Merge pull request #19811 from anitazha/revert_mount_rl

sd-event: fix failure to exit rate limiting state

test/units/testsuite-60.service

@@ -0,0 +1,6 @@
+[Unit]
+Description=TEST-60-MOUNT-RATELIMIT
+
+[Service]
+Type=oneshot
+ExecStart=/usr/lib/systemd/tests/testdata/units/%N.sh

test/units/testsuite-60.sh

@@ -0,0 +1,73 @@
+#!/usr/bin/env bash
+set -eux
+set -o pipefail
+
+systemd-analyze log-level debug
+systemd-analyze log-target journal
+
+NUM_DIRS=20
+
+# mount/unmount enough times to trigger the /proc/self/mountinfo parsing rate limiting
+
+for ((i = 0; i < NUM_DIRS; i++)); do
+    mkdir "/tmp/meow${i}"
+done
+
+for ((i = 0; i < NUM_DIRS; i++)); do
+    mount -t tmpfs tmpfs "/tmp/meow${i}"
+done
+
+systemctl daemon-reload
+systemctl list-units -t mount tmp-meow* | grep -q tmp-meow
+
+for ((i = 0; i < NUM_DIRS; i++)); do
+    umount "/tmp/meow${i}"
+done
+
+# figure out if we have entered the rate limit state
+
+exited_rl=0
+timeout="$(date -ud "2 minutes" +%s)"
+while [[ $(date -u +%s) -le ${timeout} ]]; do
+    if journalctl -u init.scope | grep -q "(mount-monitor-dispatch) entered rate limit"; then
+        entered_rl=1
+        break
+    fi
+    sleep 5
+done
+
+# if the infra is slow we might not enter the rate limit state; in that case skip the exit check
+
+if [ "${entered_rl}" = "1" ]; then
+    exited_rl=0
+    timeout="$(date -ud "2 minutes" +%s)"
+    while [[ $(date -u +%s) -le ${timeout} ]]; do
+        if journalctl -u init.scope | grep -q "(mount-monitor-dispatch) left rate limit"; then
+            exited_rl=1
+            break
+        fi
+        sleep 5
+    done
+
+    if [ "${exited_rl}" = "0" ]; then
+        exit 24
+    fi
+fi
+
+# give some time for units to settle so we don't race between exiting the rate limit state and cleaning up the units
+
+sleep 60
+systemctl daemon-reload
+sleep 60
+
+# verify that the mount units are always cleaned up at the end
+
+if systemctl list-units -t mount tmp-meow* | grep -q tmp-meow; then
+    exit 42
+fi
+
+systemd-analyze log-level info
+
+echo OK >/testok
+
+exit 0