Merge remote-tracking branch 'stefanha/block-next' into staging

# By Stefan Hajnoczi
# Via Stefan Hajnoczi
* stefanha/block-next:
  aio: drop io_flush argument
  tests: drop event_active_cb()
  thread-pool: drop thread_pool_active()
  dataplane/virtio-blk: drop flush_true() and flush_io()
  block/ssh: drop return_true()
  block/sheepdog: drop have_co_req() and aio_flush_request()
  block/rbd: drop qemu_rbd_aio_flush_cb()
  block/nbd: drop nbd_have_request()
  block/linux-aio: drop qemu_laio_completion_cb()
  block/iscsi: drop iscsi_process_flush()
  block/gluster: drop qemu_gluster_aio_flush_cb()
  block/curl: drop curl_aio_flush()
  aio: stop using .io_flush()
  tests: adjust test-thread-pool to new aio_poll() semantics
  tests: adjust test-aio to new aio_poll() semantics
  dataplane/virtio-blk: check exit conditions before aio_poll()
  block: stop relying on io_flush() in bdrv_drain_all()
  block: ensure bdrv_drain_all() works during bdrv_delete()

Message-id: 1376921877-9576-1-git-send-email-stefanha@redhat.com
Signed-off-by: Anthony Liguori <anthony@codemonkey.ws>

19 files changed, 163 insertions, 289 deletions

diff --git a/aio-posix.c b/aio-posix.c
index b68eccd40c..2440eb9c27 100644
--- a/aio-posix.c
+++ b/aio-posix.c
@@ -23,7 +23,6 @@ struct AioHandler
     GPollFD pfd;
     IOHandler *io_read;
     IOHandler *io_write;
-    AioFlushHandler *io_flush;
     int deleted;
     int pollfds_idx;
     void *opaque;
@@ -47,7 +46,6 @@ void aio_set_fd_handler(AioContext *ctx,
                         int fd,
                         IOHandler *io_read,
                         IOHandler *io_write,
-                        AioFlushHandler *io_flush,
                         void *opaque)
 {
     AioHandler *node;
@@ -84,7 +82,6 @@ void aio_set_fd_handler(AioContext *ctx,
         /* Update handler with latest information */
         node->io_read = io_read;
         node->io_write = io_write;
-        node->io_flush = io_flush;
         node->opaque = opaque;
         node->pollfds_idx = -1;
 
@@ -97,12 +94,10 @@ void aio_set_fd_handler(AioContext *ctx,
 
 void aio_set_event_notifier(AioContext *ctx,
                             EventNotifier *notifier,
-                            EventNotifierHandler *io_read,
-                            AioFlushEventNotifierHandler *io_flush)
+                            EventNotifierHandler *io_read)
 {
     aio_set_fd_handler(ctx, event_notifier_get_fd(notifier),
-                       (IOHandler *)io_read, NULL,
-                       (AioFlushHandler *)io_flush, notifier);
+                       (IOHandler *)io_read, NULL, notifier);
 }
 
 bool aio_pending(AioContext *ctx)
@@ -147,7 +142,11 @@ static bool aio_dispatch(AioContext *ctx)
             (revents & (G_IO_IN | G_IO_HUP | G_IO_ERR)) &&
             node->io_read) {
             node->io_read(node->opaque);
-            progress = true;
+
+            /* aio_notify() does not count as progress */
+            if (node->opaque != &ctx->notifier) {
+                progress = true;
+            }
         }
         if (!node->deleted &&
             (revents & (G_IO_OUT | G_IO_ERR)) &&
@@ -173,7 +172,7 @@ bool aio_poll(AioContext *ctx, bool blocking)
 {
     AioHandler *node;
     int ret;
-    bool busy, progress;
+    bool progress;
 
     progress = false;
 
@@ -200,20 +199,8 @@ bool aio_poll(AioContext *ctx, bool blocking)
     g_array_set_size(ctx->pollfds, 0);
 
     /* fill pollfds */
-    busy = false;
     QLIST_FOREACH(node, &ctx->aio_handlers, node) {
         node->pollfds_idx = -1;
-
-        /* If there aren't pending AIO operations, don't invoke callbacks.
-         * Otherwise, if there are no AIO requests, qemu_aio_wait() would
-         * wait indefinitely.
-         */
-        if (!node->deleted && node->io_flush) {
-            if (node->io_flush(node->opaque) == 0) {
-                continue;
-            }
-            busy = true;
-        }
         if (!node->deleted && node->pfd.events) {
             GPollFD pfd = {
                 .fd = node->pfd.fd,
@@ -226,8 +213,8 @@ bool aio_poll(AioContext *ctx, bool blocking)
 
     ctx->walking_handlers--;
 
-    /* No AIO operations?  Get us out of here */
-    if (!busy) {
+    /* early return if we only have the aio_notify() fd */
+    if (ctx->pollfds->len == 1) {
         return progress;
     }
 
@@ -250,6 +237,5 @@ bool aio_poll(AioContext *ctx, bool blocking)
         }
     }
 
-    assert(progress || busy);
-    return true;
+    return progress;
 }
diff --git a/aio-win32.c b/aio-win32.c
index 38723bf1d3..78b2801c51 100644
--- a/aio-win32.c
+++ b/aio-win32.c
@@ -23,7 +23,6 @@
 struct AioHandler {
     EventNotifier *e;
     EventNotifierHandler *io_notify;
-    AioFlushEventNotifierHandler *io_flush;
     GPollFD pfd;
     int deleted;
     QLIST_ENTRY(AioHandler) node;
@@ -31,8 +30,7 @@ struct AioHandler {
 
 void aio_set_event_notifier(AioContext *ctx,
                             EventNotifier *e,
-                            EventNotifierHandler *io_notify,
-                            AioFlushEventNotifierHandler *io_flush)
+                            EventNotifierHandler *io_notify)
 {
     AioHandler *node;
 
@@ -73,7 +71,6 @@ void aio_set_event_notifier(AioContext *ctx,
         }
         /* Update handler with latest information */
         node->io_notify = io_notify;
-        node->io_flush = io_flush;
     }
 
     aio_notify(ctx);
@@ -96,7 +93,7 @@ bool aio_poll(AioContext *ctx, bool blocking)
 {
     AioHandler *node;
     HANDLE events[MAXIMUM_WAIT_OBJECTS + 1];
-    bool busy, progress;
+    bool progress;
     int count;
 
     progress = false;
@@ -126,7 +123,11 @@ bool aio_poll(AioContext *ctx, bool blocking)
         if (node->pfd.revents && node->io_notify) {
             node->pfd.revents = 0;
             node->io_notify(node->e);
-            progress = true;
+
+            /* aio_notify() does not count as progress */
+            if (node->opaque != &ctx->notifier) {
+                progress = true;
+            }
         }
 
         tmp = node;
@@ -147,19 +148,8 @@ bool aio_poll(AioContext *ctx, bool blocking)
     ctx->walking_handlers++;
 
