Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2019-07-02' into staging

[mirror_qemu.git] / block / throttle-groups.c

diff --git a/block/throttle-groups.c b/block/throttle-groups.c
index d46c56b31e7ca57d7cbd4bf871c25fade729224a..a5a20379244e20a7808b7d106972e36d29cbb60f 100644 (file)
--- a/block/throttle-groups.c
+++ b/block/throttle-groups.c
@@ -36,6 +36,7 @@
 
 static void throttle_group_obj_init(Object *obj);
 static void throttle_group_obj_complete(UserCreatable *obj, Error **errp);
+static void timer_cb(ThrottleGroupMember *tgm, bool is_write);
 
 /* The ThrottleGroup structure (with its ThrottleState) is shared
  * among different ThrottleGroupMembers and it's independent from
@@ -414,6 +415,9 @@ static void coroutine_fn throttle_group_restart_queue_entry(void *opaque)
     }
 
     g_free(data);
+
+    atomic_dec(&tgm->restart_pending);
+    aio_wait_kick();
 }
 
 static void throttle_group_restart_queue(ThrottleGroupMember *tgm, bool is_write)
@@ -424,15 +428,33 @@ static void throttle_group_restart_queue(ThrottleGroupMember *tgm, bool is_write
     rd->tgm = tgm;
     rd->is_write = is_write;
 
+    /* This function is called when a timer is fired or when
+     * throttle_group_restart_tgm() is called. Either way, there can
+     * be no timer pending on this tgm at this point */
+    assert(!timer_pending(tgm->throttle_timers.timers[is_write]));
+
+    atomic_inc(&tgm->restart_pending);
+
     co = qemu_coroutine_create(throttle_group_restart_queue_entry, rd);
     aio_co_enter(tgm->aio_context, co);
 }
 
 void throttle_group_restart_tgm(ThrottleGroupMember *tgm)
 {
+    int i;
+
     if (tgm->throttle_state) {
-        throttle_group_restart_queue(tgm, 0);
-        throttle_group_restart_queue(tgm, 1);
+        for (i = 0; i < 2; i++) {
+            QEMUTimer *t = tgm->throttle_timers.timers[i];
+            if (timer_pending(t)) {
+                /* If there's a pending timer on this tgm, fire it now */
+                timer_del(t);
+                timer_cb(tgm, i);
+            } else {
+                /* Else run the next request from the queue manually */
+                throttle_group_restart_queue(tgm, i);
+            }
+        }
     }
 }
 
@@ -521,6 +543,7 @@ void throttle_group_register_tgm(ThrottleGroupMember *tgm,
 
     tgm->throttle_state = ts;
     tgm->aio_context = ctx;
+    atomic_set(&tgm->restart_pending, 0);
 
     qemu_mutex_lock(&tg->lock);
     /* If the ThrottleGroup is new set this ThrottleGroupMember as the token */
@@ -567,16 +590,14 @@ void throttle_group_unregister_tgm(ThrottleGroupMember *tgm)
         return;
     }
 
-    assert(tgm->pending_reqs[0] == 0 && tgm->pending_reqs[1] == 0);
-    assert(qemu_co_queue_empty(&tgm->throttled_reqs[0]));
-    assert(qemu_co_queue_empty(&tgm->throttled_reqs[1]));
+    /* Wait for throttle_group_restart_queue_entry() coroutines to finish */
+    AIO_WAIT_WHILE(tgm->aio_context, atomic_read(&tgm->restart_pending) > 0);
 
     qemu_mutex_lock(&tg->lock);
     for (i = 0; i < 2; i++) {
-        if (timer_pending(tgm->throttle_timers.timers[i])) {
-            tg->any_timer_armed[i] = false;
-            schedule_next_request(tgm, i);
-        }
+        assert(tgm->pending_reqs[i] == 0);
+        assert(qemu_co_queue_empty(&tgm->throttled_reqs[i]));
+        assert(!timer_pending(tgm->throttle_timers.timers[i]));
         if (tg->tokens[i] == tgm) {
             token = throttle_group_next_tgm(tgm);
             /* Take care of the case where this is the last tgm in the group */