ZTS: Fix zpool_expand_001_pos

`zpool_expand_001_pos` was often failing due to not seeing autoexpand
commands in the `zpool history`.  During testing, I found this to be
unreliable (sometimes the "online" wouldn't appear in `zpool history`)
and unnecessary, as we could simply check that the pool increased in
size.

This commit revamps the test to check for the expanded pool size
and corresponding new free space.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #13743

tests/zfs-tests/tests/functional/cli_root/zpool_expand/zpool_expand_001_pos.ksh

@@ -54,6 +54,14 @@
 
 verify_runnable "global"
 
+# We override $org_size and $exp_size from zpool_expand.cfg to make sure we get
+# an expected free space value every time.  Otherwise, if we left it
+# configurable, the free space ratio to pool size ratio would diverge too much
+# much at low $org_size values.
+#
+org_size=$((1024 * 1024 * 1024))
+exp_size=$(($org_size * 2))
+
 function cleanup
 {
 	poolexists $TESTPOOL1 && destroy_pool $TESTPOOL1
@@ -68,6 +76,30 @@ function cleanup
 	unload_scsi_debug
 }
 
+# Wait for the size of a pool to autoexpand to $1 and the total free space to
+# expand to $2 (both values allowing a 10% tolerance).
+#
+# Wait for up to 10 seconds for this to happen (typically takes 1-2 seconds)
+#
+function wait_for_autoexpand
+{
+	typeset exp_new_size=$1
+	typeset exp_new_free=$2
+
+	for i in $(seq 1 10) ; do
+		typeset new_size=$(get_pool_prop size $TESTPOOL1)
+		typeset new_free=$(get_prop avail $TESTPOOL1)
+		# Values need to be within 90% of each other (10% tolerance)
+		if within_percent $new_size $exp_new_size 90 > /dev/null && \
+		    within_percent $new_free $exp_new_free 90 > /dev/null ; then
+			return
+		fi
+		sleep 1
+	done
+	log_fail "$TESTPOOL never expanded to $exp_new_size with $exp_new_free" \
+	    " free space (got $new_size with $new_free free space)"
+}
+
 log_onexit cleanup
 
 log_assert "zpool can be autoexpanded after set autoexpand=on on vdev expansion"
@@ -105,63 +137,38 @@ for type in " " mirror raidz draid:1s; do
 	log_note "Expanding loopback, scsi_debug, and file vdevs"
 	log_must truncate -s $exp_size $FILE_LO
 	log_must losetup -c $DEV1
-	sleep 3
 
 	echo "2" > /sys/bus/pseudo/drivers/scsi_debug/virtual_gb
 	echo "1" > /sys/class/block/$DEV2/device/rescan
 	block_device_wait
-	sleep 3
 
 	log_must truncate -s $exp_size $FILE_RAW
 	log_must zpool online -e $TESTPOOL1 $FILE_RAW
 
-	typeset expand_size=$(get_pool_prop size $TESTPOOL1)
-	typeset zfs_expand_size=$(get_prop avail $TESTPOOL1)
 
-	log_note "$TESTPOOL1 $type has previous size: $prev_size and " \
+	# The expected free space values below were observed at the time of
-	    "expanded size: $expand_size"
+	# this commit.  However, we know ZFS overhead will change over time,
-	# compare available pool size from zfs
+	# and thus we do not do an exact comparison to these values in
-	if [[ $zfs_expand_size -gt $zfs_prev_size ]]; then
+	# wait_for_autoexpand.  Rather, we make sure the free space
-		# check for zpool history for the pool size expansion
+	# is within some small percentage threshold of these values.
-		if [[ $type == " " ]]; then
+	typeset exp_new_size=$(($prev_size * 2))
-			typeset expansion_size=$(($exp_size-$org_size))
+	if [[ "$type" == " " ]] ; then
-			typeset	size_addition=$(zpool history -il $TESTPOOL1 |\
+		exp_new_free=6045892608
-			    grep "pool '$TESTPOOL1' size:" | \
+	elif [[ "$type" == "mirror" ]] ; then
-			    grep "vdev online" | \
+		exp_new_free=1945997312
-			    grep -c "(+${expansion_size}")
+	elif [[ "$type" == "raidz" ]] ; then
-
+		exp_new_free=3977637338
-			if [[ $size_addition -ne 3 ]]; then
+	elif [[ "$type" == "draid:1s" ]] then
-				log_fail "pool $TESTPOOL1 has not expanded, " \
+		exp_new_free=1946000384
-				    "$size_addition/3 vdevs expanded"
-			fi
-		elif [[ $type == "mirror" ]]; then
-			typeset expansion_size=$(($exp_size-$org_size))
-			zpool history -il $TESTPOOL1 | \
-			    grep "pool '$TESTPOOL1' size:" | \
-			    grep "vdev online" | \
-			    grep -q "(+${expansion_size})" ||
-				log_fail "pool $TESTPOOL1 has not expanded"
-		elif [[ $type == "draid:1s" ]]; then
-			typeset expansion_size=$((2*($exp_size-$org_size)))
-			zpool history -il $TESTPOOL1 | \
-			    grep "pool '$TESTPOOL1' size:" | \
-			    grep "vdev online" | \
-			    grep -q "(+${expansion_size})" ||
-					log_fail "pool $TESTPOOL has not expanded"
-		else
-			typeset expansion_size=$((3*($exp_size-$org_size)))
-			zpool history -il $TESTPOOL1 | \
-			    grep "pool '$TESTPOOL1' size:" | \
-			    grep "vdev online" | \
-			    grep -q "(+${expansion_size})" ||
-					log_fail "pool $TESTPOOL has not expanded"
-		fi
-	else
-		log_fail "pool $TESTPOOL1 is not autoexpanded after vdev " \
-		    "expansion.  Previous size: $zfs_prev_size and expanded " \
-		    "size: $zfs_expand_size"
 	fi
 
+	wait_for_autoexpand $exp_new_size $exp_new_free
+
+	expand_size=$(get_pool_prop size $TESTPOOL1)
+
+	log_note "$TESTPOOL1 '$type' grew from $prev_size -> $expand_size with" \
+	    "free space from $zfs_prev_size -> $(get_prop avail $TESTPOOL1)"
+
 	cleanup
 done