nperm, nshared);
}
+static int bdrv_test_change_backing_file(BlockDriverState *bs,
+ const char *backing_file,
+ const char *backing_fmt)
+{
+ return 0;
+}
+
static BlockDriver bdrv_test = {
.format_name = "test",
.instance_size = sizeof(BDRVTestState),
.bdrv_co_drain_end = bdrv_test_co_drain_end,
.bdrv_child_perm = bdrv_test_child_perm,
+
+ .bdrv_change_backing_file = bdrv_test_change_backing_file,
};
static void aio_ret_cb(void *opaque, int ret)
BlockAIOCB *acb;
int aio_ret;
- QEMUIOVector qiov;
- struct iovec iov = {
- .iov_base = NULL,
- .iov_len = 0,
- };
- qemu_iovec_init_external(&qiov, &iov, 1);
+ QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0);
- blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+ blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
&error_abort);
s = bs->opaque;
BlockBackend *blk;
BlockDriverState *bs, *backing;
- blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+ blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
&error_abort);
blk_insert_bs(blk, bs, &error_abort);
BDRVTestState *s, *backing_s;
enum drain_type outer, inner;
- blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+ blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
&error_abort);
s = bs->opaque;
BlockDriverState *bs_a, *bs_b, *backing;
BDRVTestState *a_s, *b_s, *backing_s;
- blk_a = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+ blk_a = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR,
&error_abort);
a_s = bs_a->opaque;
blk_insert_bs(blk_a, bs_a, &error_abort);
- blk_b = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+ blk_b = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR,
&error_abort);
b_s = bs_b->opaque;
BlockDriverState *bs_a, *bs_b, *backing;
BDRVTestState *a_s, *b_s, *backing_s;
- blk_a = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+ blk_a = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR,
&error_abort);
a_s = bs_a->opaque;
blk_insert_bs(blk_a, bs_a, &error_abort);
- blk_b = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+ blk_b = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR,
&error_abort);
b_s = bs_b->opaque;
BDRVTestState *a_s, *b_s;
/* Create node A with a BlockBackend */
- blk_a = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+ blk_a = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR,
&error_abort);
a_s = bs_a->opaque;
g_assert_cmpint(a_s->drain_count, ==, 1);
/* Create node B with a BlockBackend */
- blk_b = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+ blk_b = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR,
&error_abort);
b_s = bs_b->opaque;
AioContext *ctx_a = iothread_get_aio_context(a);
AioContext *ctx_b = iothread_get_aio_context(b);
- QEMUIOVector qiov;
- struct iovec iov = {
- .iov_base = NULL,
- .iov_len = 0,
- };
- qemu_iovec_init_external(&qiov, &iov, 1);
+ QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0);
/* bdrv_drain_all() may only be called from the main loop thread */
if (drain_type == BDRV_DRAIN_ALL && drain_thread != 0) {
goto out;
}
- blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+ blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
&error_abort);
s = bs->opaque;
blk_insert_bs(blk, bs, &error_abort);
- blk_set_aio_context(blk, ctx_a);
+ blk_set_aio_context(blk, ctx_a, &error_abort);
aio_context_acquire(ctx_a);
s->bh_indirection_ctx = ctx_b;
aio_ret = -EINPROGRESS;
+ qemu_event_reset(&done_event);
+
if (drain_thread == 0) {
acb = blk_aio_preadv(blk, 0, &qiov, 0, test_iothread_aio_cb, &aio_ret);
} else {
* but the drain in this thread can continue immediately after
* bdrv_dec_in_flight() and aio_ret might be assigned only slightly
* later. */
- qemu_event_reset(&done_event);
do_drain_begin(drain_type, bs);
g_assert_cmpint(bs->in_flight, ==, 0);
}
break;
case 1:
- qemu_event_reset(&done_event);
aio_bh_schedule_oneshot(ctx_a, test_iothread_drain_entry, &data);
qemu_event_wait(&done_event);
break;
}
aio_context_acquire(ctx_a);
- blk_set_aio_context(blk, qemu_get_aio_context());
+ blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort);
aio_context_release(ctx_a);
bdrv_unref(bs);
typedef struct TestBlockJob {
BlockJob common;
+ int run_ret;
+ int prepare_ret;
+ bool running;
bool should_complete;
} TestBlockJob;
/* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */
blk_flush(s->common.blk);
- return 0;
+ return s->prepare_ret;
+}
+
+static void test_job_commit(Job *job)
+{
+ TestBlockJob *s = container_of(job, TestBlockJob, common.job);
+
+ /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */
+ blk_flush(s->common.blk);
+}
+
+static void test_job_abort(Job *job)
+{
+ TestBlockJob *s = container_of(job, TestBlockJob, common.job);
+
+ /* Provoke an AIO_WAIT_WHILE() call to verify there is no deadlock */
+ blk_flush(s->common.blk);
}
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 block_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 acitivity to stop. */
- qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 100000);
+ /* 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, 1000000);
+
job_pause_point(&s->common.job);
}
- return 0;
+ return s->run_ret;
}
static void test_job_complete(Job *job, Error **errp)
.run = test_job_run,
.complete = test_job_complete,
.prepare = test_job_prepare,
+ .commit = test_job_commit,
+ .abort = test_job_abort,
},
};
-static void test_blockjob_common(enum drain_type drain_type, bool use_iothread)
+enum test_job_result {
+ TEST_JOB_SUCCESS,
+ TEST_JOB_FAIL_RUN,
+ TEST_JOB_FAIL_PREPARE,
+};
+
+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;
AioContext *ctx;
int ret;
src = bdrv_new_open_driver(&bdrv_test, "source", BDRV_O_RDWR,
&error_abort);
- blk_src = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
- blk_insert_bs(blk_src, src, &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(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
+ 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();
ctx = iothread_get_aio_context(iothread);
- blk_set_aio_context(blk_src, ctx);
+ blk_set_aio_context(blk_src, ctx, &error_abort);
} else {
ctx = qemu_get_aio_context();
}
target = bdrv_new_open_driver(&bdrv_test, "target", BDRV_O_RDWR,
&error_abort);
- blk_target = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+ blk_target = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
blk_insert_bs(blk_target, target, &error_abort);
+ blk_set_allow_aio_context_change(blk_target, true);
aio_context_acquire(ctx);
- job = block_job_create("job0", &test_job_driver, NULL, src, 0, BLK_PERM_ALL,
- 0, 0, NULL, NULL, &error_abort);
+ tjob = block_job_create("job0", &test_job_driver, NULL, src,
+ 0, BLK_PERM_ALL,
+ 0, 0, NULL, NULL, &error_abort);
+ job = &tjob->common;
block_job_add_bdrv(job, "target", target, 0, BLK_PERM_ALL, &error_abort);
+
+ switch (result) {
+ case TEST_JOB_SUCCESS:
+ break;
+ case TEST_JOB_FAIL_RUN:
+ tjob->run_ret = -EIO;
+ break;
+ case TEST_JOB_FAIL_PREPARE:
+ tjob->prepare_ret = -EIO;
+ break;
+ }
+
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(job->job.busy); /* We're in job_sleep_ns() */
+ 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 */
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 */
g_assert_false(job->job.paused);
g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */
- do_drain_begin(drain_type, target);
+ do_drain_begin_unlocked(drain_type, target);
if (drain_type == BDRV_DRAIN_ALL) {
/* bdrv_drain_all() drains both src and target */
g_assert_true(job->job.paused);
g_assert_false(job->job.busy); /* The job is paused */
- do_drain_end(drain_type, target);
+ do_drain_end_unlocked(drain_type, target);
if (use_iothread) {
/* paused is reset in the I/O thread, wait for it */
g_assert_cmpint(job->job.pause_count, ==, 0);
g_assert_false(job->job.paused);
- g_assert_true(job->job.busy); /* We're in job_sleep_ns() */
+ g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */
aio_context_acquire(ctx);
ret = job_complete_sync(&job->job, &error_abort);
- g_assert_cmpint(ret, ==, 0);
+ g_assert_cmpint(ret, ==, (result == TEST_JOB_SUCCESS ? 0 : -EIO));
if (use_iothread) {
- blk_set_aio_context(blk_src, qemu_get_aio_context());
+ blk_set_aio_context(blk_src, qemu_get_aio_context(), &error_abort);
+ assert(blk_get_aio_context(blk_target) == qemu_get_aio_context());
}
aio_context_release(ctx);
blk_unref(blk_src);
blk_unref(blk_target);
- bdrv_unref(src);
+ bdrv_unref(src_overlay);
bdrv_unref(target);
if (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_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_SUCCESS);
