[Qemu-devel] [PATCH 3/7] block: move restarting of throttled reqs to block/throttle-groups.c

[Paolo Bonzini <pbonzini@redhat.com>]

We want to remove throttled_reqs from block/io.c.  This is the easy
part---hide the handling of throttled_reqs during disable/enable of
throttling within throttle-groups.c.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
        v1->v2: only restart first request after throttle_group_config
---
 block/io.c                      | 15 +--------------
 block/throttle-groups.c         | 16 ++++++++++++++++
 include/block/throttle-groups.h |  1 +
 3 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/block/io.c b/block/io.c
index 3703426..93696df 100644
--- a/block/io.c
+++ b/block/io.c
@@ -60,28 +60,15 @@ static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,
 void bdrv_set_io_limits(BlockDriverState *bs,
                         ThrottleConfig *cfg)
 {
-    int i;
-
     throttle_group_config(bs, cfg);
-
-    for (i = 0; i < 2; i++) {
-        qemu_co_enter_next(&bs->throttled_reqs[i]);
-    }
 }
 
 static void bdrv_start_throttled_reqs(BlockDriverState *bs)
 {
     bool enabled = bs->io_limits_enabled;
-    int i;
 
     bs->io_limits_enabled = false;
-
-    for (i = 0; i < 2; i++) {
-        while (qemu_co_enter_next(&bs->throttled_reqs[i])) {
-            ;
-        }
-    }
-
+    throttle_group_restart_bs(bs);
     bs->io_limits_enabled = enabled;
 }
 
diff --git a/block/throttle-groups.c b/block/throttle-groups.c
index 4920e09..9f52d2b 100644
--- a/block/throttle-groups.c
+++ b/block/throttle-groups.c
@@ -313,6 +313,17 @@ void coroutine_fn throttle_group_co_io_limits_intercept(BlockDriverState *bs,
     qemu_mutex_unlock(&tg->lock);
 }
 
+void throttle_group_restart_bs(BlockDriverState *bs)
+{
+    int i;
+
+    for (i = 0; i < 2; i++) {
+        while (qemu_co_enter_next(&bs->throttled_reqs[i])) {
+            ;
+        }
+    }
+}
+
 /* Update the throttle configuration for a particular group. Similar
  * to throttle_config(), but guarantees atomicity within the
  * throttling group.
@@ -335,6 +346,11 @@ void throttle_group_config(BlockDriverState *bs, ThrottleConfig *cfg)
     }
     throttle_config(ts, tt, cfg);
     qemu_mutex_unlock(&tg->lock);
+
+    aio_context_acquire(bdrv_get_aio_context(bs));
+    qemu_co_enter_next(&bs->throttled_reqs[0]);
+    qemu_co_enter_next(&bs->throttled_reqs[1]);
+    aio_context_release(bdrv_get_aio_context(bs));
 }
 
 /* Get the throttle configuration from a particular group. Similar to
diff --git a/include/block/throttle-groups.h b/include/block/throttle-groups.h
index aba28f3..395f72d 100644
--- a/include/block/throttle-groups.h
+++ b/include/block/throttle-groups.h
@@ -38,6 +38,7 @@ void throttle_group_get_config(BlockDriverState *bs, ThrottleConfig *cfg);
 
 void throttle_group_register_bs(BlockDriverState *bs, const char *groupname);
 void throttle_group_unregister_bs(BlockDriverState *bs);
+void throttle_group_restart_bs(BlockDriverState *bs);
 
 void coroutine_fn throttle_group_co_io_limits_intercept(BlockDriverState *bs,
                                                         unsigned int bytes,
-- 
1.8.3.1