     /* fill fd sets */
-    busy = false;
     count = 0;
     QLIST_FOREACH(node, &ctx->aio_handlers, node) {
-        /* If there aren't pending AIO operations, don't invoke callbacks.
-         * Otherwise, if there are no AIO requests, qemu_aio_wait() would
-         * wait indefinitely.
-         */
-        if (!node->deleted && node->io_flush) {
-            if (node->io_flush(node->e) == 0) {
-                continue;
-            }
-            busy = true;
-        }
         if (!node->deleted && node->io_notify) {
             events[count++] = event_notifier_get_handle(node->e);
         }
@@ -167,8 +157,8 @@ bool aio_poll(AioContext *ctx, bool blocking)
 
     ctx->walking_handlers--;
 
-    /* No AIO operations?  Get us out of here */
-    if (!busy) {
+    /* early return if we only have the aio_notify() fd */
+    if (count == 1) {
         return progress;
     }
 
@@ -196,7 +186,11 @@ bool aio_poll(AioContext *ctx, bool blocking)
                 event_notifier_get_handle(node->e) == events[ret - WAIT_OBJECT_0] &&
                 node->io_notify) {
                 node->io_notify(node->e);
-                progress = true;
+
+                /* aio_notify() does not count as progress */
+                if (node->opaque != &ctx->notifier) {
+                    progress = true;
+                }
             }
 
             tmp = node;
@@ -214,6 +208,5 @@ bool aio_poll(AioContext *ctx, bool blocking)
         events[ret - WAIT_OBJECT_0] = events[--count];
     }
 
-    assert(progress || busy);
-    return true;
+    return progress;
 }
diff --git a/async.c b/async.c
index 5ce3633010..9791d8e6a1 100644
--- a/async.c
+++ b/async.c
@@ -201,7 +201,7 @@ aio_ctx_finalize(GSource     *source)
     AioContext *ctx = (AioContext *) source;
 
     thread_pool_free(ctx->thread_pool);
-    aio_set_event_notifier(ctx, &ctx->notifier, NULL, NULL);
+    aio_set_event_notifier(ctx, &ctx->notifier, NULL);
     event_notifier_cleanup(&ctx->notifier);
     qemu_mutex_destroy(&ctx->bh_lock);
     g_array_free(ctx->pollfds, TRUE);
@@ -243,7 +243,7 @@ AioContext *aio_context_new(void)
     event_notifier_init(&ctx->notifier, false);
     aio_set_event_notifier(ctx, &ctx->notifier, 
                            (EventNotifierHandler *)
-                           event_notifier_test_and_clear, NULL);
+                           event_notifier_test_and_clear);
 
     return ctx;
 }
diff --git a/block.c b/block.c
index 01b66d802a..45a545bf10 100644
--- a/block.c
+++ b/block.c
@@ -148,7 +148,6 @@ static void bdrv_block_timer(void *opaque)
 
 void bdrv_io_limits_enable(BlockDriverState *bs)
 {
-    qemu_co_queue_init(&bs->throttled_reqs);
     bs->block_timer = qemu_new_timer_ns(vm_clock, bdrv_block_timer, bs);
     bs->io_limits_enabled = true;
 }
@@ -306,6 +305,7 @@ BlockDriverState *bdrv_new(const char *device_name)
     bdrv_iostatus_disable(bs);
     notifier_list_init(&bs->close_notifiers);
     notifier_with_return_list_init(&bs->before_write_notifiers);
+    qemu_co_queue_init(&bs->throttled_reqs);
 
     return bs;
 }
@@ -1428,6 +1428,35 @@ void bdrv_close_all(void)
     }
 }
 
+/* Check if any requests are in-flight (including throttled requests) */
+static bool bdrv_requests_pending(BlockDriverState *bs)
+{
+    if (!QLIST_EMPTY(&bs->tracked_requests)) {
+        return true;
+    }
+    if (!qemu_co_queue_empty(&bs->throttled_reqs)) {
+        return true;
+    }
+    if (bs->file && bdrv_requests_pending(bs->file)) {
+        return true;
+    }
+    if (bs->backing_hd && bdrv_requests_pending(bs->backing_hd)) {
+        return true;
+    }
+    return false;
+}
+
+static bool bdrv_requests_pending_all(void)
+{
+    BlockDriverState *bs;
+    QTAILQ_FOREACH(bs, &bdrv_states, list) {
+        if (bdrv_requests_pending(bs)) {
+            return true;
+        }
+    }
+    return false;
+}
+
 /*
  * Wait for pending requests to complete across all BlockDriverStates
  *
@@ -1442,12 +1471,11 @@ void bdrv_close_all(void)
  */
 void bdrv_drain_all(void)
 {
+    /* Always run first iteration so any pending completion BHs run */
+    bool busy = true;
     BlockDriverState *bs;
-    bool busy;
-
-    do {
-        busy = qemu_aio_wait();
 
+    while (busy) {
         /* FIXME: We do not have timer support here, so this is effectively
          * a busy wait.
          */
@@ -1456,12 +1484,9 @@ void bdrv_drain_all(void)
                 busy = true;
             }
         }
-    } while (busy);
 
-    /* If requests are still pending there is a bug somewhere */
-    QTAILQ_FOREACH(bs, &bdrv_states, list) {
-        assert(QLIST_EMPTY(&bs->tracked_requests));
-        assert(qemu_co_queue_empty(&bs->throttled_reqs));
+        busy = bdrv_requests_pending_all();
+        busy |= aio_poll(qemu_get_aio_context(), busy);
     }
 }
 
@@ -1606,11 +1631,11 @@ void bdrv_delete(BlockDriverState *bs)
     assert(!bs->job);
     assert(!bs->in_use);
 
+    bdrv_close(bs);
+
     /* remove from list, if necessary */
     bdrv_make_anon(bs);
 
-    bdrv_close(bs);
-
     g_free(bs);
 }
 
diff --git a/block/curl.c b/block/curl.c
index 82d39ff53f..e566855f76 100644
--- a/block/curl.c
+++ b/block/curl.c
@@ -86,7 +86,6 @@ typedef struct BDRVCURLState {
 
 static void curl_clean_state(CURLState *s);
 static void curl_multi_do(void *arg);
-static int curl_aio_flush(void *opaque);
 
 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
                         void *s, void *sp)
@@ -94,17 +93,16 @@ static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
     DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, fd);
     switch (action) {
         case CURL_POLL_IN:
-            qemu_aio_set_fd_handler(fd, curl_multi_do, NULL, curl_aio_flush, s);
+            qemu_aio_set_fd_handler(fd, curl_multi_do, NULL, s);
             break;
         case CURL_POLL_OUT:
-            qemu_aio_set_fd_handler(fd, NULL, curl_multi_do, curl_aio_flush, s);
+            qemu_aio_set_fd_handler(fd, NULL, curl_multi_do, s);
             break;
         case CURL_POLL_INOUT:
-            qemu_aio_set_fd_handler(fd, curl_multi_do, curl_multi_do,
-                                    curl_aio_flush, s);
+            qemu_aio_set_fd_handler(fd, curl_multi_do, curl_multi_do, s);
             break;
         case CURL_POLL_REMOVE:
-            qemu_aio_set_fd_handler(fd, NULL, NULL, NULL, NULL);
+            qemu_aio_set_fd_handler(fd, NULL, NULL, NULL);
             break;
     }
 