}
static void test_blockjob_drain(void)
{
- test_blockjob_common(BDRV_DRAIN, false);
+ test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_SUCCESS);
}
static void test_blockjob_drain_subtree(void)
{
- test_blockjob_common(BDRV_SUBTREE_DRAIN, false);
+ test_blockjob_common(BDRV_SUBTREE_DRAIN, false, TEST_JOB_SUCCESS);
+}
+
+static void test_blockjob_error_drain_all(void)
+{
+ test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_FAIL_RUN);
+ test_blockjob_common(BDRV_DRAIN_ALL, false, TEST_JOB_FAIL_PREPARE);
+}
+
+static void test_blockjob_error_drain(void)
+{
+ test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_FAIL_RUN);
+ test_blockjob_common(BDRV_DRAIN, false, TEST_JOB_FAIL_PREPARE);
+}
+
+static void test_blockjob_error_drain_subtree(void)
+{
+ test_blockjob_common(BDRV_SUBTREE_DRAIN, false, TEST_JOB_FAIL_RUN);
+ test_blockjob_common(BDRV_SUBTREE_DRAIN, false, TEST_JOB_FAIL_PREPARE);
}
static void test_blockjob_iothread_drain_all(void)
{
- test_blockjob_common(BDRV_DRAIN_ALL, true);
+ test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_SUCCESS);
}
static void test_blockjob_iothread_drain(void)
{
- test_blockjob_common(BDRV_DRAIN, true);
+ test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_SUCCESS);
}
static void test_blockjob_iothread_drain_subtree(void)
{
- test_blockjob_common(BDRV_SUBTREE_DRAIN, true);
+ test_blockjob_common(BDRV_SUBTREE_DRAIN, true, TEST_JOB_SUCCESS);
+}
+
+static void test_blockjob_iothread_error_drain_all(void)
+{
+ test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_FAIL_RUN);
+ test_blockjob_common(BDRV_DRAIN_ALL, true, TEST_JOB_FAIL_PREPARE);
+}
+
+static void test_blockjob_iothread_error_drain(void)
+{
+ test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_FAIL_RUN);
+ test_blockjob_common(BDRV_DRAIN, true, TEST_JOB_FAIL_PREPARE);
+}
+
+static void test_blockjob_iothread_error_drain_subtree(void)
+{
+ test_blockjob_common(BDRV_SUBTREE_DRAIN, true, TEST_JOB_FAIL_RUN);
+ test_blockjob_common(BDRV_SUBTREE_DRAIN, true, TEST_JOB_FAIL_PREPARE);
}
BlockDriverState *bs = blk_bs(blk);
BDRVTestTopState *tts = bs->opaque;
void *buffer = g_malloc(65536);
- QEMUIOVector qiov;
- struct iovec iov = {
- .iov_base = buffer,
- .iov_len = 65536,
- };
-
- qemu_iovec_init_external(&qiov, &iov, 1);
+ QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buffer, 65536);
/* Pretend some internal write operation from parent to child.
* Important: We have to read from the child, not from the parent!
&error_abort);
bdrv_attach_child(bs, null_bs, "null-child", &child_file, &error_abort);
- blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+ blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
blk_insert_bs(blk, bs, &error_abort);
/* Referenced by blk now */
BdrvChild *child_a, *child_b;
BlockAIOCB *acb;
- QEMUIOVector qiov;
- struct iovec iov = {
- .iov_base = NULL,
- .iov_len = 0,
- };
- qemu_iovec_init_external(&qiov, &iov, 1);
+ QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0);
if (!by_parent_cb) {
detach_by_driver_cb_role = child_file;
c = bdrv_new_open_driver(&bdrv_test, "c", BDRV_O_RDWR, &error_abort);
/* blk is a BB for parent-a */
- blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+ blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
blk_insert_bs(blk, parent_a, &error_abort);
bdrv_unref(parent_a);
bdrv_unref(parent_b);
blk_unref(blk);
- /* XXX Once bdrv_close() unref's children instead of just detaching them,
- * this won't be necessary any more. */
- bdrv_unref(a);
- bdrv_unref(a);
- bdrv_unref(c);
-
g_assert_cmpint(a->refcnt, ==, 1);
g_assert_cmpint(b->refcnt, ==, 1);
g_assert_cmpint(c->refcnt, ==, 1);
BlockDriverState *base, *overlay;
BDRVTestState *base_s, *overlay_s;
- blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+ blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
base = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort);
base_s = base->opaque;
blk_insert_bs(blk, base, &error_abort);
blk_unref(blk);
}
+static void test_set_aio_context(void)
+{
+ BlockDriverState *bs;
+ IOThread *a = iothread_new();
+ IOThread *b = iothread_new();
+ AioContext *ctx_a = iothread_get_aio_context(a);
+ AioContext *ctx_b = iothread_get_aio_context(b);
+
+ bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
