diff --git a/common/xfs b/common/xfs
index 19ccee03..4274eee7 100644
--- a/common/xfs
+++ b/common/xfs
@@ -1008,3 +1008,19 @@ _xfs_timestamp_range()
 		$dbprog -f -c 'timelimit --compact' | awk '{printf("%s %s", $1, $2);}'
 	fi
 }
+
+_require_xfs_mkfs_bigtime()
+{
+	_scratch_mkfs_xfs_supported -m bigtime=1 >/dev/null 2>&1 \
+	   || _notrun "mkfs.xfs doesn't have bigtime feature"
+}
+
+_require_xfs_scratch_bigtime()
+{
+	_require_scratch
+
+	_scratch_mkfs -m bigtime=1 > /dev/null
+	_try_scratch_mount || \
+		_notrun "bigtime not supported by scratch filesystem type: $FSTYP"
+	_scratch_unmount
+}
diff --git a/tests/xfs/908 b/tests/xfs/908
new file mode 100755
index 00000000..e368d66c
--- /dev/null
+++ b/tests/xfs/908
@@ -0,0 +1,87 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2020, Oracle and/or its affiliates.  All Rights Reserved.
+#
+# FS QA Test No. 908
+#
+# Check that we can upgrade a filesystem to support bigtime and that inode
+# timestamps work properly after the upgrade.
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1    # failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# We have very specific formatting parameters, so don't let things get complex
+# with realtime devices and external logs.
+unset USE_EXTERNAL
+
+# real QA test starts here
+_supported_fs xfs
+_require_xfs_mkfs_crc
+_require_xfs_mkfs_bigtime
+_require_xfs_scratch_bigtime
+
+date --date='Jan 1 00:00:00 UTC 2040' > /dev/null 2>&1 || \
+	_notrun "Userspace does not support dates past 2038."
+
+rm -f $seqres.full
+
+# Format V5 filesystem without bigtime support and populate it
+_scratch_mkfs -m crc=1,bigtime=0 > $seqres.full
+_scratch_xfs_db -c 'version' -c 'sb 0' -c 'p' >> $seqres.full
+_scratch_mount >> $seqres.full
+
+touch -d 'Jan 9 19:19:19 UTC 1999' $SCRATCH_MNT/a
+touch -d 'Jan 9 19:19:19 UTC 1999' $SCRATCH_MNT/b
+ls -la $SCRATCH_MNT/* >> $seqres.full
+
+echo before upgrade:
+TZ=UTC stat -c '%Y' $SCRATCH_MNT/a
+TZ=UTC stat -c '%Y' $SCRATCH_MNT/b
+
+_scratch_unmount
+_check_scratch_fs
+
+# Now upgrade to bigtime support
+_scratch_xfs_admin -O bigtime >> $seqres.full
+_check_scratch_fs
+_scratch_xfs_db -c 'version' -c 'sb 0' -c 'p' >> $seqres.full
+
+# Mount again, look at our files
+_scratch_mount >> $seqres.full
+ls -la $SCRATCH_MNT/* >> $seqres.full
+
+# Modify one of the timestamps to stretch beyond 2038
+touch -d 'Feb 22 22:22:22 UTC 2222' $SCRATCH_MNT/b
+
+echo after upgrade:
+TZ=UTC stat -c '%Y' $SCRATCH_MNT/a
+TZ=UTC stat -c '%Y' $SCRATCH_MNT/b
+
+_scratch_cycle_mount
+
+# Did the timestamp survive the remount?
+ls -la $SCRATCH_MNT/* >> $seqres.full
+
+echo after upgrade and remount:
+TZ=UTC stat -c '%Y' $SCRATCH_MNT/a
+TZ=UTC stat -c '%Y' $SCRATCH_MNT/b
+
+# success, all done
+status=0
+exit
diff --git a/tests/xfs/908.out b/tests/xfs/908.out
new file mode 100644
index 00000000..f0f412be
--- /dev/null
+++ b/tests/xfs/908.out
@@ -0,0 +1,10 @@
+QA output created by 908
+before upgrade:
+915909559
+915909559
+after upgrade:
+915909559
+7956915742
+after upgrade and remount:
+915909559
+7956915742
diff --git a/tests/xfs/909 b/tests/xfs/909
new file mode 100755
index 00000000..7010eb9e
--- /dev/null
+++ b/tests/xfs/909
@@ -0,0 +1,153 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2020, Oracle and/or its affiliates.  All Rights Reserved.
