_symlink_name_compatible(const char *symlink, const char *target, bool instance_propagation);
int unit_validate_alias_symlink_and_warn(const char *filename, const char *target);
bool lookup_paths_mtime_good(const LookupPaths *lp, usec_t mtime);
int unit_file_build_name_map(
const LookupPaths *lp,
usec_t *ret_time,

View File

@ -0,0 +1 @@
../TEST-01-BASIC/Makefile

View File

@ -0,0 +1,8 @@
#!/usr/bin/env bash
# -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
# ex: ts=8 sw=4 sts=4 et filetype=sh
set -e
TEST_DESCRIPTION="test StartStopNoReload"
. $TEST_BASE_DIR/test-functions
do_test "$@" 48

View File

@ -0,0 +1,7 @@
[Unit]
Description=TEST-48-START-STOP-NO-RELOAD
[Service]
ExecStartPre=rm -f /failed /testok
ExecStart=/usr/lib/systemd/tests/testdata/units/%N.sh
Type=oneshot

38
test/units/testsuite-48.sh Executable file
View File

@ -0,0 +1,38 @@
#!/usr/bin/env bash
# -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
# ex: ts=8 sw=4 sts=4 et filetype=sh
set -ex
cat > /run/systemd/system/testservice-48.target <<EOF
[Unit]
Wants=testservice-48.service
EOF
systemctl daemon-reload
systemctl start testservice-48.target
# The filesystem on the test image, despite being ext4, seems to have a mtime
# granularity of one second, which means the manager's unit cache won't be
# marked as dirty when writing the unit file, unless we wait at least a full
# second after the previous daemon-reload.
# May 07 23:12:20 systemd-testsuite testsuite-48.sh[30]: + cat
# May 07 23:12:20 systemd-testsuite testsuite-48.sh[30]: + ls -l --full-time /etc/systemd/system/testservice-48.service
# May 07 23:12:20 systemd-testsuite testsuite-48.sh[52]: -rw-r--r-- 1 root root 50 2020-05-07 23:12:20.000000000 +0100 /
# May 07 23:12:20 systemd-testsuite testsuite-48.sh[30]: + stat -f --format=%t /etc/systemd/system/testservice-48.servic
# May 07 23:12:20 systemd-testsuite testsuite-48.sh[53]: ef53
sleep 1.1
cat > /run/systemd/system/testservice-48.service <<EOF
[Service]
ExecStart=/bin/sleep infinity
Type=exec
EOF
systemctl start testservice-48.service
systemctl is-active testservice-48.service
echo OK > /testok
exit 0