@@ -495,21 +493,6 @@ out_noclean:
     return -EINVAL;
 }
 
-static int curl_aio_flush(void *opaque)
-{
-    BDRVCURLState *s = opaque;
-    int i, j;
-
-    for (i=0; i < CURL_NUM_STATES; i++) {
-        for(j=0; j < CURL_NUM_ACB; j++) {
-            if (s->states[i].acb[j]) {
-                return 1;
-            }
-        }
-    }
-    return 0;
-}
-
 static void curl_aio_cancel(BlockDriverAIOCB *blockacb)
 {
     // Do we have to implement canceling? Seems to work without...
diff --git a/block/gluster.c b/block/gluster.c
index 645b7f12a5..46f36f8cd6 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -32,7 +32,6 @@ typedef struct BDRVGlusterState {
     struct glfs *glfs;
     int fds[2];
     struct glfs_fd *fd;
-    int qemu_aio_count;
     int event_reader_pos;
     GlusterAIOCB *event_acb;
 } BDRVGlusterState;
@@ -247,7 +246,6 @@ static void qemu_gluster_complete_aio(GlusterAIOCB *acb, BDRVGlusterState *s)
         ret = -EIO; /* Partial read/write - fail it */
     }
 
-    s->qemu_aio_count--;
     qemu_aio_release(acb);
     cb(opaque, ret);
     if (finished) {
@@ -275,13 +273,6 @@ static void qemu_gluster_aio_event_reader(void *opaque)
     } while (ret < 0 && errno == EINTR);
 }
 
-static int qemu_gluster_aio_flush_cb(void *opaque)
-{
-    BDRVGlusterState *s = opaque;
-
-    return (s->qemu_aio_count > 0);
-}
-
 /* TODO Convert to fine grained options */
 static QemuOptsList runtime_opts = {
     .name = "gluster",
@@ -348,7 +339,7 @@ static int qemu_gluster_open(BlockDriverState *bs,  QDict *options,
     }
     fcntl(s->fds[GLUSTER_FD_READ], F_SETFL, O_NONBLOCK);
     qemu_aio_set_fd_handler(s->fds[GLUSTER_FD_READ],
-        qemu_gluster_aio_event_reader, NULL, qemu_gluster_aio_flush_cb, s);
+        qemu_gluster_aio_event_reader, NULL, s);
 
 out:
     qemu_opts_del(opts);
@@ -445,11 +436,9 @@ static void gluster_finish_aiocb(struct glfs_fd *fd, ssize_t ret, void *arg)
         qemu_mutex_lock_iothread(); /* We are in gluster thread context */
         acb->common.cb(acb->common.opaque, -EIO);
         qemu_aio_release(acb);
-        s->qemu_aio_count--;
         close(s->fds[GLUSTER_FD_READ]);
         close(s->fds[GLUSTER_FD_WRITE]);
-        qemu_aio_set_fd_handler(s->fds[GLUSTER_FD_READ], NULL, NULL, NULL,
-            NULL);
+        qemu_aio_set_fd_handler(s->fds[GLUSTER_FD_READ], NULL, NULL, NULL);
         bs->drv = NULL; /* Make the disk inaccessible */
         qemu_mutex_unlock_iothread();
     }
@@ -467,7 +456,6 @@ static BlockDriverAIOCB *qemu_gluster_aio_rw(BlockDriverState *bs,
 
     offset = sector_num * BDRV_SECTOR_SIZE;
     size = nb_sectors * BDRV_SECTOR_SIZE;
-    s->qemu_aio_count++;
 
     acb = qemu_aio_get(&gluster_aiocb_info, bs, cb, opaque);
     acb->size = size;
@@ -488,7 +476,6 @@ static BlockDriverAIOCB *qemu_gluster_aio_rw(BlockDriverState *bs,
     return &acb->common;
 
 out:
-    s->qemu_aio_count--;
     qemu_aio_release(acb);
     return NULL;
 }
@@ -531,7 +518,6 @@ static BlockDriverAIOCB *qemu_gluster_aio_flush(BlockDriverState *bs,
     acb->size = 0;
     acb->ret = 0;
     acb->finished = NULL;
-    s->qemu_aio_count++;
 
     ret = glfs_fsync_async(s->fd, &gluster_finish_aiocb, acb);
     if (ret < 0) {
@@ -540,7 +526,6 @@ static BlockDriverAIOCB *qemu_gluster_aio_flush(BlockDriverState *bs,
     return &acb->common;
 
 out:
-    s->qemu_aio_count--;
     qemu_aio_release(acb);
     return NULL;
 }
@@ -563,7 +548,6 @@ static BlockDriverAIOCB *qemu_gluster_aio_discard(BlockDriverState *bs,
     acb->size = 0;
     acb->ret = 0;
     acb->finished = NULL;
-    s->qemu_aio_count++;
 
     ret = glfs_discard_async(s->fd, offset, size, &gluster_finish_aiocb, acb);
     if (ret < 0) {
@@ -572,7 +556,6 @@ static BlockDriverAIOCB *qemu_gluster_aio_discard(BlockDriverState *bs,
     return &acb->common;
 
 out:
-    s->qemu_aio_count--;
     qemu_aio_release(acb);
     return NULL;
 }
@@ -611,7 +594,7 @@ static void qemu_gluster_close(BlockDriverState *bs)
 
     close(s->fds[GLUSTER_FD_READ]);
     close(s->fds[GLUSTER_FD_WRITE]);
-    qemu_aio_set_fd_handler(s->fds[GLUSTER_FD_READ], NULL, NULL, NULL, NULL);
+    qemu_aio_set_fd_handler(s->fds[GLUSTER_FD_READ], NULL, NULL, NULL);
 
     if (s->fd) {
         glfs_close(s->fd);
diff --git a/block/iscsi.c b/block/iscsi.c
index e7c1c2b538..47a3adc9b5 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -146,13 +146,6 @@ static const AIOCBInfo iscsi_aiocb_info = {
 static void iscsi_process_read(void *arg);
 static void iscsi_process_write(void *arg);
 
-static int iscsi_process_flush(void *arg)
-{
-    IscsiLun *iscsilun = arg;
-
-    return iscsi_queue_length(iscsilun->iscsi) > 0;
-}
-
 static void
 iscsi_set_events(IscsiLun *iscsilun)
 {
@@ -166,7 +159,6 @@ iscsi_set_events(IscsiLun *iscsilun)
         qemu_aio_set_fd_handler(iscsi_get_fd(iscsi),
                       iscsi_process_read,
                       (ev & POLLOUT) ? iscsi_process_write : NULL,
-                      iscsi_process_flush,
                       iscsilun);
 
