Checksum errors may not be counted

Fix regression seen in issue #11545 where checksum errors 
where not being counted or showing up in a zpool event.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Don Brady <don.brady@delphix.com>
Closes #11609

tests/zfs-tests/tests/functional/cli_root/zpool_events/Makefile.am

@@ -11,7 +11,8 @@ dist_pkgdata_SCRIPTS = \
 	zpool_events_follow.ksh \
 	zpool_events_poolname.ksh \
 	zpool_events_errors.ksh \
-	zpool_events_duplicates.ksh
+	zpool_events_duplicates.ksh \
+	zpool_events_clear_retained.ksh
 
 dist_pkgdata_DATA = \
 	zpool_events.cfg \

tests/zfs-tests/tests/functional/cli_root/zpool_events/zpool_events_clear_retained.ksh

@@ -0,0 +1,135 @@
+#!/bin/ksh -p
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright (c) 2018 by Lawrence Livermore National Security, LLC.
+# Copyright (c) 2021 by Delphix. All rights reserved.
+#
+
+# DESCRIPTION:
+#	Verify that new errors after a pool scrub are considered a duplicate
+#
+# STRATEGY:
+#	1. Create a raidz pool with a file
+#	2. Inject garbage into one of the vdevs
+#	3. Scrub the pool
+#	4. Observe the checksum error counts
+#	5. Repeat inject and pool scrub
+#	6. Verify that second pass also produces similar errors (i.e. not
+#	   treated as a duplicate)
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+verify_runnable "both"
+
+MOUNTDIR=$TEST_BASE_DIR/mount
+FILEPATH=$MOUNTDIR/target
+VDEV1=$TEST_BASE_DIR/vfile1
+VDEV2=$TEST_BASE_DIR/vfile2
+VDEV3=$TEST_BASE_DIR/vfile3
+SUPPLY=$TEST_BASE_DIR/supply
+POOL=test_pool
+FILESIZE="15M"
+DAMAGEBLKS=10
+
+OLD_LEN_MAX=$(get_tunable ZEVENT_LEN_MAX)
+RETAIN_MAX=$(get_tunable ZEVENT_RETAIN_MAX)
+OLD_CHECKSUMS=$(get_tunable CHECKSUM_EVENTS_PER_SECOND)
+
+EREPORTS="$STF_SUITE/tests/functional/cli_root/zpool_events/ereports"
+
+function cleanup
+{
+	log_must set_tunable64 CHECKSUM_EVENTS_PER_SECOND $OLD_CHECKSUMS
+	log_must set_tunable64 ZEVENT_LEN_MAX $OLD_LEN_MAX
+
+	zpool events -c
+	if poolexists $POOL ; then
+		zpool export $POOL
+	fi
+	log_must rm -f $VDEV1 $VDEV2 $VDEV3
+}
+
+function damage_and_repair
+{
+	log_must zpool clear $POOL $VDEV1
+	log_must zpool events -c
+
+	log_note injecting damage to $VDEV1
+	log_must dd conv=notrunc if=$SUPPLY of=$VDEV1 bs=1M seek=4 count=$DAMAGEBLKS
+	log_must zpool scrub $POOL
+	log_must zpool wait -t scrub $POOL
+	log_note "pass $1 observed $($EREPORTS | grep -c checksum) checksum ereports"
+
+	repaired=$(zpool status $POOL | grep "scan: scrub repaired" | awk '{print $4}')
+	if [ "$repaired" == "0B" ]; then
+		log_fail "INVALID TEST -- expected scrub to repair some blocks"
+	else
+		log_note "$repaired repaired during scrub"
+	fi
+}
+
+function checksum_error_count
+{
+	zpool status -p $POOL | grep $VDEV1 | awk '{print $5}'
+}
+
+assertion="Damage to recently repaired blocks should be reported/counted"
+log_assert "$assertion"
+log_note "zevent retain max setting: $RETAIN_MAX"
+
+log_onexit cleanup
+
+# Set our threshold high to avoid dropping events.
+set_tunable64 ZEVENT_LEN_MAX 20000
+set_tunable64 CHECKSUM_EVENTS_PER_SECOND 20000
+
+# Initialize resources for the test
+log_must truncate -s $MINVDEVSIZE $VDEV1 $VDEV2 $VDEV3
+log_must dd if=/dev/urandom of=$SUPPLY bs=1M count=$DAMAGEBLKS
+log_must mkdir -p $MOUNTDIR
+log_must zpool create -f -m $MOUNTDIR -o failmode=continue $POOL raidz $VDEV1 $VDEV2 $VDEV3
+log_must zfs set compression=off recordsize=16k $POOL
+# create a file full of zeros
+log_must mkfile -v $FILESIZE $FILEPATH
+log_must zpool sync $POOL
+
+# run once and observe the checksum errors
+damage_and_repair 1
+errcnt=$(checksum_error_count)
+log_note "$errcnt errors observed"
+# set expectaton of at least 75% of what we observed in first pass
+(( expected = (errcnt * 75) / 100 ))
+
+# run again and we should observe new checksum errors
+damage_and_repair 2
+errcnt=$(checksum_error_count)
+
+log_must zpool destroy $POOL
+
+if (( errcnt < expected )); then
+	log_fail "FAILED -- expecting at least $expected checksum errors but only observed $errcnt"
+else
+	log_note observed $errcnt new checksum errors after a scrub
+	log_pass "$assertion"
+fi
+

tests/zfs-tests/tests/functional/cli_root/zpool_events/zpool_events_duplicates.ksh

@@ -114,21 +114,10 @@ function do_dup_test
 	if [ "$RW" == "write" ] ; then
 		log_must mkfile $FILESIZE $FILEPATH
 		log_must zpool sync $POOL
-	else
-		# scrub twice to generate some duplicates
-		log_must zpool scrub $POOL
-		log_must zpool wait -t scrub $POOL
-		log_must zpool scrub $POOL
-		log_must zpool wait -t scrub $POOL
 	fi
 
 	log_must zinject -c all
 
-	# Wait for the pool to settle down and finish resilvering (if
-	# necessary).  We want the errors to stop incrementing before we
-	# check for duplicates.
-	zpool wait -t resilver $POOL
-
 	ereports="$($EREPORTS | sort)"
 	actual=$(echo "$ereports" | wc -l)
 	unique=$(echo "$ereports" | uniq | wc -l)