btrfs/022: fix failed case with qgroup limit test

To have noexceed test, we should clear data before and then retry.
However, when we are near to quota limit, we may fail to truncate/remove
data before, so we restart everthing here.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

tests/btrfs/022

@@ -94,8 +94,8 @@ _rescan_test()
 		_fail "exclusive values don't match after rescan"
 }
 
-#basic limit testing
-_limit_test()
+#basic exceed limit testing
+_limit_test_exceed()
 {
 	run_check $BTRFS_UTIL_PROG subvol create $SCRATCH_MNT/a
 	run_check $BTRFS_UTIL_PROG quota enable $SCRATCH_MNT
@@ -104,6 +104,15 @@ _limit_test()
 	dd if=/dev/urandom of=$SCRATCH_MNT/a/file bs=10M count=1 >> \
 		$seqres.full 2>&1
 	[ $? -ne 0 ] || _fail "quota should have limited us"
+}
+
+#basic noexceed limit testing
+_limit_test_noexceed()
+{
+	run_check $BTRFS_UTIL_PROG subvol create $SCRATCH_MNT/a
+	run_check $BTRFS_UTIL_PROG quota enable $SCRATCH_MNT
+	subvolid=$(_btrfs_get_subvolid $SCRATCH_MNT a)
+	run_check $BTRFS_UTIL_PROG qgroup limit 5M 0/$subvolid $SCRATCH_MNT
 	dd if=/dev/urandom of=$SCRATCH_MNT/a/file bs=4M count=1 >> \
 		$seqres.full 2>&1
 	[ $? -eq 0 ] || _fail "should have been allowed to write"
@@ -121,7 +130,12 @@ _scratch_unmount
 
 _scratch_mkfs > /dev/null 2>&1
 _scratch_mount
-_limit_test
+_limit_test_exceed
+_scratch_unmount
+
+_scratch_mkfs > /dev/null 2>&1
+_scratch_mount
+_limit_test_noexceed
 
 # success, all done
 echo "Silence is golden"