+#
+# FS QA Test No. 909
+#
+# Check that we can upgrade a filesystem to support bigtime and that quota
+# timers work properly after the upgrade.
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1    # failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/quota
+
+# We have very specific formatting parameters, so don't let things get complex
+# with realtime devices and external logs.
+unset USE_EXTERNAL
+
+# real QA test starts here
+_supported_fs xfs
+_require_quota
+_require_xfs_mkfs_crc
+_require_xfs_mkfs_bigtime
+_require_xfs_scratch_bigtime
+
+date --date='Jan 1 00:00:00 UTC 2040' > /dev/null 2>&1 || \
+	_notrun "Userspace does not support dates past 2038."
+
+rm -f $seqres.full
+
+# Format V5 filesystem without bigtime support and populate it
+_scratch_mkfs -m crc=1,bigtime=0 > $seqres.full
+_qmount_option "usrquota"
+_scratch_xfs_db -c 'version' -c 'sb 0' -c 'p' >> $seqres.full
+_scratch_mount >> $seqres.full
+
+# Force the block counters for uid 1 and 2 above zero
+_pwrite_byte 0x61 0 64k $SCRATCH_MNT/a >> $seqres.full
+_pwrite_byte 0x61 0 64k $SCRATCH_MNT/b >> $seqres.full
+sync
+chown 1 $SCRATCH_MNT/a
+chown 2 $SCRATCH_MNT/b
+
+# Set quota limits on uid 1 before upgrading
+$XFS_QUOTA_PROG -x -c 'limit -u bsoft=12k bhard=1m 1' $SCRATCH_MNT
+
+# Make sure the grace period is at /some/ point in the future.  We have to
+# use bc because not all bashes can handle integer comparisons with 64-bit
+# numbers.
+repquota -upn $SCRATCH_MNT > $tmp.repquota
+cat $tmp.repquota >> $seqres.full
+grace="$(cat $tmp.repquota | grep '^#1' | awk '{print $6}')"
+now="$(date +%s)"
+res="$(echo "${grace} > ${now}" | $BC_PROG)"
+test $res -eq 1 || echo "Expected timer expiry (${grace}) to be after now (${now})."
+
+_scratch_unmount
+
+# Now upgrade to bigtime support
+_scratch_xfs_admin -O bigtime >> $seqres.full
+_check_scratch_fs
+_scratch_xfs_db -c 'version' -c 'sb 0' -c 'p' >> $seqres.full
+
+# Mount again, see if our quota timer survived
+_scratch_mount
+
+# Set a very generous grace period and quota limits on uid 2 after upgrading
+$XFS_QUOTA_PROG -x -c 'timer -u -b -d 2147483647' $SCRATCH_MNT
+$XFS_QUOTA_PROG -x -c 'limit -u bsoft=10000 bhard=150000 2' $SCRATCH_MNT
+
+# Query the grace periods to see if they got set properly after the upgrade.
+repquota -upn $SCRATCH_MNT > $tmp.repquota
+cat $tmp.repquota >> $seqres.full
+grace1="$(repquota -upn $SCRATCH_MNT | grep '^#1' | awk '{print $6}')"
+grace2="$(repquota -upn $SCRATCH_MNT | grep '^#2' | awk '{print $6}')"
+now="$(date +%s)"
+
+# Make sure that uid 1's expiration is in the future...
+res1="$(echo "${grace} > ${now}" | $BC_PROG)"
+test "${res1}" -eq 1 || echo "Expected uid 1 expiry (${grace1}) to be after now (${now})."
+
+# ...and that uid 2's expiration is after uid 1's...