     }
@@ -1215,7 +1207,7 @@ static void iscsi_close(BlockDriverState *bs)
         qemu_del_timer(iscsilun->nop_timer);
         qemu_free_timer(iscsilun->nop_timer);
     }
-    qemu_aio_set_fd_handler(iscsi_get_fd(iscsi), NULL, NULL, NULL, NULL);
+    qemu_aio_set_fd_handler(iscsi_get_fd(iscsi), NULL, NULL, NULL);
     iscsi_destroy_context(iscsi);
     memset(iscsilun, 0, sizeof(IscsiLun));
 }
diff --git a/block/linux-aio.c b/block/linux-aio.c
index ee0f8d10c9..53434e2df5 100644
--- a/block/linux-aio.c
+++ b/block/linux-aio.c
@@ -39,7 +39,6 @@ struct qemu_laiocb {
 struct qemu_laio_state {
     io_context_t ctx;
     EventNotifier e;
-    int count;
 };
 
 static inline ssize_t io_event_ret(struct io_event *ev)
@@ -55,8 +54,6 @@ static void qemu_laio_process_completion(struct qemu_laio_state *s,
 {
     int ret;
 
-    s->count--;
-
     ret = laiocb->ret;
     if (ret != -ECANCELED) {
         if (ret == laiocb->nbytes) {
@@ -101,13 +98,6 @@ static void qemu_laio_completion_cb(EventNotifier *e)
     }
 }
 
-static int qemu_laio_flush_cb(EventNotifier *e)
-{
-    struct qemu_laio_state *s = container_of(e, struct qemu_laio_state, e);
-
-    return (s->count > 0) ? 1 : 0;
-}
-
 static void laio_cancel(BlockDriverAIOCB *blockacb)
 {
     struct qemu_laiocb *laiocb = (struct qemu_laiocb *)blockacb;
@@ -177,14 +167,11 @@ BlockDriverAIOCB *laio_submit(BlockDriverState *bs, void *aio_ctx, int fd,
         goto out_free_aiocb;
     }
     io_set_eventfd(&laiocb->iocb, event_notifier_get_fd(&s->e));
-    s->count++;
 
     if (io_submit(s->ctx, 1, &iocbs) < 0)
-        goto out_dec_count;
+        goto out_free_aiocb;
     return &laiocb->common;
 
-out_dec_count:
-    s->count--;
 out_free_aiocb:
     qemu_aio_release(laiocb);
     return NULL;
@@ -203,8 +190,7 @@ void *laio_init(void)
         goto out_close_efd;
     }
 
-    qemu_aio_set_event_notifier(&s->e, qemu_laio_completion_cb,
-                                qemu_laio_flush_cb);
+    qemu_aio_set_event_notifier(&s->e, qemu_laio_completion_cb);
 
     return s;
 
diff --git a/block/nbd.c b/block/nbd.c
index 9c480b8f26..691066f726 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -279,13 +279,6 @@ static void nbd_coroutine_start(BDRVNBDState *s, struct nbd_request *request)
     request->handle = INDEX_TO_HANDLE(s, i);
 }
 
-static int nbd_have_request(void *opaque)
-{
-    BDRVNBDState *s = opaque;
-
-    return s->in_flight > 0;
-}
-
 static void nbd_reply_ready(void *opaque)
 {
     BDRVNBDState *s = opaque;
@@ -341,8 +334,7 @@ static int nbd_co_send_request(BDRVNBDState *s, struct nbd_request *request,
 
     qemu_co_mutex_lock(&s->send_mutex);
     s->send_coroutine = qemu_coroutine_self();
-    qemu_aio_set_fd_handler(s->sock, nbd_reply_ready, nbd_restart_write,
-                            nbd_have_request, s);
+    qemu_aio_set_fd_handler(s->sock, nbd_reply_ready, nbd_restart_write, s);
     if (qiov) {
         if (!s->is_unix) {
             socket_set_cork(s->sock, 1);
@@ -361,8 +353,7 @@ static int nbd_co_send_request(BDRVNBDState *s, struct nbd_request *request,
     } else {
         rc = nbd_send_request(s->sock, request);
     }
-    qemu_aio_set_fd_handler(s->sock, nbd_reply_ready, NULL,
-                            nbd_have_request, s);
+    qemu_aio_set_fd_handler(s->sock, nbd_reply_ready, NULL, s);
     s->send_coroutine = NULL;
     qemu_co_mutex_unlock(&s->send_mutex);
     return rc;
@@ -438,8 +429,7 @@ static int nbd_establish_connection(BlockDriverState *bs)
     /* Now that we're connected, set the socket to be non-blocking and
      * kick the reply mechanism.  */
     qemu_set_nonblock(sock);
-    qemu_aio_set_fd_handler(sock, nbd_reply_ready, NULL,
-                            nbd_have_request, s);
+    qemu_aio_set_fd_handler(sock, nbd_reply_ready, NULL, s);
 
     s->sock = sock;
     s->size = size;
@@ -459,7 +449,7 @@ static void nbd_teardown_connection(BlockDriverState *bs)
     request.len = 0;
     nbd_send_request(s->sock, &request);
 
-    qemu_aio_set_fd_handler(s->sock, NULL, NULL, NULL, NULL);
+    qemu_aio_set_fd_handler(s->sock, NULL, NULL, NULL);
     closesocket(s->sock);
 }
 
diff --git a/block/rbd.c b/block/rbd.c
index cb71751218..e798e19f81 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -100,7 +100,6 @@ typedef struct BDRVRBDState {
     rados_ioctx_t io_ctx;
     rbd_image_t image;
     char name[RBD_MAX_IMAGE_NAME_SIZE];
-    int qemu_aio_count;
     char *snap;
     int event_reader_pos;
     RADOSCB *event_rcb;
@@ -428,19 +427,11 @@ static void qemu_rbd_aio_event_reader(void *opaque)
             if (s->event_reader_pos == sizeof(s->event_rcb)) {
                 s->event_reader_pos = 0;
                 qemu_rbd_complete_aio(s->event_rcb);
-                s->qemu_aio_count--;
             }
         }
     } while (ret < 0 && errno == EINTR);
 }
 
-static int qemu_rbd_aio_flush_cb(void *opaque)
-{
-    BDRVRBDState *s = opaque;
-
-    return (s->qemu_aio_count > 0);
-}
-
 /* TODO Convert to fine grained options */
 static QemuOptsList runtime_opts = {
     .name = "rbd",
@@ -554,7 +545,7 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags)
     fcntl(s->fds[0], F_SETFL, O_NONBLOCK);
     fcntl(s->fds[1], F_SETFL, O_NONBLOCK);
     qemu_aio_set_fd_handler(s->fds[RBD_FD_READ], qemu_rbd_aio_event_reader,
-                            NULL, qemu_rbd_aio_flush_cb, s);
+                            NULL, s);
 
 
     qemu_opts_del(opts);
@@ -578,7 +569,7 @@ static void qemu_rbd_close(BlockDriverState *bs)
 
     close(s->fds[0]);
     close(s->fds[1]);
-    qemu_aio_set_fd_handler(s->fds[RBD_FD_READ], NULL, NULL, NULL, NULL);
+    qemu_aio_set_fd_handler(s->fds[RBD_FD_READ], NULL, NULL, NULL);
 
     rbd_close(s->image);
     rados_ioctx_destroy(s->io_ctx);
@@ -741,8 +732,6 @@ static BlockDriverAIOCB *rbd_start_aio(BlockDriverState *bs,
     off = sector_num * BDRV_SECTOR_SIZE;
     size = nb_sectors * BDRV_SECTOR_SIZE;
 
