diff --git a/SOURCES/19811.patch b/SOURCES/19811.patch
new file mode 100644
index 0000000..fb7c0e2
--- /dev/null
+++ b/SOURCES/19811.patch
@@ -0,0 +1,220 @@
+From 0c81900965a72b29eb76e0737ed899b925ee75b6 Mon Sep 17 00:00:00 2001
+From: Anita Zhang <the.anitazha@gmail.com>
+Date: Tue, 8 Jun 2021 00:04:35 -0700
+Subject: [PATCH 1/2] test: add extended test for triggering mount rate limit
+
+It's hard to trigger the failure to exit the rate limit state in
+isolation as it needs multiple event sources in order to show that it
+gets stuck in the queue. Hence why this is an extended test.
+---
+ test/TEST-60-MOUNT-RATELIMIT/Makefile | 1 +
+ test/TEST-60-MOUNT-RATELIMIT/test.sh | 7 +++
+ test/units/testsuite-60.service | 6 +++
+ test/units/testsuite-60.sh | 73 +++++++++++++++++++++++++++
+ 4 files changed, 87 insertions(+)
+ create mode 120000 test/TEST-60-MOUNT-RATELIMIT/Makefile
+ create mode 100755 test/TEST-60-MOUNT-RATELIMIT/test.sh
+ create mode 100644 test/units/testsuite-60.service
+ create mode 100755 test/units/testsuite-60.sh
+
+diff --git a/test/TEST-60-MOUNT-RATELIMIT/Makefile b/test/TEST-60-MOUNT-RATELIMIT/Makefile
+new file mode 120000
+index 000000000000..e9f93b1104cd
+--- /dev/null
++++ b/test/TEST-60-MOUNT-RATELIMIT/Makefile
+@@ -0,0 +1 @@
++../TEST-01-BASIC/Makefile
+\ No newline at end of file
+diff --git a/test/TEST-60-MOUNT-RATELIMIT/test.sh b/test/TEST-60-MOUNT-RATELIMIT/test.sh
+new file mode 100755
+index 000000000000..f9eb11ccb441
+--- /dev/null
++++ b/test/TEST-60-MOUNT-RATELIMIT/test.sh
+@@ -0,0 +1,7 @@
++#!/usr/bin/env bash
++set -e
++TEST_DESCRIPTION="Test that mount/unmount storms can enter/exit rate limit state and will not leak units"
++
++. $TEST_BASE_DIR/test-functions
++
++do_test "$@"
+diff --git a/test/units/testsuite-60.service b/test/units/testsuite-60.service
+new file mode 100644
+index 000000000000..3715c4f341c8
+--- /dev/null
++++ b/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
+diff --git a/test/units/testsuite-60.sh b/test/units/testsuite-60.sh
+new file mode 100755
+index 000000000000..815875466762
+--- /dev/null
++++ b/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
+
+From 81107b8419c39f726fd2805517a5b9faab204e59 Mon Sep 17 00:00:00 2001
+From: Lennart Poettering <lennart@poettering.net>
+Date: Tue, 8 Jun 2021 00:07:51 -0700
+Subject: [PATCH 2/2] sd-event: change ordering of pending/ratelimited events
+
+Instead of ordering non-pending before pending we should order
+"non-pending OR ratelimited" before "pending AND not-ratelimited".
+This fixes a bug where ratelimited events were ordered at the end of the
+priority queue and could be stuck there for an indeterminate amount of
+time.
