test-bdrv-drain: Test draining job source child and parent

For the block job drain test, don't only test draining the source and
the target node, but create a backing chain for the source
(source_backing <- source <- source_overlay) and test draining each of
the nodes in it.

When using iothreads, the source node (and therefore the job) is in a
different AioContext than the drain, which happens from the main
thread. This way, the main thread waits in AIO_WAIT_WHILE() for the
iothread to make process and aio_wait_kick() is required to notify it.
The test validates that calling bdrv_wakeup() for a child or a parent
node will actually notify AIO_WAIT_WHILE() instead of letting it hang.

Increase the sleep time a bit (to 1 ms) because the test case is racy
and with the shorter sleep, it didn't reproduce the bug it is supposed
to test for me under 'rr record -n'.

This was because bdrv_drain_invoke_entry() (in the main thread) was only
called after the job had already reached the pause point, so we got a
bdrv_dec_in_flight() from the main thread and the additional
aio_wait_kick() when the job becomes idle (that we really wanted to test
here) wasn't even necessary any more to make progress.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
master
Kevin Wolf 2018-09-20 17:39:13 +02:00
parent cfe29d8294
commit d8b3afd597
1 changed files with 69 additions and 8 deletions

View File

@ -786,6 +786,7 @@ typedef struct TestBlockJob {
BlockJob common;
int run_ret;
int prepare_ret;
bool running;
bool should_complete;
} TestBlockJob;
@ -818,12 +819,17 @@ static int coroutine_fn test_job_run(Job *job, Error **errp)
{
TestBlockJob *s = container_of(job, TestBlockJob, common.job);
/* We are running the actual job code past the pause point in
* job_co_entry(). */
s->running = true;
job_transition_to_ready(&s->common.job);
while (!s->should_complete) {
/* Avoid job_sleep_ns() because it marks the job as !busy. We want to
* emulate some actual activity (probably some I/O) here so that drain
* has to wait for this activity to stop. */
qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 100000);
qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 1000000);
job_pause_point(&s->common.job);
}
@ -856,11 +862,19 @@ enum test_job_result {
TEST_JOB_FAIL_PREPARE,
};
static void test_blockjob_common(enum drain_type drain_type, bool use_iothread,
enum test_job_result result)
enum test_job_drain_node {
TEST_JOB_DRAIN_SRC,
TEST_JOB_DRAIN_SRC_CHILD,
TEST_JOB_DRAIN_SRC_PARENT,
};
static void test_blockjob_common_drain_node(enum drain_type drain_type,
bool use_iothread,
enum test_job_result result,
enum test_job_drain_node drain_node)
{
BlockBackend *blk_src, *blk_target;
BlockDriverState *src, *target;
BlockDriverState *src, *src_backing, *src_overlay, *target, *drain_bs;
BlockJob *job;
TestBlockJob *tjob;
IOThread *iothread = NULL;
@ -869,8 +883,32 @@ static void test_blockjob_common(enum drain_type drain_type, bool use_iothread,
src = bdrv_new_open_driver(&bdrv_test, "source", BDRV_O_RDWR,
&error_abort);
src_backing = bdrv_new_open_driver(&bdrv_test, "source-backing",
BDRV_O_RDWR, &error_abort);
src_overlay = bdrv_new_open_driver(&bdrv_test, "source-overlay",
BDRV_O_RDWR, &error_abort);
bdrv_set_backing_hd(src_overlay, src, &error_abort);
bdrv_unref(src);
bdrv_set_backing_hd(src, src_backing, &error_abort);
bdrv_unref(src_backing);
blk_src = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
blk_insert_bs(blk_src, src, &error_abort);
blk_insert_bs(blk_src, src_overlay, &error_abort);
switch (drain_node) {
case TEST_JOB_DRAIN_SRC:
drain_bs = src;
break;
case TEST_JOB_DRAIN_SRC_CHILD:
drain_bs = src_backing;
break;
case TEST_JOB_DRAIN_SRC_PARENT:
drain_bs = src_overlay;
break;
default:
g_assert_not_reached();
}
if (use_iothread) {
iothread = iothread_new();
@ -906,11 +944,21 @@ static void test_blockjob_common(enum drain_type drain_type, bool use_iothread,
job_start(&job->job);
aio_context_release(ctx);
if (use_iothread) {
/* job_co_entry() is run in the I/O thread, wait for the actual job
* code to start (we don't want to catch the job in the pause point in
* job_co_entry(). */
while (!tjob->running) {
aio_poll(qemu_get_aio_context(), false);
}
}
g_assert_cmpint(job->job.pause_count, ==, 0);
g_assert_false(job->job.paused);
g_assert_true(tjob->running);
g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */
do_drain_begin_unlocked(drain_type, src);
do_drain_begin_unlocked(drain_type, drain_bs);
if (drain_type == BDRV_DRAIN_ALL) {
/* bdrv_drain_all() drains both src and target */
@ -921,7 +969,7 @@ static void test_blockjob_common(enum drain_type drain_type, bool use_iothread,
g_assert_true(job->job.paused);
g_assert_false(job->job.busy); /* The job is paused */
do_drain_end_unlocked(drain_type, src);
do_drain_end_unlocked(drain_type, drain_bs);
if (use_iothread) {
/* paused is reset in the I/O thread, wait for it */
@ -969,7 +1017,7 @@ static void test_blockjob_common(enum drain_type drain_type, bool use_iothread,
blk_unref(blk_src);
blk_unref(blk_target);
bdrv_unref(src);
bdrv_unref(src_overlay);
bdrv_unref(target);
if (iothread) {
@ -977,6 +1025,19 @@ static void test_blockjob_common(enum drain_type drain_type, bool use_iothread,
}
}
static void test_blockjob_common(enum drain_type drain_type, bool use_iothread,
enum test_job_result result)
{
test_blockjob_common_drain_node(drain_type, use_iothread, result,
TEST_JOB_DRAIN_SRC);
test_blockjob_common_drain_node(drain_type, use_iothread, result,
TEST_JOB_DRAIN_SRC_CHILD);
if (drain_type == BDRV_SUBTREE_DRAIN) {
test_blockjob_common_drain_node(drain_type, use_iothread, result,
TEST_JOB_DRAIN_SRC_PARENT);
}
}
static void test_blockjob_drain_all(void)
{
test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_SUCCESS);