-    s->qemu_aio_count++; /* All the RADOSCB */
-
     rcb = g_malloc(sizeof(RADOSCB));
     rcb->done = 0;
     rcb->acb = acb;
@@ -779,7 +768,6 @@ static BlockDriverAIOCB *rbd_start_aio(BlockDriverState *bs,
 
 failed:
     g_free(rcb);
-    s->qemu_aio_count--;
     qemu_aio_release(acb);
     return NULL;
 }
diff --git a/block/sheepdog.c b/block/sheepdog.c
index afe053376c..1ad4d070e7 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -509,13 +509,6 @@ static void restart_co_req(void *opaque)
     qemu_coroutine_enter(co, NULL);
 }
 
-static int have_co_req(void *opaque)
-{
-    /* this handler is set only when there is a pending request, so
-     * always returns 1. */
-    return 1;
-}
-
 typedef struct SheepdogReqCo {
     int sockfd;
     SheepdogReq *hdr;
@@ -538,14 +531,14 @@ static coroutine_fn void do_co_req(void *opaque)
     unsigned int *rlen = srco->rlen;
 
     co = qemu_coroutine_self();
-    qemu_aio_set_fd_handler(sockfd, NULL, restart_co_req, have_co_req, co);
+    qemu_aio_set_fd_handler(sockfd, NULL, restart_co_req, co);
 
     ret = send_co_req(sockfd, hdr, data, wlen);
     if (ret < 0) {
         goto out;
     }
 
-    qemu_aio_set_fd_handler(sockfd, restart_co_req, NULL, have_co_req, co);
+    qemu_aio_set_fd_handler(sockfd, restart_co_req, NULL, co);
 
     ret = qemu_co_recv(sockfd, hdr, sizeof(*hdr));
     if (ret < sizeof(*hdr)) {
@@ -570,7 +563,7 @@ static coroutine_fn void do_co_req(void *opaque)
 out:
     /* there is at most one request for this sockfd, so it is safe to
      * set each handler to NULL. */
-    qemu_aio_set_fd_handler(sockfd, NULL, NULL, NULL, NULL);
+    qemu_aio_set_fd_handler(sockfd, NULL, NULL, NULL);
 
     srco->ret = ret;
     srco->finished = true;
@@ -796,14 +789,6 @@ static void co_write_request(void *opaque)
     qemu_coroutine_enter(s->co_send, NULL);
 }
 
-static int aio_flush_request(void *opaque)
-{
-    BDRVSheepdogState *s = opaque;
-
-    return !QLIST_EMPTY(&s->inflight_aio_head) ||
-        !QLIST_EMPTY(&s->pending_aio_head);
-}
-
 /*
  * Return a socket discriptor to read/write objects.
  *
@@ -819,7 +804,7 @@ static int get_sheep_fd(BDRVSheepdogState *s)
         return fd;
     }
 
-    qemu_aio_set_fd_handler(fd, co_read_response, NULL, aio_flush_request, s);
+    qemu_aio_set_fd_handler(fd, co_read_response, NULL, s);
     return fd;
 }
 
@@ -1069,8 +1054,7 @@ static int coroutine_fn add_aio_request(BDRVSheepdogState *s, AIOReq *aio_req,
 
     qemu_co_mutex_lock(&s->lock);
     s->co_send = qemu_coroutine_self();
-    qemu_aio_set_fd_handler(s->fd, co_read_response, co_write_request,
-                            aio_flush_request, s);
+    qemu_aio_set_fd_handler(s->fd, co_read_response, co_write_request, s);
     socket_set_cork(s->fd, 1);
 
     /* send a header */
@@ -1091,8 +1075,7 @@ static int coroutine_fn add_aio_request(BDRVSheepdogState *s, AIOReq *aio_req,
     }
 
     socket_set_cork(s->fd, 0);
-    qemu_aio_set_fd_handler(s->fd, co_read_response, NULL,
-                            aio_flush_request, s);
+    qemu_aio_set_fd_handler(s->fd, co_read_response, NULL, s);
     qemu_co_mutex_unlock(&s->lock);
 
     return 0;
@@ -1350,7 +1333,7 @@ static int sd_open(BlockDriverState *bs, QDict *options, int flags)
     g_free(buf);
     return 0;
 out:
-    qemu_aio_set_fd_handler(s->fd, NULL, NULL, NULL, NULL);
+    qemu_aio_set_fd_handler(s->fd, NULL, NULL, NULL);
     if (s->fd >= 0) {
         closesocket(s->fd);
     }
@@ -1578,7 +1561,7 @@ static void sd_close(BlockDriverState *bs)
         error_report("%s, %s", sd_strerror(rsp->result), s->name);
     }
 
-    qemu_aio_set_fd_handler(s->fd, NULL, NULL, NULL, NULL);
+    qemu_aio_set_fd_handler(s->fd, NULL, NULL, NULL);
     closesocket(s->fd);
     g_free(s->host_spec);
 }
diff --git a/block/ssh.c b/block/ssh.c
index d7e7bf8dd2..27691b4ad5 100644
--- a/block/ssh.c
+++ b/block/ssh.c
@@ -740,14 +740,6 @@ static void restart_coroutine(void *opaque)
     qemu_coroutine_enter(co, NULL);
 }
 
-/* Always true because when we have called set_fd_handler there is
- * always a request being processed.
- */
-static int return_true(void *opaque)
-{
-    return 1;
-}
-
 static coroutine_fn void set_fd_handler(BDRVSSHState *s)
 {
     int r;
@@ -766,13 +758,13 @@ static coroutine_fn void set_fd_handler(BDRVSSHState *s)
     DPRINTF("s->sock=%d rd_handler=%p wr_handler=%p", s->sock,
             rd_handler, wr_handler);
 
-    qemu_aio_set_fd_handler(s->sock, rd_handler, wr_handler, return_true, co);
+    qemu_aio_set_fd_handler(s->sock, rd_handler, wr_handler, co);
 }
 
 static coroutine_fn void clear_fd_handler(BDRVSSHState *s)
 {
     DPRINTF("s->sock=%d", s->sock);
-    qemu_aio_set_fd_handler(s->sock, NULL, NULL, NULL, NULL);
+    qemu_aio_set_fd_handler(s->sock, NULL, NULL, NULL);
 }
 
 /* A non-blocking call returned EAGAIN, so yield, ensuring the
diff --git a/block/stream.c b/block/stream.c
index 7fe9e486bf..db49b4d85f 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -57,6 +57,11 @@ static void close_unused_images(BlockDriverState *top, BlockDriverState *base,
     BlockDriverState *intermediate;
     intermediate = top->backing_hd;
 
+    /* Must assign before bdrv_delete() to prevent traversing dangling pointer
+     * while we delete backing image instances.
+     */
+    top->backing_hd = base;
+
     while (intermediate) {
         BlockDriverState *unused;
 
@@ -70,7 +75,6 @@ static void close_unused_images(BlockDriverState *top, BlockDriverState *base,
         unused->backing_hd = NULL;
         bdrv_delete(unused);
     }
-    top->backing_hd = base;
 }
 
 static void coroutine_fn stream_run(void *opaque)
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index 411becc06e..5a96ccd416 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -261,11 +261,6 @@ static int process_request(IOQueue *ioq, struct iovec iov[],
     }
 }
 