+ &error_abort);
+
+ bdrv_drained_begin(bs);
+ bdrv_try_set_aio_context(bs, ctx_a, &error_abort);
+
+ aio_context_acquire(ctx_a);
+ bdrv_drained_end(bs);
+
+ bdrv_drained_begin(bs);
+ bdrv_try_set_aio_context(bs, ctx_b, &error_abort);
+ aio_context_release(ctx_a);
+ aio_context_acquire(ctx_b);
+ bdrv_try_set_aio_context(bs, qemu_get_aio_context(), &error_abort);
+ aio_context_release(ctx_b);
+ bdrv_drained_end(bs);
+
+ bdrv_unref(bs);
+ iothread_join(a);
+ iothread_join(b);
+}
+
+
+typedef struct TestDropBackingBlockJob {
+ BlockJob common;
+ bool should_complete;
+ bool *did_complete;
+ BlockDriverState *detach_also;
+} TestDropBackingBlockJob;
+
+static int coroutine_fn test_drop_backing_job_run(Job *job, Error **errp)
+{
+ TestDropBackingBlockJob *s =
+ container_of(job, TestDropBackingBlockJob, common.job);
+
+ while (!s->should_complete) {
+ job_sleep_ns(job, 0);
+ }
+
+ return 0;
+}
+
+static void test_drop_backing_job_commit(Job *job)
+{
+ TestDropBackingBlockJob *s =
+ container_of(job, TestDropBackingBlockJob, common.job);
+
+ bdrv_set_backing_hd(blk_bs(s->common.blk), NULL, &error_abort);
+ bdrv_set_backing_hd(s->detach_also, NULL, &error_abort);
+
+ *s->did_complete = true;
+}
+
+static const BlockJobDriver test_drop_backing_job_driver = {
+ .job_driver = {
+ .instance_size = sizeof(TestDropBackingBlockJob),
+ .free = block_job_free,
+ .user_resume = block_job_user_resume,
+ .drain = block_job_drain,
+ .run = test_drop_backing_job_run,
+ .commit = test_drop_backing_job_commit,
+ }
+};
+
+/**
+ * Creates a child node with three parent nodes on it, and then runs a
+ * block job on the final one, parent-node-2.
+ *
+ * The job is then asked to complete before a section where the child
+ * is drained.
+ *
+ * Ending this section will undrain the child's parents, first
+ * parent-node-2, then parent-node-1, then parent-node-0 -- the parent
+ * list is in reverse order of how they were added. Ending the drain
+ * on parent-node-2 will resume the job, thus completing it and
+ * scheduling job_exit().
+ *
+ * Ending the drain on parent-node-1 will poll the AioContext, which
+ * lets job_exit() and thus test_drop_backing_job_commit() run. That
+ * function first removes the child as parent-node-2's backing file.
+ *
+ * In old (and buggy) implementations, there are two problems with
+ * that:
+ * (A) bdrv_drain_invoke() polls for every node that leaves the
+ * drained section. This means that job_exit() is scheduled
+ * before the child has left the drained section. Its
+ * quiesce_counter is therefore still 1 when it is removed from
+ * parent-node-2.
+ *
+ * (B) bdrv_replace_child_noperm() calls drained_end() on the old
+ * child's parents as many times as the child is quiesced. This
+ * means it will call drained_end() on parent-node-2 once.
+ * Because parent-node-2 is no longer quiesced at this point, this
+ * will fail.
+ *
+ * bdrv_replace_child_noperm() therefore must call drained_end() on
+ * the parent only if it really is still drained because the child is
+ * drained.
+ *
+ * If removing child from parent-node-2 was successful (as it should
+ * be), test_drop_backing_job_commit() will then also remove the child
+ * from parent-node-0.
+ *
+ * With an old version of our drain infrastructure ((A) above), that
+ * resulted in the following flow:
+ *
+ * 1. child attempts to leave its drained section. The call recurses
+ * to its parents.
+ *
+ * 2. parent-node-2 leaves the drained section. Polling in
+ * bdrv_drain_invoke() will schedule job_exit().
+ *
+ * 3. parent-node-1 leaves the drained section. Polling in
+ * bdrv_drain_invoke() will run job_exit(), thus disconnecting
+ * parent-node-0 from the child node.
+ *
+ * 4. bdrv_parent_drained_end() uses a QLIST_FOREACH_SAFE() loop to
+ * iterate over the parents. Thus, it now accesses the BdrvChild
+ * object that used to connect parent-node-0 and the child node.
+ * However, that object no longer exists, so it accesses a dangling
+ * pointer.
+ *
+ * The solution is to only poll once when running a bdrv_drained_end()
+ * operation, specifically at the end when all drained_end()
+ * operations for all involved nodes have been scheduled.
+ * Note that this also solves (A) above, thus hiding (B).
