[02/19] block: Use bdrv_do_drain_begin/end in bdrv_drain_all()
diff mbox

Message ID 20180411163940.2523-3-kwolf@redhat.com
State New
Headers show

Commit Message

Kevin Wolf April 11, 2018, 4:39 p.m. UTC
bdrv_do_drain_begin/end() implement already everything that
bdrv_drain_all_begin/end() need and currently still do manually: Disable
external events, call parent drain callbacks, call block driver
callbacks.

It also does two more things:

The first is incrementing bs->quiesce_counter. bdrv_drain_all() already
stood out in the test case by behaving different from the other drain
variants. Adding this is not only safe, but in fact a bug fix.

The second is calling bdrv_drain_recurse(). We already do that later in
the same function in a loop, so basically doing an early first iteration
doesn't hurt.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/io.c              | 10 ++--------
 tests/test-bdrv-drain.c | 14 ++++----------
 2 files changed, 6 insertions(+), 18 deletions(-)

Comments

Stefan Hajnoczi April 20, 2018, 7:07 a.m. UTC | #1
On Wed, Apr 11, 2018 at 06:39:23PM +0200, Kevin Wolf wrote:
> bdrv_do_drain_begin/end() implement already everything that
> bdrv_drain_all_begin/end() need and currently still do manually: Disable
> external events, call parent drain callbacks, call block driver
> callbacks.
> 
> It also does two more things:
> 
> The first is incrementing bs->quiesce_counter. bdrv_drain_all() already
> stood out in the test case by behaving different from the other drain
> variants. Adding this is not only safe, but in fact a bug fix.
> 
> The second is calling bdrv_drain_recurse(). We already do that later in
> the same function in a loop, so basically doing an early first iteration
> doesn't hurt.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block/io.c              | 10 ++--------
>  tests/test-bdrv-drain.c | 14 ++++----------
>  2 files changed, 6 insertions(+), 18 deletions(-)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

Patch
diff mbox

diff --git a/block/io.c b/block/io.c
index 28e71221b0..cad59db2f4 100644
--- a/block/io.c
+++ b/block/io.c
@@ -412,11 +412,8 @@  void bdrv_drain_all_begin(void)
     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
         AioContext *aio_context = bdrv_get_aio_context(bs);
 
-        /* Stop things in parent-to-child order */
         aio_context_acquire(aio_context);
-        aio_disable_external(aio_context);
-        bdrv_parent_drained_begin(bs, NULL);
-        bdrv_drain_invoke(bs, true, true);
+        bdrv_do_drained_begin(bs, true, NULL);
         aio_context_release(aio_context);
 
         if (!g_slist_find(aio_ctxs, aio_context)) {
@@ -457,11 +454,8 @@  void bdrv_drain_all_end(void)
     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
         AioContext *aio_context = bdrv_get_aio_context(bs);
 
-        /* Re-enable things in child-to-parent order */
         aio_context_acquire(aio_context);
-        bdrv_drain_invoke(bs, false, true);
-        bdrv_parent_drained_end(bs, NULL);
-        aio_enable_external(aio_context);
+        bdrv_do_drained_end(bs, true, NULL);
         aio_context_release(aio_context);
     }
 }
diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
index 29634102d8..cd870609c5 100644
--- a/tests/test-bdrv-drain.c
+++ b/tests/test-bdrv-drain.c
@@ -276,8 +276,7 @@  static void test_quiesce_common(enum drain_type drain_type, bool recursive)
 
 static void test_quiesce_drain_all(void)
 {
-    // XXX drain_all doesn't quiesce
-    //test_quiesce_common(BDRV_DRAIN_ALL, true);
+    test_quiesce_common(BDRV_DRAIN_ALL, true);
 }
 
 static void test_quiesce_drain(void)
@@ -319,12 +318,7 @@  static void test_nested(void)
 
     for (outer = 0; outer < DRAIN_TYPE_MAX; outer++) {
         for (inner = 0; inner < DRAIN_TYPE_MAX; inner++) {
-            /* XXX bdrv_drain_all() doesn't increase the quiesce_counter */
-            int bs_quiesce      = (outer != BDRV_DRAIN_ALL) +
-                                  (inner != BDRV_DRAIN_ALL);
-            int backing_quiesce = (outer == BDRV_SUBTREE_DRAIN) +
-                                  (inner == BDRV_SUBTREE_DRAIN);
-            int backing_cb_cnt  = (outer != BDRV_DRAIN) +
+            int backing_quiesce = (outer != BDRV_DRAIN) +
                                   (inner != BDRV_DRAIN);
 
             g_assert_cmpint(bs->quiesce_counter, ==, 0);
@@ -335,10 +329,10 @@  static void test_nested(void)
             do_drain_begin(outer, bs);
             do_drain_begin(inner, bs);
 
-            g_assert_cmpint(bs->quiesce_counter, ==, bs_quiesce);
+            g_assert_cmpint(bs->quiesce_counter, ==, 2);
             g_assert_cmpint(backing->quiesce_counter, ==, backing_quiesce);
             g_assert_cmpint(s->drain_count, ==, 2);
-            g_assert_cmpint(backing_s->drain_count, ==, backing_cb_cnt);
+            g_assert_cmpint(backing_s->drain_count, ==, backing_quiesce);
 
             do_drain_end(inner, bs);
             do_drain_end(outer, bs);