aio: remove aio_disable_external() API

All callers now pass is_external=false to aio_set_fd_handler() and
aio_set_event_notifier(). The aio_disable_external() API that
temporarily disables fd handlers that were registered is_external=true
is therefore dead code.

Remove aio_disable_external(), aio_enable_external(), and the
is_external arguments to aio_set_fd_handler() and
aio_set_event_notifier().

The entire test-fdmon-epoll test is removed because its sole purpose was
testing aio_disable_external().

Parts of this patch were generated using the following coccinelle
(https://coccinelle.lip6.fr/) semantic patch:

  @@
  expression ctx, fd, is_external, io_read, io_write, io_poll, io_poll_ready, opaque;
  @@
  - aio_set_fd_handler(ctx, fd, is_external, io_read, io_write, io_poll, io_poll_ready, opaque)
  + aio_set_fd_handler(ctx, fd, io_read, io_write, io_poll, io_poll_ready, opaque)

  @@
  expression ctx, notifier, is_external, io_read, io_poll, io_poll_ready;
  @@
  - aio_set_event_notifier(ctx, notifier, is_external, io_read, io_poll, io_poll_ready)
  + aio_set_event_notifier(ctx, notifier, io_read, io_poll, io_poll_ready)

Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230516190238.8401-21-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

10 files changed, 20 insertions, 58 deletions

diff --git a/util/aio-posix.c b/util/aio-posix.c
index 34bc2a6..7f2c997 100644
--- a/util/aio-posix.c
+++ b/util/aio-posix.c
@@ -99,7 +99,6 @@ static bool aio_remove_fd_handler(AioContext *ctx, AioHandler *node)
 
 void aio_set_fd_handler(AioContext *ctx,
                         int fd,
-                        bool is_external,
                         IOHandler *io_read,
                         IOHandler *io_write,
                         AioPollFn *io_poll,
@@ -144,7 +143,6 @@ void aio_set_fd_handler(AioContext *ctx,
         new_node->io_poll = io_poll;
         new_node->io_poll_ready = io_poll_ready;
         new_node->opaque = opaque;
-        new_node->is_external = is_external;
 
         if (is_new) {
             new_node->pfd.fd = fd;
@@ -196,12 +194,11 @@ static void aio_set_fd_poll(AioContext *ctx, int fd,
 
 void aio_set_event_notifier(AioContext *ctx,
                             EventNotifier *notifier,
-                            bool is_external,
                             EventNotifierHandler *io_read,
                             AioPollFn *io_poll,
                             EventNotifierHandler *io_poll_ready)
 {
-    aio_set_fd_handler(ctx, event_notifier_get_fd(notifier), is_external,
+    aio_set_fd_handler(ctx, event_notifier_get_fd(notifier),
                        (IOHandler *)io_read, NULL, io_poll,
                        (IOHandler *)io_poll_ready, notifier);
 }
@@ -285,13 +282,11 @@ bool aio_pending(AioContext *ctx)
 
         /* TODO should this check poll ready? */
         revents = node->pfd.revents & node->pfd.events;
-        if (revents & (G_IO_IN | G_IO_HUP | G_IO_ERR) && node->io_read &&
-            aio_node_check(ctx, node->is_external)) {
+        if (revents & (G_IO_IN | G_IO_HUP | G_IO_ERR) && node->io_read) {
             result = true;
             break;
         }
-        if (revents & (G_IO_OUT | G_IO_ERR) && node->io_write &&
-            aio_node_check(ctx, node->is_external)) {
+        if (revents & (G_IO_OUT | G_IO_ERR) && node->io_write) {
             result = true;
             break;
         }
@@ -350,9 +345,7 @@ static bool aio_dispatch_handler(AioContext *ctx, AioHandler *node)
         QLIST_INSERT_HEAD(&ctx->poll_aio_handlers, node, node_poll);
     }
     if (!QLIST_IS_INSERTED(node, node_deleted) &&
-        poll_ready && revents == 0 &&
-        aio_node_check(ctx, node->is_external) &&
-        node->io_poll_ready) {
+        poll_ready && revents == 0 && node->io_poll_ready) {
         /*
          * Remove temporarily to avoid infinite loops when ->io_poll_ready()
          * calls aio_poll() before clearing the condition that made the poll
@@ -375,7 +368,6 @@ static bool aio_dispatch_handler(AioContext *ctx, AioHandler *node)
 
     if (!QLIST_IS_INSERTED(node, node_deleted) &&
         (revents & (G_IO_IN | G_IO_HUP | G_IO_ERR)) &&
-        aio_node_check(ctx, node->is_external) &&
         node->io_read) {
         node->io_read(node->opaque);
 
