xfstests: btrfs/276 - stop all fsstress before exiting

Tests after 276 were failing because the background fsstress
hadn't quit prior to exit, devices couldn't be unmounted, etc.

Just use the same trick as generic/068 does, and use
a tmpfile to control whether the background loop keeps
running.

Also, no need to umount scratch at cleanup time, the scripts
do that for us.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Jan Schmidt list.xfs@jan-o-sch.net
Signed-off-by: Rich Johnston <rjohnston@sgi.com>

tests/btrfs/276

@@ -36,14 +36,8 @@ noise_pid=0
 
 _cleanup()
 {
-	if [ $noise_pid -ne 0 ]; then
-		echo "background noise kill $noise_pid" >>$seqres.full
-		kill $noise_pid
-		noise_pid=0
+	rm $tmp.running
 	wait
-	fi
-	echo "*** unmount"
-	umount $SCRATCH_MNT 2>/dev/null
 	rm -f $tmp.*
 }
 trap "_cleanup; exit \$status" 0 1 2 3 15
@@ -210,7 +204,7 @@ workout()
 
 	if [ $do_bg_noise -ne 0 ]; then
 		# make background noise while backrefs are being walked
-		while /bin/true; do
+		while [ -f "$tmp.running" ]; do
 			echo background fsstress >>$seqres.full
 			run_check $FSSTRESS_PROG -d $SCRATCH_MNT/bgnoise -n 999
 			echo background rm >>$seqres.full
@@ -263,6 +257,8 @@ nfiles=4
 numprocs=1
 do_bg_noise=1
 
+touch $tmp.running
+
 workout $filesize $nfiles $numprocs $snap_name $do_bg_noise
 
 echo "*** done"

tests/btrfs/276.out

@@ -1,4 +1,3 @@
 QA output created by 276
 *** test backref walking
 *** done
-*** unmount