-static int flush_true(EventNotifier *e)
-{
-    return true;
-}
-
 static void handle_notify(EventNotifier *e)
 {
     VirtIOBlockDataPlane *s = container_of(e, VirtIOBlockDataPlane,
@@ -345,14 +340,6 @@ static void handle_notify(EventNotifier *e)
     }
 }
 
-static int flush_io(EventNotifier *e)
-{
-    VirtIOBlockDataPlane *s = container_of(e, VirtIOBlockDataPlane,
-                                           io_notifier);
-
-    return s->num_reqs > 0;
-}
-
 static void handle_io(EventNotifier *e)
 {
     VirtIOBlockDataPlane *s = container_of(e, VirtIOBlockDataPlane,
@@ -376,9 +363,9 @@ static void *data_plane_thread(void *opaque)
 {
     VirtIOBlockDataPlane *s = opaque;
 
-    do {
+    while (!s->stopping || s->num_reqs > 0) {
         aio_poll(s->ctx, true);
-    } while (!s->stopping || s->num_reqs > 0);
+    }
     return NULL;
 }
 
@@ -485,7 +472,7 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
         exit(1);
     }
     s->host_notifier = *virtio_queue_get_host_notifier(vq);
-    aio_set_event_notifier(s->ctx, &s->host_notifier, handle_notify, flush_true);
+    aio_set_event_notifier(s->ctx, &s->host_notifier, handle_notify);
 
     /* Set up ioqueue */
     ioq_init(&s->ioqueue, s->fd, REQ_MAX);
@@ -493,7 +480,7 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
         ioq_put_iocb(&s->ioqueue, &s->requests[i].iocb);
     }
     s->io_notifier = *ioq_get_notifier(&s->ioqueue);
-    aio_set_event_notifier(s->ctx, &s->io_notifier, handle_io, flush_io);
+    aio_set_event_notifier(s->ctx, &s->io_notifier, handle_io);
 
     s->started = true;
     trace_virtio_blk_data_plane_start(s);
@@ -525,10 +512,10 @@ void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s)
         qemu_thread_join(&s->thread);
     }
 
-    aio_set_event_notifier(s->ctx, &s->io_notifier, NULL, NULL);
+    aio_set_event_notifier(s->ctx, &s->io_notifier, NULL);
     ioq_cleanup(&s->ioqueue);
 
-    aio_set_event_notifier(s->ctx, &s->host_notifier, NULL, NULL);
+    aio_set_event_notifier(s->ctx, &s->host_notifier, NULL);
     k->set_host_notifier(qbus->parent, 0, false);
 
     aio_context_unref(s->ctx);
diff --git a/include/block/aio.h b/include/block/aio.h
index cc77771c46..5743bf1ba0 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -74,9 +74,6 @@ typedef struct AioContext {
     struct ThreadPool *thread_pool;
 } AioContext;
 
-/* Returns 1 if there are still outstanding AIO requests; 0 otherwise */
-typedef int (AioFlushEventNotifierHandler)(EventNotifier *e);
-
 /**
  * aio_context_new: Allocate a new AioContext.
  *
@@ -198,9 +195,6 @@ bool aio_pending(AioContext *ctx);
 bool aio_poll(AioContext *ctx, bool blocking);
 
 #ifdef CONFIG_POSIX
-/* Returns 1 if there are still outstanding AIO requests; 0 otherwise */
-typedef int (AioFlushHandler)(void *opaque);
-
 /* Register a file descriptor and associated callbacks.  Behaves very similarly
  * to qemu_set_fd_handler2.  Unlike qemu_set_fd_handler2, these callbacks will
  * be invoked when using qemu_aio_wait().
@@ -212,7 +206,6 @@ void aio_set_fd_handler(AioContext *ctx,
                         int fd,
                         IOHandler *io_read,
                         IOHandler *io_write,
-                        AioFlushHandler *io_flush,
                         void *opaque);
 #endif
 
@@ -225,8 +218,7 @@ void aio_set_fd_handler(AioContext *ctx,
  */
 void aio_set_event_notifier(AioContext *ctx,
                             EventNotifier *notifier,
-                            EventNotifierHandler *io_read,
-                            AioFlushEventNotifierHandler *io_flush);
+                            EventNotifierHandler *io_read);
 
 /* Return a GSource that lets the main loop poll the file descriptors attached
  * to this AioContext.
@@ -240,14 +232,12 @@ struct ThreadPool *aio_get_thread_pool(AioContext *ctx);
 
 bool qemu_aio_wait(void);
 void qemu_aio_set_event_notifier(EventNotifier *notifier,
-                                 EventNotifierHandler *io_read,
-                                 AioFlushEventNotifierHandler *io_flush);
+                                 EventNotifierHandler *io_read);
 
 #ifdef CONFIG_POSIX
 void qemu_aio_set_fd_handler(int fd,
                              IOHandler *io_read,
                              IOHandler *io_write,
-                             AioFlushHandler *io_flush,
                              void *opaque);
 #endif
 
diff --git a/main-loop.c b/main-loop.c
index a44fff6e9a..2d9774ef75 100644
--- a/main-loop.c
+++ b/main-loop.c
@@ -489,17 +489,14 @@ bool qemu_aio_wait(void)
 void qemu_aio_set_fd_handler(int fd,
                              IOHandler *io_read,
                              IOHandler *io_write,
-                             AioFlushHandler *io_flush,
                              void *opaque)
 {
-    aio_set_fd_handler(qemu_aio_context, fd, io_read, io_write, io_flush,
-                       opaque);
+    aio_set_fd_handler(qemu_aio_context, fd, io_read, io_write, opaque);
 }
 #endif
 
 void qemu_aio_set_event_notifier(EventNotifier *notifier,
-                                 EventNotifierHandler *io_read,
-                                 AioFlushEventNotifierHandler *io_flush)
+                                 EventNotifierHandler *io_read)
 {
-    aio_set_event_notifier(qemu_aio_context, notifier, io_read, io_flush);
+    aio_set_event_notifier(qemu_aio_context, notifier, io_read);
 }
diff --git a/tests/test-aio.c b/tests/test-aio.c
index c1738706cd..1ab5637d95 100644
--- a/tests/test-aio.c
+++ b/tests/test-aio.c
@@ -15,6 +15,13 @@
 
 AioContext *ctx;
 
+typedef struct {
+    EventNotifier e;
+    int n;
+    int active;
+    bool auto_set;
+} EventNotifierTestData;
+
 /* Wait until there are no more BHs or AIO requests */
 static void wait_for_aio(void)
 {
@@ -23,6 +30,14 @@ static void wait_for_aio(void)
     }
 }
 
+/* Wait until event notifier becomes inactive */
+static void wait_until_inactive(EventNotifierTestData *data)
+{
+    while (data->active > 0) {
+        aio_poll(ctx, true);
+    }
+}
+
 /* Simple callbacks for testing.  */
 
 typedef struct {
@@ -50,19 +65,6 @@ static void bh_delete_cb(void *opaque)
     }
 }
 