+ */
+static void test_blockjob_commit_by_drained_end(void)
+{
+ BlockDriverState *bs_child, *bs_parents[3];
+ TestDropBackingBlockJob *job;
+ bool job_has_completed = false;
+ int i;
+
+ bs_child = bdrv_new_open_driver(&bdrv_test, "child-node", BDRV_O_RDWR,
+ &error_abort);
+
+ for (i = 0; i < 3; i++) {
+ char name[32];
+ snprintf(name, sizeof(name), "parent-node-%i", i);
+ bs_parents[i] = bdrv_new_open_driver(&bdrv_test, name, BDRV_O_RDWR,
+ &error_abort);
+ bdrv_set_backing_hd(bs_parents[i], bs_child, &error_abort);
+ }
+
+ job = block_job_create("job", &test_drop_backing_job_driver, NULL,
+ bs_parents[2], 0, BLK_PERM_ALL, 0, 0, NULL, NULL,
+ &error_abort);
+
+ job->detach_also = bs_parents[0];
+ job->did_complete = &job_has_completed;
+
+ job_start(&job->common.job);
+
+ job->should_complete = true;
+ bdrv_drained_begin(bs_child);
+ g_assert(!job_has_completed);
+ bdrv_drained_end(bs_child);
+ g_assert(job_has_completed);
+
+ bdrv_unref(bs_parents[0]);
+ bdrv_unref(bs_parents[1]);
+ bdrv_unref(bs_parents[2]);
+ bdrv_unref(bs_child);
+}
+
+
+typedef struct TestSimpleBlockJob {
+ BlockJob common;
+ bool should_complete;
+ bool *did_complete;
+} TestSimpleBlockJob;
+
+static int coroutine_fn test_simple_job_run(Job *job, Error **errp)
+{
+ TestSimpleBlockJob *s = container_of(job, TestSimpleBlockJob, common.job);
+
+ while (!s->should_complete) {
+ job_sleep_ns(job, 0);
+ }
+
+ return 0;
+}
+
+static void test_simple_job_clean(Job *job)
+{
+ TestSimpleBlockJob *s = container_of(job, TestSimpleBlockJob, common.job);
+ *s->did_complete = true;
+}
+
+static const BlockJobDriver test_simple_job_driver = {
+ .job_driver = {
+ .instance_size = sizeof(TestSimpleBlockJob),
+ .free = block_job_free,
+ .user_resume = block_job_user_resume,
+ .drain = block_job_drain,
+ .run = test_simple_job_run,
+ .clean = test_simple_job_clean,
+ },
+};
+
+static int drop_intermediate_poll_update_filename(BdrvChild *child,
+ BlockDriverState *new_base,
+ const char *filename,
+ Error **errp)
+{
+ /*
+ * We are free to poll here, which may change the block graph, if
+ * it is not drained.
+ */
+
+ /* If the job is not drained: Complete it, schedule job_exit() */
+ aio_poll(qemu_get_current_aio_context(), false);
+ /* If the job is not drained: Run job_exit(), finish the job */
+ aio_poll(qemu_get_current_aio_context(), false);
+
+ return 0;
+}
+
+/**
+ * Test a poll in the midst of bdrv_drop_intermediate().
+ *
+ * bdrv_drop_intermediate() calls BdrvChildRole.update_filename(),
+ * which can yield or poll. This may lead to graph changes, unless
+ * the whole subtree in question is drained.
+ *
+ * We test this on the following graph:
+ *
+ * Job
+ *
+ * |
+ * job-node
+ * |
+ * v
+ *
+ * job-node
+ *
+ * |
+ * backing
+ * |
+ * v
+ *
+ * node-2 --chain--> node-1 --chain--> node-0
+ *
+ * We drop node-1 with bdrv_drop_intermediate(top=node-1, base=node-0).
+ *
+ * This first updates node-2's backing filename by invoking
+ * drop_intermediate_poll_update_filename(), which polls twice. This
+ * causes the job to finish, which in turns causes the job-node to be
+ * deleted.
+ *
+ * bdrv_drop_intermediate() uses a QLIST_FOREACH_SAFE() loop, so it
+ * already has a pointer to the BdrvChild edge between job-node and
+ * node-1. When it tries to handle that edge, we probably get a
+ * segmentation fault because the object no longer exists.
+ *
+ *
+ * The solution is for bdrv_drop_intermediate() to drain top's
+ * subtree. This prevents graph changes from happening just because
+ * BdrvChildRole.update_filename() yields or polls. Thus, the block
+ * job is paused during that drained section and must finish before or
+ * after.
+ *
+ * (In addition, bdrv_replace_child() must keep the job paused.)
