From f90f3f9a94cb09c3d568fbc9dc338b5f8c5ea17c Mon Sep 17 00:00:00 2001

From: Kevin Wolf <kwolf@redhat.com>

Date: Wed, 10 Oct 2018 20:22:13 +0100

Subject: [PATCH 47/49] test-bdrv-drain: Test draining job source child and

 parent

RH-Author: Kevin Wolf <kwolf@redhat.com>

Message-id: <20181010202213.7372-35-kwolf@redhat.com>

Patchwork-id: 82624

O-Subject: [RHEL-8 qemu-kvm PATCH 44/44] test-bdrv-drain: Test draining job source child and parent

Bugzilla: 1637976

RH-Acked-by: Max Reitz <mreitz@redhat.com>

RH-Acked-by: John Snow <jsnow@redhat.com>

RH-Acked-by: Thomas Huth <thuth@redhat.com>

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>

(cherry picked from commit d8b3afd597d54e496809b05ac39ac29a5799664f)

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 tests/test-bdrv-drain.c | 77 ++++++++++++++++++++++++++++++++++++++++++++-----

 1 file changed, 69 insertions(+), 8 deletions(-)

diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c

index 7e7ba9b..8641b54 100644

--- a/tests/test-bdrv-drain.c

+++ b/tests/test-bdrv-drain.c

@@ -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);

-- 

1.8.3.1