-typedef struct {
-    EventNotifier e;
-    int n;
-    int active;
-    bool auto_set;
-} EventNotifierTestData;
-
-static int event_active_cb(EventNotifier *e)
-{
-    EventNotifierTestData *data = container_of(e, EventNotifierTestData, e);
-    return data->active > 0;
-}
-
 static void event_ready_cb(EventNotifier *e)
 {
     EventNotifierTestData *data = container_of(e, EventNotifierTestData, e);
@@ -231,11 +233,11 @@ static void test_set_event_notifier(void)
 {
     EventNotifierTestData data = { .n = 0, .active = 0 };
     event_notifier_init(&data.e, false);
-    aio_set_event_notifier(ctx, &data.e, event_ready_cb, event_active_cb);
+    aio_set_event_notifier(ctx, &data.e, event_ready_cb);
     g_assert(!aio_poll(ctx, false));
     g_assert_cmpint(data.n, ==, 0);
 
-    aio_set_event_notifier(ctx, &data.e, NULL, NULL);
+    aio_set_event_notifier(ctx, &data.e, NULL);
     g_assert(!aio_poll(ctx, false));
     g_assert_cmpint(data.n, ==, 0);
     event_notifier_cleanup(&data.e);
@@ -245,8 +247,8 @@ static void test_wait_event_notifier(void)
 {
     EventNotifierTestData data = { .n = 0, .active = 1 };
     event_notifier_init(&data.e, false);
-    aio_set_event_notifier(ctx, &data.e, event_ready_cb, event_active_cb);
-    g_assert(aio_poll(ctx, false));
+    aio_set_event_notifier(ctx, &data.e, event_ready_cb);
+    g_assert(!aio_poll(ctx, false));
     g_assert_cmpint(data.n, ==, 0);
     g_assert_cmpint(data.active, ==, 1);
 
@@ -259,7 +261,7 @@ static void test_wait_event_notifier(void)
     g_assert_cmpint(data.n, ==, 1);
     g_assert_cmpint(data.active, ==, 0);
 
-    aio_set_event_notifier(ctx, &data.e, NULL, NULL);
+    aio_set_event_notifier(ctx, &data.e, NULL);
     g_assert(!aio_poll(ctx, false));
     g_assert_cmpint(data.n, ==, 1);
 
@@ -270,8 +272,8 @@ static void test_flush_event_notifier(void)
 {
     EventNotifierTestData data = { .n = 0, .active = 10, .auto_set = true };
     event_notifier_init(&data.e, false);
-    aio_set_event_notifier(ctx, &data.e, event_ready_cb, event_active_cb);
-    g_assert(aio_poll(ctx, false));
+    aio_set_event_notifier(ctx, &data.e, event_ready_cb);
+    g_assert(!aio_poll(ctx, false));
     g_assert_cmpint(data.n, ==, 0);
     g_assert_cmpint(data.active, ==, 10);
 
@@ -281,12 +283,12 @@ static void test_flush_event_notifier(void)
     g_assert_cmpint(data.active, ==, 9);
     g_assert(aio_poll(ctx, false));
 
-    wait_for_aio();
+    wait_until_inactive(&data);
     g_assert_cmpint(data.n, ==, 10);
     g_assert_cmpint(data.active, ==, 0);
     g_assert(!aio_poll(ctx, false));
 
-    aio_set_event_notifier(ctx, &data.e, NULL, NULL);
+    aio_set_event_notifier(ctx, &data.e, NULL);
     g_assert(!aio_poll(ctx, false));
     event_notifier_cleanup(&data.e);
 }
@@ -297,7 +299,7 @@ static void test_wait_event_notifier_noflush(void)
     EventNotifierTestData dummy = { .n = 0, .active = 1 };
 
     event_notifier_init(&data.e, false);
-    aio_set_event_notifier(ctx, &data.e, event_ready_cb, NULL);
+    aio_set_event_notifier(ctx, &data.e, event_ready_cb);
 
     g_assert(!aio_poll(ctx, false));
     g_assert_cmpint(data.n, ==, 0);
@@ -305,35 +307,35 @@ static void test_wait_event_notifier_noflush(void)
     /* Until there is an active descriptor, aio_poll may or may not call
      * event_ready_cb.  Still, it must not block.  */
     event_notifier_set(&data.e);
-    g_assert(!aio_poll(ctx, true));
+    g_assert(aio_poll(ctx, true));
     data.n = 0;
 
     /* An active event notifier forces aio_poll to look at EventNotifiers.  */
     event_notifier_init(&dummy.e, false);
-    aio_set_event_notifier(ctx, &dummy.e, event_ready_cb, event_active_cb);
+    aio_set_event_notifier(ctx, &dummy.e, event_ready_cb);
 
     event_notifier_set(&data.e);
     g_assert(aio_poll(ctx, false));
     g_assert_cmpint(data.n, ==, 1);
-    g_assert(aio_poll(ctx, false));
+    g_assert(!aio_poll(ctx, false));
     g_assert_cmpint(data.n, ==, 1);
 
     event_notifier_set(&data.e);
     g_assert(aio_poll(ctx, false));
     g_assert_cmpint(data.n, ==, 2);
-    g_assert(aio_poll(ctx, false));
+    g_assert(!aio_poll(ctx, false));
     g_assert_cmpint(data.n, ==, 2);
 
     event_notifier_set(&dummy.e);
-    wait_for_aio();
+    wait_until_inactive(&dummy);
     g_assert_cmpint(data.n, ==, 2);
     g_assert_cmpint(dummy.n, ==, 1);
     g_assert_cmpint(dummy.active, ==, 0);
 
-    aio_set_event_notifier(ctx, &dummy.e, NULL, NULL);
+    aio_set_event_notifier(ctx, &dummy.e, NULL);
     event_notifier_cleanup(&dummy.e);
 
-    aio_set_event_notifier(ctx, &data.e, NULL, NULL);
+    aio_set_event_notifier(ctx, &data.e, NULL);
     g_assert(!aio_poll(ctx, false));
     g_assert_cmpint(data.n, ==, 2);
 
@@ -513,11 +515,11 @@ static void test_source_set_event_notifier(void)
 {
     EventNotifierTestData data = { .n = 0, .active = 0 };
     event_notifier_init(&data.e, false);
-    aio_set_event_notifier(ctx, &data.e, event_ready_cb, event_active_cb);
+    aio_set_event_notifier(ctx, &data.e, event_ready_cb);
     while (g_main_context_iteration(NULL, false));
     g_assert_cmpint(data.n, ==, 0);
 
-    aio_set_event_notifier(ctx, &data.e, NULL, NULL);
+    aio_set_event_notifier(ctx, &data.e, NULL);
     while (g_main_context_iteration(NULL, false));
     g_assert_cmpint(data.n, ==, 0);
     event_notifier_cleanup(&data.e);
@@ -527,7 +529,7 @@ static void test_source_wait_event_notifier(void)
 {
     EventNotifierTestData data = { .n = 0, .active = 1 };
     event_notifier_init(&data.e, false);
-    aio_set_event_notifier(ctx, &data.e, event_ready_cb, event_active_cb);
+    aio_set_event_notifier(ctx, &data.e, event_ready_cb);
     g_assert(g_main_context_iteration(NULL, false));
     g_assert_cmpint(data.n, ==, 0);
     g_assert_cmpint(data.active, ==, 1);
@@ -541,7 +543,7 @@ static void test_source_wait_event_notifier(void)
     g_assert_cmpint(data.n, ==, 1);
     g_assert_cmpint(data.active, ==, 0);
 