+ */
+static void test_drop_intermediate_poll(void)
+{
+ static BdrvChildRole chain_child_role;
+ BlockDriverState *chain[3];
+ TestSimpleBlockJob *job;
+ BlockDriverState *job_node;
+ bool job_has_completed = false;
+ int i;
+ int ret;
+
+ chain_child_role = child_backing;
+ chain_child_role.update_filename = drop_intermediate_poll_update_filename;
+
+ for (i = 0; i < 3; i++) {
+ char name[32];
+ snprintf(name, 32, "node-%i", i);
+
+ chain[i] = bdrv_new_open_driver(&bdrv_test, name, 0, &error_abort);
+ }
+
+ job_node = bdrv_new_open_driver(&bdrv_test, "job-node", BDRV_O_RDWR,
+ &error_abort);
+ bdrv_set_backing_hd(job_node, chain[1], &error_abort);
+
+ /*
+ * Establish the chain last, so the chain links are the first
+ * elements in the BDS.parents lists
+ */
+ for (i = 0; i < 3; i++) {
+ if (i) {
+ /* Takes the reference to chain[i - 1] */
+ chain[i]->backing = bdrv_attach_child(chain[i], chain[i - 1],
+ "chain", &chain_child_role,
+ &error_abort);
+ }
+ }
+
+ job = block_job_create("job", &test_simple_job_driver, NULL, job_node,
+ 0, BLK_PERM_ALL, 0, 0, NULL, NULL, &error_abort);
+
+ /* The job has a reference now */
+ bdrv_unref(job_node);
+
+ job->did_complete = &job_has_completed;
+
+ job_start(&job->common.job);
+ job->should_complete = true;
+
+ g_assert(!job_has_completed);
+ ret = bdrv_drop_intermediate(chain[1], chain[0], NULL);
+ g_assert(ret == 0);
+ g_assert(job_has_completed);
+
+ bdrv_unref(chain[2]);
+}
+
+
+typedef struct BDRVReplaceTestState {
+ bool was_drained;
+ bool was_undrained;
+ bool has_read;
+
+ int drain_count;
+
+ bool yield_before_read;
+ Coroutine *io_co;
+ Coroutine *drain_co;
+} BDRVReplaceTestState;
+
+static void bdrv_replace_test_close(BlockDriverState *bs)
+{
+}
+
+/**
+ * If @bs has a backing file:
+ * Yield if .yield_before_read is true (and wait for drain_begin to
+ * wake us up).
+ * Forward the read to bs->backing. Set .has_read to true.
+ * If drain_begin has woken us, wake it in turn.
+ *
+ * Otherwise:
+ * Set .has_read to true and return success.
+ */
+static int coroutine_fn bdrv_replace_test_co_preadv(BlockDriverState *bs,
+ uint64_t offset,
+ uint64_t bytes,
+ QEMUIOVector *qiov,
+ int flags)
+{
+ BDRVReplaceTestState *s = bs->opaque;
+
+ if (bs->backing) {
+ int ret;
+
+ g_assert(!s->drain_count);
+
+ s->io_co = qemu_coroutine_self();
+ if (s->yield_before_read) {
+ s->yield_before_read = false;
+ qemu_coroutine_yield();
+ }
+ s->io_co = NULL;
+
+ ret = bdrv_preadv(bs->backing, offset, qiov);
+ s->has_read = true;
+
+ /* Wake up drain_co if it runs */
+ if (s->drain_co) {
+ aio_co_wake(s->drain_co);
+ }
+
+ return ret;
+ }
+
+ s->has_read = true;
+ return 0;
+}
+
+/**
+ * If .drain_count is 0, wake up .io_co if there is one; and set
+ * .was_drained.
+ * Increment .drain_count.
+ */
+static void coroutine_fn bdrv_replace_test_co_drain_begin(BlockDriverState *bs)
+{
+ BDRVReplaceTestState *s = bs->opaque;
+
+ if (!s->drain_count) {
+ /* Keep waking io_co up until it is done */
+ s->drain_co = qemu_coroutine_self();
+ while (s->io_co) {
+ aio_co_wake(s->io_co);
+ s->io_co = NULL;
+ qemu_coroutine_yield();
+ }
+ s->drain_co = NULL;
+
+ s->was_drained = true;
+ }
+ s->drain_count++;
+}
+
+/**
+ * Reduce .drain_count, set .was_undrained once it reaches 0.
+ * If .drain_count reaches 0 and the node has a backing file, issue a
+ * read request.