@@ -386,7 +378,6 @@ static bool aio_dispatch_handler(AioContext *ctx, AioHandler *node)
     }
     if (!QLIST_IS_INSERTED(node, node_deleted) &&
         (revents & (G_IO_OUT | G_IO_ERR)) &&
-        aio_node_check(ctx, node->is_external) &&
         node->io_write) {
         node->io_write(node->opaque);
         progress = true;
@@ -447,8 +438,7 @@ static bool run_poll_handlers_once(AioContext *ctx,
     AioHandler *tmp;
 
     QLIST_FOREACH_SAFE(node, &ctx->poll_aio_handlers, node_poll, tmp) {
-        if (aio_node_check(ctx, node->is_external) &&
-            node->io_poll(node->opaque)) {
+        if (node->io_poll(node->opaque)) {
             aio_add_poll_ready_handler(ready_list, node);
 
             node->poll_idle_timeout = now + POLL_IDLE_INTERVAL_NS;
diff --git a/util/aio-posix.h b/util/aio-posix.h
index 80b927c..4264c51 100644
--- a/util/aio-posix.h
+++ b/util/aio-posix.h
@@ -38,7 +38,6 @@ struct AioHandler {
 #endif
     int64_t poll_idle_timeout; /* when to stop userspace polling */
     bool poll_ready; /* has polling detected an event? */
-    bool is_external;
 };
 
 /* Add a handler to a ready list */
diff --git a/util/aio-win32.c b/util/aio-win32.c
index 6bded00..948ef47 100644
--- a/util/aio-win32.c
+++ b/util/aio-win32.c
@@ -32,7 +32,6 @@ struct AioHandler {
     GPollFD pfd;
     int deleted;
     void *opaque;
-    bool is_external;
     QLIST_ENTRY(AioHandler) node;
 };
 
@@ -64,7 +63,6 @@ static void aio_remove_fd_handler(AioContext *ctx, AioHandler *node)
 
 void aio_set_fd_handler(AioContext *ctx,
                         int fd,
-                        bool is_external,
                         IOHandler *io_read,
                         IOHandler *io_write,
                         AioPollFn *io_poll,
@@ -111,7 +109,6 @@ void aio_set_fd_handler(AioContext *ctx,
         node->opaque = opaque;
         node->io_read = io_read;
         node->io_write = io_write;
-        node->is_external = is_external;
 
         if (io_read) {
             bitmask |= FD_READ | FD_ACCEPT | FD_CLOSE;
@@ -135,7 +132,6 @@ void aio_set_fd_handler(AioContext *ctx,
 
 void aio_set_event_notifier(AioContext *ctx,
                             EventNotifier *e,
-                            bool is_external,
                             EventNotifierHandler *io_notify,
                             AioPollFn *io_poll,
                             EventNotifierHandler *io_poll_ready)
@@ -161,7 +157,6 @@ void aio_set_event_notifier(AioContext *ctx,
             node->e = e;
             node->pfd.fd = (uintptr_t)event_notifier_get_handle(e);
             node->pfd.events = G_IO_IN;
-            node->is_external = is_external;
             QLIST_INSERT_HEAD_RCU(&ctx->aio_handlers, node, node);
 
             g_source_add_poll(&ctx->source, &node->pfd);
@@ -368,8 +363,7 @@ bool aio_poll(AioContext *ctx, bool blocking)
     /* fill fd sets */
     count = 0;
     QLIST_FOREACH_RCU(node, &ctx->aio_handlers, node) {
-        if (!node->deleted && node->io_notify
-            && aio_node_check(ctx, node->is_external)) {
+        if (!node->deleted && node->io_notify) {
             assert(count < MAXIMUM_WAIT_OBJECTS);
             events[count++] = event_notifier_get_handle(node->e);
         }
diff --git a/util/async.c b/util/async.c
index 055070f..8f90ddc 100644
--- a/util/async.c
+++ b/util/async.c
@@ -409,7 +409,7 @@ aio_ctx_finalize(GSource     *source)
         g_free(bh);
     }
 