-    aio_set_event_notifier(ctx, &data.e, NULL, NULL);
+    aio_set_event_notifier(ctx, &data.e, NULL);
     while (g_main_context_iteration(NULL, false));
     g_assert_cmpint(data.n, ==, 1);
 
@@ -552,7 +554,7 @@ static void test_source_flush_event_notifier(void)
 {
     EventNotifierTestData data = { .n = 0, .active = 10, .auto_set = true };
     event_notifier_init(&data.e, false);
-    aio_set_event_notifier(ctx, &data.e, event_ready_cb, event_active_cb);
+    aio_set_event_notifier(ctx, &data.e, event_ready_cb);
     g_assert(g_main_context_iteration(NULL, false));
     g_assert_cmpint(data.n, ==, 0);
     g_assert_cmpint(data.active, ==, 10);
@@ -568,7 +570,7 @@ static void test_source_flush_event_notifier(void)
     g_assert_cmpint(data.active, ==, 0);
     g_assert(!g_main_context_iteration(NULL, false));
 
-    aio_set_event_notifier(ctx, &data.e, NULL, NULL);
+    aio_set_event_notifier(ctx, &data.e, NULL);
     while (g_main_context_iteration(NULL, false));
     event_notifier_cleanup(&data.e);
 }
@@ -579,7 +581,7 @@ static void test_source_wait_event_notifier_noflush(void)
     EventNotifierTestData dummy = { .n = 0, .active = 1 };
 
     event_notifier_init(&data.e, false);
-    aio_set_event_notifier(ctx, &data.e, event_ready_cb, NULL);
+    aio_set_event_notifier(ctx, &data.e, event_ready_cb);
 
     while (g_main_context_iteration(NULL, false));
     g_assert_cmpint(data.n, ==, 0);
@@ -592,7 +594,7 @@ static void test_source_wait_event_notifier_noflush(void)
 
     /* An active event notifier forces aio_poll to look at EventNotifiers.  */
     event_notifier_init(&dummy.e, false);
-    aio_set_event_notifier(ctx, &dummy.e, event_ready_cb, event_active_cb);
+    aio_set_event_notifier(ctx, &dummy.e, event_ready_cb);
 
     event_notifier_set(&data.e);
     g_assert(g_main_context_iteration(NULL, false));
@@ -612,10 +614,10 @@ static void test_source_wait_event_notifier_noflush(void)
     g_assert_cmpint(dummy.n, ==, 1);
     g_assert_cmpint(dummy.active, ==, 0);
 
-    aio_set_event_notifier(ctx, &dummy.e, NULL, NULL);
+    aio_set_event_notifier(ctx, &dummy.e, NULL);
     event_notifier_cleanup(&dummy.e);
 
-    aio_set_event_notifier(ctx, &data.e, NULL, NULL);
+    aio_set_event_notifier(ctx, &data.e, NULL);
     while (g_main_context_iteration(NULL, false));
     g_assert_cmpint(data.n, ==, 2);
 
diff --git a/tests/test-thread-pool.c b/tests/test-thread-pool.c
index b62338f375..8188d1a69d 100644
--- a/tests/test-thread-pool.c
+++ b/tests/test-thread-pool.c
@@ -40,19 +40,13 @@ static void done_cb(void *opaque, int ret)
     active--;
 }
 
-/* Wait until all aio and bh activity has finished */
-static void qemu_aio_wait_all(void)
-{
-    while (aio_poll(ctx, true)) {
-        /* Do nothing */
-    }
-}
-
 static void test_submit(void)
 {
     WorkerTestData data = { .n = 0 };
     thread_pool_submit(pool, worker_cb, &data);
-    qemu_aio_wait_all();
+    while (data.n == 0) {
+        aio_poll(ctx, true);
+    }
     g_assert_cmpint(data.n, ==, 1);
 }
 
@@ -65,7 +59,9 @@ static void test_submit_aio(void)
     /* The callbacks are not called until after the first wait.  */
     active = 1;
     g_assert_cmpint(data.ret, ==, -EINPROGRESS);
-    qemu_aio_wait_all();
+    while (data.ret == -EINPROGRESS) {
+        aio_poll(ctx, true);
+    }
     g_assert_cmpint(active, ==, 0);
     g_assert_cmpint(data.n, ==, 1);
     g_assert_cmpint(data.ret, ==, 0);
@@ -103,7 +99,9 @@ static void test_submit_co(void)
 
     /* qemu_aio_wait_all will execute the rest of the coroutine.  */
 
-    qemu_aio_wait_all();
+    while (data.ret == -EINPROGRESS) {
+        aio_poll(ctx, true);
+    }
 
     /* Back here after the coroutine has finished.  */
 
@@ -187,7 +185,9 @@ static void test_cancel(void)
     }
 
     /* Finish execution and execute any remaining callbacks.  */
-    qemu_aio_wait_all();
+    while (active > 0) {
+        aio_poll(ctx, true);
+    }
     g_assert_cmpint(active, ==, 0);
     for (i = 0; i < 100; i++) {
         if (data[i].n == 3) {
diff --git a/thread-pool.c b/thread-pool.c
index 0ebd4c2964..5025567817 100644
--- a/thread-pool.c
+++ b/thread-pool.c
@@ -197,12 +197,6 @@ restart:
     }
 }
 
-static int thread_pool_active(EventNotifier *notifier)
-{
-    ThreadPool *pool = container_of(notifier, ThreadPool, notifier);
-    return !QLIST_EMPTY(&pool->head);
-}
-
 static void thread_pool_cancel(BlockDriverAIOCB *acb)
 {
     ThreadPoolElement *elem = (ThreadPoolElement *)acb;
@@ -309,8 +303,7 @@ static void thread_pool_init_one(ThreadPool *pool, AioContext *ctx)
     QLIST_INIT(&pool->head);
     QTAILQ_INIT(&pool->request_list);
 
-    aio_set_event_notifier(ctx, &pool->notifier, event_notifier_ready,
-                           thread_pool_active);
+    aio_set_event_notifier(ctx, &pool->notifier, event_notifier_ready);
 }
 
 ThreadPool *thread_pool_new(AioContext *ctx)
@@ -344,7 +337,7 @@ void thread_pool_free(ThreadPool *pool)
 
     qemu_mutex_unlock(&pool->lock);
 
-    aio_set_event_notifier(pool->ctx, &pool->notifier, NULL, NULL);
+    aio_set_event_notifier(pool->ctx, &pool->notifier, NULL);
     qemu_sem_destroy(&pool->sem);
     qemu_cond_destroy(&pool->check_cancel);
     qemu_cond_destroy(&pool->worker_stopped);