+ */
+static void coroutine_fn bdrv_replace_test_co_drain_end(BlockDriverState *bs)
+{
+ BDRVReplaceTestState *s = bs->opaque;
+
+ g_assert(s->drain_count > 0);
+ if (!--s->drain_count) {
+ int ret;
+
+ s->was_undrained = true;
+
+ if (bs->backing) {
+ char data;
+ QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, &data, 1);
+
+ /* Queue a read request post-drain */
+ ret = bdrv_replace_test_co_preadv(bs, 0, 1, &qiov, 0);
+ g_assert(ret >= 0);
+ }
+ }
+}
+
+static BlockDriver bdrv_replace_test = {
+ .format_name = "replace_test",
+ .instance_size = sizeof(BDRVReplaceTestState),
+
+ .bdrv_close = bdrv_replace_test_close,
+ .bdrv_co_preadv = bdrv_replace_test_co_preadv,
+
+ .bdrv_co_drain_begin = bdrv_replace_test_co_drain_begin,
+ .bdrv_co_drain_end = bdrv_replace_test_co_drain_end,
+
+ .bdrv_child_perm = bdrv_format_default_perms,
+};
+
+static void coroutine_fn test_replace_child_mid_drain_read_co(void *opaque)
+{
+ int ret;
+ char data;
+
+ ret = blk_co_pread(opaque, 0, 1, &data, 0);
+ g_assert(ret >= 0);
+}
+
+/**
+ * We test two things:
+ * (1) bdrv_replace_child_noperm() must not undrain the parent if both
+ * children are drained.
+ * (2) bdrv_replace_child_noperm() must never flush I/O requests to a
+ * drained child. If the old child is drained, it must flush I/O
+ * requests after the new one has been attached. If the new child
+ * is drained, it must flush I/O requests before the old one is
+ * detached.
+ *
+ * To do so, we create one parent node and two child nodes; then
+ * attach one of the children (old_child_bs) to the parent, then
+ * drain both old_child_bs and new_child_bs according to
+ * old_drain_count and new_drain_count, respectively, and finally
+ * we invoke bdrv_replace_node() to replace old_child_bs by
+ * new_child_bs.
+ *
+ * The test block driver we use here (bdrv_replace_test) has a read
+ * function that:
+ * - For the parent node, can optionally yield, and then forwards the
+ * read to bdrv_preadv(),
+ * - For the child node, just returns immediately.
+ *
+ * If the read yields, the drain_begin function will wake it up.
+ *
+ * The drain_end function issues a read on the parent once it is fully
+ * undrained (which simulates requests starting to come in again).
+ */
+static void do_test_replace_child_mid_drain(int old_drain_count,
+ int new_drain_count)
+{
+ BlockBackend *parent_blk;
+ BlockDriverState *parent_bs;
+ BlockDriverState *old_child_bs, *new_child_bs;
+ BDRVReplaceTestState *parent_s;
+ BDRVReplaceTestState *old_child_s, *new_child_s;
+ Coroutine *io_co;
+ int i;
+
+ parent_bs = bdrv_new_open_driver(&bdrv_replace_test, "parent", 0,
+ &error_abort);
+ parent_s = parent_bs->opaque;
+
+ parent_blk = blk_new(qemu_get_aio_context(),
+ BLK_PERM_CONSISTENT_READ, BLK_PERM_ALL);
+ blk_insert_bs(parent_blk, parent_bs, &error_abort);
+
+ old_child_bs = bdrv_new_open_driver(&bdrv_replace_test, "old-child", 0,
+ &error_abort);
+ new_child_bs = bdrv_new_open_driver(&bdrv_replace_test, "new-child", 0,
+ &error_abort);
+ old_child_s = old_child_bs->opaque;
+ new_child_s = new_child_bs->opaque;
+
+ /* So that we can read something */
+ parent_bs->total_sectors = 1;
+ old_child_bs->total_sectors = 1;
+ new_child_bs->total_sectors = 1;
+
+ bdrv_ref(old_child_bs);
+ parent_bs->backing = bdrv_attach_child(parent_bs, old_child_bs, "child",
+ &child_backing, &error_abort);
+
+ for (i = 0; i < old_drain_count; i++) {
+ bdrv_drained_begin(old_child_bs);
+ }
+ for (i = 0; i < new_drain_count; i++) {
+ bdrv_drained_begin(new_child_bs);
+ }
+
+ if (!old_drain_count) {
+ /*
+ * Start a read operation that will yield, so it will not
+ * complete before the node is drained.
+ */
+ parent_s->yield_before_read = true;
+ io_co = qemu_coroutine_create(test_replace_child_mid_drain_read_co,
+ parent_blk);
+ qemu_coroutine_enter(io_co);
+ }
+
+ /* If we have started a read operation, it should have yielded */
+ g_assert(!parent_s->has_read);
+
+ /* Reset drained status so we can see what bdrv_replace_node() does */
+ parent_s->was_drained = false;
+ parent_s->was_undrained = false;
+
+ g_assert(parent_bs->quiesce_counter == old_drain_count);
+ bdrv_replace_node(old_child_bs, new_child_bs, &error_abort);
+ g_assert(parent_bs->quiesce_counter == new_drain_count);
+
+ if (!old_drain_count && !new_drain_count) {
+ /*
+ * From undrained to undrained drains and undrains the parent,
+ * because bdrv_replace_node() contains a drained section for
+ * @old_child_bs.