-    aio_set_event_notifier(ctx, &ctx->notifier, false, NULL, NULL, NULL);
+    aio_set_event_notifier(ctx, &ctx->notifier, NULL, NULL, NULL);
     event_notifier_cleanup(&ctx->notifier);
     qemu_rec_mutex_destroy(&ctx->lock);
     qemu_lockcnt_destroy(&ctx->list_lock);
@@ -593,7 +593,6 @@ AioContext *aio_context_new(Error **errp)
     QSLIST_INIT(&ctx->scheduled_coroutines);
 
     aio_set_event_notifier(ctx, &ctx->notifier,
-                           false,
                            aio_context_notifier_cb,
                            aio_context_notifier_poll,
                            aio_context_notifier_poll_ready);
diff --git a/util/fdmon-epoll.c b/util/fdmon-epoll.c
index 1683aa1..c6413cb 100644
--- a/util/fdmon-epoll.c
+++ b/util/fdmon-epoll.c
@@ -64,11 +64,6 @@ static int fdmon_epoll_wait(AioContext *ctx, AioHandlerList *ready_list,
     int i, ret = 0;
     struct epoll_event events[128];
 
-    /* Fall back while external clients are disabled */
-    if (qatomic_read(&ctx->external_disable_cnt)) {
-        return fdmon_poll_ops.wait(ctx, ready_list, timeout);
-    }
-
     if (timeout > 0) {
         ret = qemu_poll_ns(&pfd, 1, timeout);
         if (ret > 0) {
@@ -133,11 +128,6 @@ bool fdmon_epoll_try_upgrade(AioContext *ctx, unsigned npfd)
         return false;
     }
 
-    /* Do not upgrade while external clients are disabled */
-    if (qatomic_read(&ctx->external_disable_cnt)) {
-        return false;
-    }
-
     if (npfd < EPOLL_ENABLE_THRESHOLD) {
         return false;
     }
diff --git a/util/fdmon-io_uring.c b/util/fdmon-io_uring.c
index ab43052..17ec18b 100644
--- a/util/fdmon-io_uring.c
+++ b/util/fdmon-io_uring.c
@@ -276,11 +276,6 @@ static int fdmon_io_uring_wait(AioContext *ctx, AioHandlerList *ready_list,
     unsigned wait_nr = 1; /* block until at least one cqe is ready */
     int ret;
 
-    /* Fall back while external clients are disabled */
-    if (qatomic_read(&ctx->external_disable_cnt)) {
-        return fdmon_poll_ops.wait(ctx, ready_list, timeout);
-    }
-
     if (timeout == 0) {
         wait_nr = 0; /* non-blocking */
     } else if (timeout > 0) {
@@ -315,8 +310,7 @@ static bool fdmon_io_uring_need_wait(AioContext *ctx)
         return true;
     }
 
-    /* Are we falling back to fdmon-poll? */
-    return qatomic_read(&ctx->external_disable_cnt);
+    return false;
 }
 
 static const FDMonOps fdmon_io_uring_ops = {
diff --git a/util/fdmon-poll.c b/util/fdmon-poll.c
index 5fe3b47..17df917 100644
--- a/util/fdmon-poll.c
+++ b/util/fdmon-poll.c
@@ -65,8 +65,7 @@ static int fdmon_poll_wait(AioContext *ctx, AioHandlerList *ready_list,
     assert(npfd == 0);
 
     QLIST_FOREACH_RCU(node, &ctx->aio_handlers, node) {
-        if (!QLIST_IS_INSERTED(node, node_deleted) && node->pfd.events
-                && aio_node_check(ctx, node->is_external)) {
+        if (!QLIST_IS_INSERTED(node, node_deleted) && node->pfd.events) {
             add_pollfd(node);
         }
     }
diff --git a/util/main-loop.c b/util/main-loop.c
index 7022f02..014c795 100644
--- a/util/main-loop.c
+++ b/util/main-loop.c
@@ -644,14 +644,13 @@ void qemu_set_fd_handler(int fd,
                          void *opaque)
 {
     iohandler_init();
-    aio_set_fd_handler(iohandler_ctx, fd, false,
-                       fd_read, fd_write, NULL, NULL, opaque);
+    aio_set_fd_handler(iohandler_ctx, fd, fd_read, fd_write, NULL, NULL,
+                       opaque);
 }
 
