Commit d8b3afd5 authored by Kevin Wolf's avatar Kevin Wolf
Browse files

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: default avatarKevin Wolf <kwolf@redhat.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
Reviewed-by: default avatarMax Reitz <mreitz@redhat.com>
parent cfe29d82

tests/test-bdrv-drain.c

+69 −8
Original line number Diff line number Diff line
@@ -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);