6249 async_destroy_001_pos fails because it doesn't see 'freeing' pro…

…p populated

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

usr/src/test/zfs-tests/tests/functional/features/async_destroy/async_destroy_001_pos.ksh

@@ -21,7 +21,7 @@
 #
 
 #
-# Copyright (c) 2013 by Delphix. All rights reserved.
+# Copyright (c) 2013, 2014 by Delphix. All rights reserved.
 #
 
 . $STF_SUITE/include/libtest.shlib
@@ -56,29 +56,32 @@ log_assert "async_destroy can suspend and resume traversal"
 
 log_must $ZFS create -o recordsize=512 -o compression=off $TEST_FS
 
-#
 # Fill with 2G
-#
 log_must $DD bs=1024k count=2048 if=/dev/zero of=/$TEST_FS/file
 
 log_must $ZFS destroy $TEST_FS
 
+#
+# We monitor the freeing property, to verify we can see blocks being
+# freed while the suspend/resume code is exerciesd.
+#
+t0=$SECONDS
 count=0
-while [[ "0" != "$($ZPOOL list -Ho freeing $TESTPOOL)" ]]; do
-	count=$((count + 1))
-	sleep 1
+while [[ $((SECONDS - t0)) -lt 10 ]]; do
+	[[ "0" != "$($ZPOOL list -Ho freeing $TESTPOOL)" ]] && ((count++))
+	[[ $count -gt 1 ]] && break
+	$SLEEP 1
 done
 
-#
-# We assert that the data took a few seconds to free to make sure that
-# we actually exercised the suspend/resume code. The destroy should
-# actually take much longer than this, so false positives are not likely.
-#
-log_must test $count -gt 5
+[[ $count -eq 0 ]] && log_fail "Freeing property remained empty"
+
+# Wait for everything to be freed.
+while [[ "0" != "$($ZPOOL list -Ho freeing $TESTPOOL)" ]]; do
+	[[ $((SECONDS - t0)) -gt 180 ]] && \
+	    log_fail "Timed out waiting for freeing to drop to zero"
+done
 
-#
 # Check for leaked blocks.
-#
 log_must $ZDB -b $TESTPOOL
 
 log_pass "async_destroy can suspend and resume traversal"