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

core: path: Re-enter waiting if target is deactivating

Browse Source 
Previously, path units would remain in the running state while their
target unit is deactivating. This left a window of time where the target
unit is no longer operational (i.e. it is busy deactivating/cleaning
up/etc) but the path unit would continue to ignore inotify events. In
short: any inotify event that occurs while the target unit deactivates
would be completely lost.

With this commit, the path will go back into a waiting state when the
target unit starts deactivating. This means that any inotify event that
occurs while the target unit deactivates will queue a start job.
This commit is contained in:
Adrian Vovk 2023-12-30 14:06:39 -05:00 committed by Luca Boccassi
parent 1c62c4fe0b
commit 720c618397
4 changed files with 51 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/core/path.c
View File

@ -582,7 +582,7 @@ static void path_enter_waiting(Path *p, bool initial, bool from_trigger_notify)
/* If the triggered unit is already running, so are we */
trigger = UNIT_TRIGGER(UNIT(p));
if (trigger && !UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(trigger))) {
if (trigger && !UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(trigger))) {
path_set_state(p, PATH_RUNNING);
path_unwatch(p);
return;
@ -853,11 +853,11 @@ static void path_trigger_notify_impl(Unit *u, Unit *other, bool on_defer) {
return;
if (p->state == PATH_RUNNING &&
UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other))) {
UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other))) {
if (!on_defer)
log_unit_debug(u, "Got notified about unit deactivation.");
} else if (p->state == PATH_WAITING &&
!UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other))) {
!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other))) {
if (!on_defer)
log_unit_debug(u, "Got notified about unit activation.");
} else

3
test/testsuite-63.units/test63-pr-30768.path Normal file
View File

@ -0,0 +1,3 @@
# SPDX-License-Identifier: LGPL-2.1-or-later
[Path]
PathChanged=/tmp/copyme

5
test/testsuite-63.units/test63-pr-30768.service Normal file
View File

@ -0,0 +1,5 @@
# SPDX-License-Identifier: LGPL-2.1-or-later
[Service]
ExecStart=cp -v /tmp/copyme /tmp/copied
# once cp exits, service goes into deactivating state and then runs ExecStop
ExecStop=flock -e /tmp/noexit true

40
test/units/testsuite-63.sh
View File

@ -80,6 +80,46 @@ output=$(systemctl list-jobs --no-legend)
assert_not_in "test63-issue-24577.service" "$output"
assert_in "test63-issue-24577-dep.service" "$output"
# Test for race condition fixed by https://github.com/systemd/systemd/pull/30768
# Here's the schedule of events that we to happen during this test:
# (This test) (The service)
# .path unit monitors /tmp/copyme for changes
# Take lock on /tmp/noexeit ↓
# Write to /tmp/copyme ↓
# Wait for deactivating Started
# ↓ Copies /tmp/copyme to /tmp/copied
# ↓ Tells manager it's shutting down
# Ensure service did the copy Tries to lock /tmp/noexit and blocks
# Write to /tmp/copyme ↓
#
# Now at this point the test can diverge. If we regress, this second write is
# missed and we'll see:
# ... (second write) ... (blocked)
# Drop lock on /tmp/noexit ↓
# Wait for service to do copy Unblocks and exits
# ↓ (dead)
# ↓
# (timeout)
# Test fails
#
# Otherwise, we'll see:
# ... (second write) ... (blocked)
# Drop lock on /tmp/noexit ↓ and .path unit queues a new start job
# Wait for service to do copy Unblocks and exits
# ↓ Starts again b/c of queued job
# ↓ Copies again
# Test Passes
systemctl start test63-pr-30768.path
exec {lock}<>/tmp/noexit
flock -e $lock
echo test1 > /tmp/copyme
# shellcheck disable=SC2016
timeout 30 bash -c 'until test "$(systemctl show test63-pr-30768.service -P ActiveState)" = deactivating; do sleep .2; done'
diff /tmp/copyme /tmp/copied
echo test2 > /tmp/copyme
exec {lock}<&-
timeout 30 bash -c 'until diff /tmp/copyme /tmp/copied; do sleep .2; done'
systemctl log-level info
touch /testok