26ba25
From c05f0a720ff742af5c010f5ab2c0661a10cfa536 Mon Sep 17 00:00:00 2001
26ba25
From: Kevin Wolf <kwolf@redhat.com>
26ba25
Date: Wed, 10 Oct 2018 20:08:36 +0100
26ba25
Subject: [PATCH 05/49] block: Use bdrv_do_drain_begin/end in bdrv_drain_all()
26ba25
26ba25
RH-Author: Kevin Wolf <kwolf@redhat.com>
26ba25
Message-id: <20181010200843.6710-3-kwolf@redhat.com>
26ba25
Patchwork-id: 82585
26ba25
O-Subject: [RHEL-8 qemu-kvm PATCH 02/44] block: Use bdrv_do_drain_begin/end in bdrv_drain_all()
26ba25
Bugzilla: 1637976
26ba25
RH-Acked-by: Max Reitz <mreitz@redhat.com>
26ba25
RH-Acked-by: John Snow <jsnow@redhat.com>
26ba25
RH-Acked-by: Thomas Huth <thuth@redhat.com>
26ba25
26ba25
bdrv_do_drain_begin/end() implement already everything that
26ba25
bdrv_drain_all_begin/end() need and currently still do manually: Disable
26ba25
external events, call parent drain callbacks, call block driver
26ba25
callbacks.
26ba25
26ba25
It also does two more things:
26ba25
26ba25
The first is incrementing bs->quiesce_counter. bdrv_drain_all() already
26ba25
stood out in the test case by behaving different from the other drain
26ba25
variants. Adding this is not only safe, but in fact a bug fix.
26ba25
26ba25
The second is calling bdrv_drain_recurse(). We already do that later in
26ba25
the same function in a loop, so basically doing an early first iteration
26ba25
doesn't hurt.
26ba25
26ba25
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
26ba25
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
26ba25
(cherry picked from commit 79ab8b21dc19c08adc407504e456ff64b9dacb66)
26ba25
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
26ba25
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
26ba25
---
26ba25
 block/io.c              | 10 ++--------
26ba25
 tests/test-bdrv-drain.c | 14 ++++----------
26ba25
 2 files changed, 6 insertions(+), 18 deletions(-)
26ba25
26ba25
diff --git a/block/io.c b/block/io.c
26ba25
index 7e0a169..230b551 100644
26ba25
--- a/block/io.c
26ba25
+++ b/block/io.c
26ba25
@@ -412,11 +412,8 @@ void bdrv_drain_all_begin(void)
26ba25
     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
26ba25
         AioContext *aio_context = bdrv_get_aio_context(bs);
26ba25
 
26ba25
-        /* Stop things in parent-to-child order */
26ba25
         aio_context_acquire(aio_context);
26ba25
-        aio_disable_external(aio_context);
26ba25
-        bdrv_parent_drained_begin(bs, NULL);
26ba25
-        bdrv_drain_invoke(bs, true, true);
26ba25
+        bdrv_do_drained_begin(bs, true, NULL);
26ba25
         aio_context_release(aio_context);
26ba25
 
26ba25
         if (!g_slist_find(aio_ctxs, aio_context)) {
26ba25
@@ -457,11 +454,8 @@ void bdrv_drain_all_end(void)
26ba25
     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
26ba25
         AioContext *aio_context = bdrv_get_aio_context(bs);
26ba25
 
26ba25
-        /* Re-enable things in child-to-parent order */
26ba25
         aio_context_acquire(aio_context);
26ba25
-        bdrv_drain_invoke(bs, false, true);
26ba25
-        bdrv_parent_drained_end(bs, NULL);
26ba25
-        aio_enable_external(aio_context);
26ba25
+        bdrv_do_drained_end(bs, true, NULL);
26ba25
         aio_context_release(aio_context);
26ba25
     }
26ba25
 }
26ba25
diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
26ba25
index dee0a10..f1276a1 100644
26ba25
--- a/tests/test-bdrv-drain.c
26ba25
+++ b/tests/test-bdrv-drain.c
26ba25
@@ -276,8 +276,7 @@ static void test_quiesce_common(enum drain_type drain_type, bool recursive)
26ba25
 
26ba25
 static void test_quiesce_drain_all(void)
26ba25
 {
26ba25
-    // XXX drain_all doesn't quiesce
26ba25
-    //test_quiesce_common(BDRV_DRAIN_ALL, true);
26ba25
+    test_quiesce_common(BDRV_DRAIN_ALL, true);
26ba25
 }
26ba25
 
26ba25
 static void test_quiesce_drain(void)
26ba25
@@ -319,12 +318,7 @@ static void test_nested(void)
26ba25
 
26ba25
     for (outer = 0; outer < DRAIN_TYPE_MAX; outer++) {
26ba25
         for (inner = 0; inner < DRAIN_TYPE_MAX; inner++) {
26ba25
-            /* XXX bdrv_drain_all() doesn't increase the quiesce_counter */
26ba25
-            int bs_quiesce      = (outer != BDRV_DRAIN_ALL) +
26ba25
-                                  (inner != BDRV_DRAIN_ALL);
26ba25
-            int backing_quiesce = (outer == BDRV_SUBTREE_DRAIN) +
26ba25
-                                  (inner == BDRV_SUBTREE_DRAIN);
26ba25
-            int backing_cb_cnt  = (outer != BDRV_DRAIN) +
26ba25
+            int backing_quiesce = (outer != BDRV_DRAIN) +
26ba25
                                   (inner != BDRV_DRAIN);
26ba25
 
26ba25
             g_assert_cmpint(bs->quiesce_counter, ==, 0);
26ba25
@@ -335,10 +329,10 @@ static void test_nested(void)
26ba25
             do_drain_begin(outer, bs);
26ba25
             do_drain_begin(inner, bs);
26ba25
 
26ba25
-            g_assert_cmpint(bs->quiesce_counter, ==, bs_quiesce);
26ba25
+            g_assert_cmpint(bs->quiesce_counter, ==, 2);
26ba25
             g_assert_cmpint(backing->quiesce_counter, ==, backing_quiesce);
26ba25
             g_assert_cmpint(s->drain_count, ==, 2);
26ba25
-            g_assert_cmpint(backing_s->drain_count, ==, backing_cb_cnt);
26ba25
+            g_assert_cmpint(backing_s->drain_count, ==, backing_quiesce);
26ba25
 
26ba25
             do_drain_end(inner, bs);
26ba25
             do_drain_end(outer, bs);
26ba25
-- 
26ba25
1.8.3.1
26ba25