+ */
+ g_assert(parent_s->was_drained && parent_s->was_undrained);
+ } else if (!old_drain_count && new_drain_count) {
+ /*
+ * From undrained to drained should drain the parent and keep
+ * it that way.
+ */
+ g_assert(parent_s->was_drained && !parent_s->was_undrained);
+ } else if (old_drain_count && !new_drain_count) {
+ /*
+ * From drained to undrained should undrain the parent and
+ * keep it that way.
+ */
+ g_assert(!parent_s->was_drained && parent_s->was_undrained);
+ } else /* if (old_drain_count && new_drain_count) */ {
+ /*
+ * From drained to drained must not undrain the parent at any
+ * point
+ */
+ g_assert(!parent_s->was_drained && !parent_s->was_undrained);
+ }
+
+ if (!old_drain_count || !new_drain_count) {
+ /*
+ * If !old_drain_count, we have started a read request before
+ * bdrv_replace_node(). If !new_drain_count, the parent must
+ * have been undrained at some point, and
+ * bdrv_replace_test_co_drain_end() starts a read request
+ * then.
+ */
+ g_assert(parent_s->has_read);
+ } else {
+ /*
+ * If the parent was never undrained, there is no way to start
+ * a read request.
+ */
+ g_assert(!parent_s->has_read);
+ }
+
+ /* A drained child must have not received any request */
+ g_assert(!(old_drain_count && old_child_s->has_read));
+ g_assert(!(new_drain_count && new_child_s->has_read));
+
+ for (i = 0; i < new_drain_count; i++) {
+ bdrv_drained_end(new_child_bs);
+ }
+ for (i = 0; i < old_drain_count; i++) {
+ bdrv_drained_end(old_child_bs);
+ }
+
+ /*
+ * By now, bdrv_replace_test_co_drain_end() must have been called
+ * at some point while the new child was attached to the parent.
+ */
+ g_assert(parent_s->has_read);
+ g_assert(new_child_s->has_read);
+
+ blk_unref(parent_blk);
+ bdrv_unref(parent_bs);
+ bdrv_unref(old_child_bs);
+ bdrv_unref(new_child_bs);
+}
+
+static void test_replace_child_mid_drain(void)
+{
+ int old_drain_count, new_drain_count;
+
+ for (old_drain_count = 0; old_drain_count < 2; old_drain_count++) {
+ for (new_drain_count = 0; new_drain_count < 2; new_drain_count++) {
+ do_test_replace_child_mid_drain(old_drain_count, new_drain_count);
+ }
+ }
+}
+
int main(int argc, char **argv)
{
int ret;
g_test_add_func("/bdrv-drain/blockjob/drain_subtree",
test_blockjob_drain_subtree);
+ g_test_add_func("/bdrv-drain/blockjob/error/drain_all",
+ test_blockjob_error_drain_all);
+ g_test_add_func("/bdrv-drain/blockjob/error/drain",
+ test_blockjob_error_drain);
+ g_test_add_func("/bdrv-drain/blockjob/error/drain_subtree",
+ test_blockjob_error_drain_subtree);
+
g_test_add_func("/bdrv-drain/blockjob/iothread/drain_all",
test_blockjob_iothread_drain_all);
g_test_add_func("/bdrv-drain/blockjob/iothread/drain",
g_test_add_func("/bdrv-drain/blockjob/iothread/drain_subtree",
test_blockjob_iothread_drain_subtree);
+ g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain_all",
+ test_blockjob_iothread_error_drain_all);
+ g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain",
+ test_blockjob_iothread_error_drain);
+ g_test_add_func("/bdrv-drain/blockjob/iothread/error/drain_subtree",
+ test_blockjob_iothread_error_drain_subtree);
+
g_test_add_func("/bdrv-drain/deletion/drain", test_delete_by_drain);
g_test_add_func("/bdrv-drain/detach/drain_all", test_detach_by_drain_all);
g_test_add_func("/bdrv-drain/detach/drain", test_detach_by_drain);
g_test_add_func("/bdrv-drain/attach/drain", test_append_to_drained);
+ g_test_add_func("/bdrv-drain/set_aio_context", test_set_aio_context);
+
+ g_test_add_func("/bdrv-drain/blockjob/commit_by_drained_end",
+ test_blockjob_commit_by_drained_end);
+
+ g_test_add_func("/bdrv-drain/bdrv_drop_intermediate/poll",
+ test_drop_intermediate_poll);
+
+ g_test_add_func("/bdrv-drain/replace_child/mid-drain",
+ test_replace_child_mid_drain);
+
ret = g_test_run();
qemu_event_destroy(&done_event);
return ret;
projects / qemu.git / blobdiff