[PATCH 03/15] block: Pull polling out of bdrv_parent_drained_begin_single()

[Paolo Bonzini]

Only one caller of bdrv_parent_drained_begin_single() passes poll=true;
move the polling to that one caller.

While this requires exposing bdrv_parent_drained_poll_single to outside
block/io.c, this is not a big deal because the bdrv_parent_drained_*_single
functions are really internal between block.c and block/io.c.  So make
that clear while we're at it, by moving them to block_int-io.h.

Based on a patch by Kevin Wolf <kwolf@redhat.com>.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 block.c                      |  4 +++-
 block/io.c                   | 10 +++-------
 include/block/block-io.h     | 15 ---------------
 include/block/block_int-io.h | 21 +++++++++++++++++++++
 4 files changed, 27 insertions(+), 23 deletions(-)

diff --git a/block.c b/block.c
index 2f2123f4a4e5..c542a0a33358 100644
--- a/block.c
+++ b/block.c
@@ -2830,7 +2830,9 @@ static void bdrv_replace_child_noperm(BdrvChild *child,
      */
     new_bs_quiesce_counter = (new_bs ? new_bs->quiesce_counter : 0);
     if (new_bs_quiesce_counter && !child->quiesced_parent) {
-        bdrv_parent_drained_begin_single(child, true);
+        bdrv_parent_drained_begin_single(child);
+        AIO_WAIT_WHILE(bdrv_child_get_parent_aio_context(child),
+                       bdrv_parent_drained_poll_single(child));
     }
 
     if (old_bs) {
diff --git a/block/io.c b/block/io.c
index 571ff8c6493a..f4444b7777d9 100644
--- a/block/io.c
+++ b/block/io.c
@@ -53,7 +53,7 @@ static void bdrv_parent_drained_begin(BlockDriverState *bs, 
BdrvChild *ignore)
         if (c == ignore) {
             continue;
         }
-        bdrv_parent_drained_begin_single(c, false);
+        bdrv_parent_drained_begin_single(c);
     }
 }
 
@@ -81,7 +81,7 @@ static void bdrv_parent_drained_end(BlockDriverState *bs, 
BdrvChild *ignore)
     }
 }
 
-static bool bdrv_parent_drained_poll_single(BdrvChild *c)
+bool bdrv_parent_drained_poll_single(BdrvChild *c)
 {
     if (c->klass->drained_poll) {
         return c->klass->drained_poll(c);
@@ -105,9 +105,8 @@ static bool bdrv_parent_drained_poll(BlockDriverState *bs, 
BdrvChild *ignore,
     return busy;
 }
 
-void bdrv_parent_drained_begin_single(BdrvChild *c, bool poll)
+void bdrv_parent_drained_begin_single(BdrvChild *c)
 {
-    AioContext *ctx = bdrv_child_get_parent_aio_context(c);
     IO_OR_GS_CODE();
 
     assert(!c->quiesced_parent);
@@ -116,9 +115,6 @@ void bdrv_parent_drained_begin_single(BdrvChild *c, bool 
poll)
     if (c->klass->drained_begin) {
         c->klass->drained_begin(c);
     }
-    if (poll) {
-        AIO_WAIT_WHILE(ctx, bdrv_parent_drained_poll_single(c));
-    }
 }
 
 static void bdrv_merge_limits(BlockLimits *dst, const BlockLimits *src)
diff --git a/include/block/block-io.h b/include/block/block-io.h
index 0e0cd1249705..10659a3f246c 100644
--- a/include/block/block-io.h
+++ b/include/block/block-io.h
@@ -305,21 +305,6 @@ bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector 
*qiov, int64_t pos);
 int co_wrapper_mixed
 bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
 
-/**
- * bdrv_parent_drained_begin_single:
- *
- * Begin a quiesced section for the parent of @c. If @poll is true, wait for
- * any pending activity to cease.
- */
-void bdrv_parent_drained_begin_single(BdrvChild *c, bool poll);
-
-/**
- * bdrv_parent_drained_end_single:
- *
- * End a quiesced section for the parent of @c.
- */
-void bdrv_parent_drained_end_single(BdrvChild *c);
-
 /**
  * bdrv_drain_poll:
  *
diff --git a/include/block/block_int-io.h b/include/block/block_int-io.h
index 8bc061ebb895..0ced9c025acb 100644
--- a/include/block/block_int-io.h
+++ b/include/block/block_int-io.h
@@ -179,4 +179,25 @@ void bdrv_bsc_invalidate_range(BlockDriverState *bs,
  */
 void bdrv_bsc_fill(BlockDriverState *bs, int64_t offset, int64_t bytes);
 
+/**
+ * bdrv_parent_drained_begin_single:
+ *
+ * Begin a quiesced section for the parent of @c.
+ */
+void bdrv_parent_drained_begin_single(BdrvChild *c);
+
+/**
+ * bdrv_parent_drained_begin_single:
+ *
+ * Check whether the parent of @c has quiesced.
+ */
+bool bdrv_parent_drained_poll_single(BdrvChild *c);
+
+/**
+ * bdrv_parent_drained_end_single:
+ *
+ * End a quiesced section for the parent of @c.
+ */
+void bdrv_parent_drained_end_single(BdrvChild *c);
+
 #endif /* BLOCK_INT_IO_H */
-- 
2.38.1