+res2="$(echo "${grace2} > ${grace1}" | $BC_PROG)"
+test "${res2}" -eq 1 || echo "Expected uid 2 expiry (${grace2}) to be after uid 1 (${grace1})."
+
+# ...and that uid 2's expiration is after 2038 if right now is far enough
+# past 1970 that our generous grace period would provide for that.
+res3="$(echo "(${now} < 100) || (${grace2} > 2147483648)" | $BC_PROG)"
+test "${res3}" -eq 1 || echo "Expected uid 2 expiry (${grace2}) to be after 2038."
+
+_scratch_cycle_mount
+
+# Query the grace periods to see if they survived a remount.
+repquota -upn $SCRATCH_MNT > $tmp.repquota
+cat $tmp.repquota >> $seqres.full
+grace1="$(repquota -upn $SCRATCH_MNT | grep '^#1' | awk '{print $6}')"
+grace2="$(repquota -upn $SCRATCH_MNT | grep '^#2' | awk '{print $6}')"
+now="$(date +%s)"
+
+# Make sure that uid 1's expiration is in the future...
+res1="$(echo "${grace} > ${now}" | $BC_PROG)"
+test "${res1}" -eq 1 || echo "Expected uid 1 expiry (${grace1}) to be after now (${now})."
+
+# ...and that uid 2's expiration is after uid 1's...
+res2="$(echo "${grace2} > ${grace1}" | $BC_PROG)"
+test "${res2}" -eq 1 || echo "Expected uid 2 expiry (${grace2}) to be after uid 1 (${grace1})."
+
+# ...and that uid 2's expiration is after 2038 if right now is far enough
+# past 1970 that our generous grace period would provide for that.
+res3="$(echo "(${now} < 100) || (${grace2} > 2147483648)" | $BC_PROG)"
+test "${res3}" -eq 1 || echo "Expected uid 2 expiry (${grace2}) to be after 2038."
+
+# Now try setting uid 2's expiration to Feb 22 22:22:22 UTC 2222
+new_expiry=$(date -d 'Feb 22 22:22:22 UTC 2222' +%s)
+now=$(date +%s)
+test $now -ge $new_expiry && \
+	echo "Now is after February 2222?  Expect problems."
+expiry_delta=$((new_expiry - now))
+
+echo "setting expiration to $new_expiry - $now = $expiry_delta" >> $seqres.full
+$XFS_QUOTA_PROG -x -c "timer -u $expiry_delta 2" -c 'report' $SCRATCH_MNT >> $seqres.full
+
+# Did we get an expiration within 5s of the target range?
+grace2="$(repquota -upn $SCRATCH_MNT | grep '^#2' | awk '{print $6}')"
+echo "grace2 is $grace2" >> $seqres.full
+_within_tolerance "grace2 expiry" $grace2 $new_expiry 5 -v
+
+_scratch_cycle_mount
+
+# ...and is it still within 5s after a remount?
+grace2="$(repquota -upn $SCRATCH_MNT | grep '^#2' | awk '{print $6}')"
+echo "grace2 is $grace2" >> $seqres.full
+_within_tolerance "grace2 expiry after remount" $grace2 $new_expiry 5 -v
+
+# success, all done
+echo Silence is golden.
+status=0
+exit
diff --git a/tests/xfs/909.out b/tests/xfs/909.out
new file mode 100644
index 00000000..948502b7
--- /dev/null
+++ b/tests/xfs/909.out
@@ -0,0 +1,4 @@
+QA output created by 909
+grace2 expiry is in range
+grace2 expiry after remount is in range
+Silence is golden.
diff --git a/tests/xfs/group b/tests/xfs/group
index f61d46a1..ab98a706 100644
--- a/tests/xfs/group
+++ b/tests/xfs/group
@@ -524,6 +524,8 @@
 760 auto quick rw collapse punch insert zero prealloc
 761 auto quick realtime
 763 auto quick rw realtime
+908 auto quick bigtime
+909 auto quick bigtime quota
 910 auto quick inobtcount
 911 auto quick bigtime
 915 auto quick quota