 void event_notifier_set_handler(EventNotifier *e,
                                 EventNotifierHandler *handler)
 {
     iohandler_init();
-    aio_set_event_notifier(iohandler_ctx, e, false,
-                           handler, NULL, NULL);
+    aio_set_event_notifier(iohandler_ctx, e, handler, NULL, NULL);
 }
diff --git a/util/qemu-coroutine-io.c b/util/qemu-coroutine-io.c
index d791932..364f4d5 100644
--- a/util/qemu-coroutine-io.c
+++ b/util/qemu-coroutine-io.c
@@ -74,8 +74,7 @@ typedef struct {
 static void fd_coroutine_enter(void *opaque)
 {
     FDYieldUntilData *data = opaque;
-    aio_set_fd_handler(data->ctx, data->fd, false,
-                       NULL, NULL, NULL, NULL, NULL);
+    aio_set_fd_handler(data->ctx, data->fd, NULL, NULL, NULL, NULL, NULL);
     qemu_coroutine_enter(data->co);
 }
 
@@ -87,7 +86,7 @@ void coroutine_fn yield_until_fd_readable(int fd)
     data.ctx = qemu_get_current_aio_context();
     data.co = qemu_coroutine_self();
     data.fd = fd;
-    aio_set_fd_handler(
-        data.ctx, fd, false, fd_coroutine_enter, NULL, NULL, NULL, &data);
+    aio_set_fd_handler(data.ctx, fd, fd_coroutine_enter, NULL, NULL, NULL,
+                       &data);
     qemu_coroutine_yield();
 }
diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
index a12b2d1..cd17fb5 100644
--- a/util/vhost-user-server.c
+++ b/util/vhost-user-server.c
@@ -278,7 +278,7 @@ set_watch(VuDev *vu_dev, int fd, int vu_evt,
         vu_fd_watch->fd = fd;
         vu_fd_watch->cb = cb;
         qemu_socket_set_nonblock(fd);
-        aio_set_fd_handler(server->ioc->ctx, fd, false, kick_handler,
+        aio_set_fd_handler(server->ioc->ctx, fd, kick_handler,
                            NULL, NULL, NULL, vu_fd_watch);
         vu_fd_watch->vu_dev = vu_dev;
         vu_fd_watch->pvt = pvt;
@@ -299,8 +299,7 @@ static void remove_watch(VuDev *vu_dev, int fd)
     if (!vu_fd_watch) {
         return;
     }
-    aio_set_fd_handler(server->ioc->ctx, fd, false,
-                       NULL, NULL, NULL, NULL, NULL);
+    aio_set_fd_handler(server->ioc->ctx, fd, NULL, NULL, NULL, NULL, NULL);
 
     QTAILQ_REMOVE(&server->vu_fd_watches, vu_fd_watch, next);
     g_free(vu_fd_watch);
@@ -362,7 +361,7 @@ void vhost_user_server_stop(VuServer *server)
         VuFdWatch *vu_fd_watch;
 
         QTAILQ_FOREACH(vu_fd_watch, &server->vu_fd_watches, next) {
-            aio_set_fd_handler(server->ctx, vu_fd_watch->fd, false,
+            aio_set_fd_handler(server->ctx, vu_fd_watch->fd,
                                NULL, NULL, NULL, NULL, vu_fd_watch);
         }
 
@@ -403,7 +402,7 @@ void vhost_user_server_attach_aio_context(VuServer *server, AioContext *ctx)
     qio_channel_attach_aio_context(server->ioc, ctx);
 
     QTAILQ_FOREACH(vu_fd_watch, &server->vu_fd_watches, next) {
-        aio_set_fd_handler(ctx, vu_fd_watch->fd, false, kick_handler, NULL,
+        aio_set_fd_handler(ctx, vu_fd_watch->fd, kick_handler, NULL,
                            NULL, NULL, vu_fd_watch);
     }
 
@@ -417,7 +416,7 @@ void vhost_user_server_detach_aio_context(VuServer *server)
         VuFdWatch *vu_fd_watch;
 
         QTAILQ_FOREACH(vu_fd_watch, &server->vu_fd_watches, next) {
-            aio_set_fd_handler(server->ctx, vu_fd_watch->fd, false,
+            aio_set_fd_handler(server->ctx, vu_fd_watch->fd,
                                NULL, NULL, NULL, NULL, vu_fd_watch);
         }