+---
+ src/libsystemd/sd-event/sd-event.c | 45 ++++++++++++++----------------
+ 1 file changed, 21 insertions(+), 24 deletions(-)
+
+diff --git a/src/libsystemd/sd-event/sd-event.c b/src/libsystemd/sd-event/sd-event.c
+index 611af45293ac..489878a3e967 100644
+--- a/src/libsystemd/sd-event/sd-event.c
++++ b/src/libsystemd/sd-event/sd-event.c
+@@ -237,25 +237,6 @@ static usec_t time_event_source_next(const sd_event_source *s) {
+ return USEC_INFINITY;
+ }
+
+-static int earliest_time_prioq_compare(const void *a, const void *b) {
+- const sd_event_source *x = a, *y = b;
+-
+- /* Enabled ones first */
+- if (x->enabled != SD_EVENT_OFF && y->enabled == SD_EVENT_OFF)
+- return -1;
+- if (x->enabled == SD_EVENT_OFF && y->enabled != SD_EVENT_OFF)
+- return 1;
+-
+- /* Move the pending ones to the end */
+- if (!x->pending && y->pending)
+- return -1;
+- if (x->pending && !y->pending)
+- return 1;
+-
+- /* Order by time */
+- return CMP(time_event_source_next(x), time_event_source_next(y));
+-}
+-
+ static usec_t time_event_source_latest(const sd_event_source *s) {
+ assert(s);
+
+@@ -274,7 +255,15 @@ static usec_t time_event_source_latest(const sd_event_source *s) {
+ return USEC_INFINITY;
+ }
+
+-static int latest_time_prioq_compare(const void *a, const void *b) {
++static bool event_source_timer_candidate(const sd_event_source *s) {
++ assert(s);
++
++ /* Returns true for event sources that either are not pending yet (i.e. where it's worth to mark them pending)
++ * or which are currently ratelimited (i.e. where it's worth leaving the ratelimited state) */
++ return !s->pending || s->ratelimited;
++}
++
++static int time_prioq_compare(const void *a, const void *b, usec_t (*time_func)(const sd_event_source *s)) {
+ const sd_event_source *x = a, *y = b;
+
+ /* Enabled ones first */
+@@ -283,14 +272,22 @@ static int latest_time_prioq_compare(const void *a, const void *b) {
+ if (x->enabled == SD_EVENT_OFF && y->enabled != SD_EVENT_OFF)
+ return 1;
+
+- /* Move the pending ones to the end */
+- if (!x->pending && y->pending)
++ /* Order "non-pending OR ratelimited" before "pending AND not-ratelimited" */
++ if (event_source_timer_candidate(x) && !event_source_timer_candidate(y))
+ return -1;
+- if (x->pending && !y->pending)
++ if (!event_source_timer_candidate(x) && event_source_timer_candidate(y))
+ return 1;
+
+ /* Order by time */
+- return CMP(time_event_source_latest(x), time_event_source_latest(y));
++ return CMP(time_func(x), time_func(y));
++}
++
++static int earliest_time_prioq_compare(const void *a, const void *b) {
++ return time_prioq_compare(a, b, time_event_source_next);
++}
++
++static int latest_time_prioq_compare(const void *a, const void *b) {
++ return time_prioq_compare(a, b, time_event_source_latest);
+ }
+
+ static int exit_prioq_compare(const void *a, const void *b) {
diff --git a/SPECS/systemd.spec b/SPECS/systemd.spec
index eb61505..3d89b31 100644
--- a/SPECS/systemd.spec
+++ b/SPECS/systemd.spec
@@ -26,7 +26,7 @@
Name: systemd
Url: https://www.freedesktop.org/wiki/Software/systemd
Version: 248.2
-Release: 1.3%{?dist}
+Release: 1.4%{?dist}
# For a breakdown of the licensing, see README
License: LGPLv2+ and MIT and GPLv2+
Summary: System and Service Manager
@@ -94,6 +94,7 @@ Patch0102: 17495-rebased.patch
# PR 18621: Quiet "proc: Bad value for 'hidepid'" messages
Patch0101: https://github.com/systemd/systemd/pull/18621.patch
%endif
+Patch0103: https://github.com/systemd/systemd/pull/19811.patch
# Downstream-only patches (0500–9999)
@@ -959,6 +960,9 @@ fi
%endif
%changelog
+* Thu Jun 10 2021 Anita Zhang <anitazha@fb.com> - 248.2-1.4
+- Backport PR #19811 to fix issues with mount sd-event rate limiting
+
* Wed May 19 2021 Davide Cavalca <dcavalca@centosproject.org> - 248.2-1.3
- Add BuildRequires for python-jinja2 in preparation for 249 (see PR#19630)