qa: add rbd/diff_continuous.sh stress test

Stress test that does io on an image while we are mirroring a diff from
earlier snaps to a second copy.  At the end, verify that all snaps have
matching content.

Signed-off-by: Sage Weil <sage@inktank.com>

diff --git a/qa/workunits/rbd/diff_continuous.sh b/qa/workunits/rbd/diff_continuous.sh
new file mode 100755 (executable)
index 0000000..b7f4dc0
--- /dev/null
+++ b/qa/workunits/rbd/diff_continuous.sh
@@ -0,0 +1,51 @@
+#!/bin/bash -ex
+
+max=30
+size=1500
+
+iosize=16384
+iototal=16384000
+iothreads=16
+
+src=`uuidgen`"-src";
+dst=`uuidgen`"-dst";
+
+function cleanup() {
+    rbd snap purge $src || :
+    rbd rm $src || :
+    rbd snap purge $dst || :
+    rbd rm $dst || :
+}
+trap cleanup EXIT
+
+rbd create $src --size $size
+rbd create $dst --size $size
+
+# mirror for a while
+
+rbd snap create $src --snap=snap0
+rbd bench-write $src --io-size $iosize --io-threads $iothreads --io-total $iototal --io-pattern rand 
+lastsnap=snap0
+for s in `seq 1 $max`; do
+    rbd snap create $src --snap=snap$s
+    rbd export-diff $src@snap$s - --from-snap $lastsnap | rbd import-diff - $dst  &
+    rbd bench-write $src --io-size $iosize --io-threads $iothreads --io-total $iototal --io-pattern rand  &
+    wait
+    lastsnap=snap$s
+done
+
+# validate
+for s in `seq 1 $max`; do
+    ssum=`rbd export $src@snap$s - | md5sum`
+    dsum=`rbd export $dst@snap$s - | md5sum`
+    if [ "$ssum" != "$dsum" ]; then
+       echo different sum at snap$s
+       exit 1
+    fi
+done
+
+cleanup
+trap "" EXIT
+
+echo OK
+