|
 |
357786 |
From 68265b080cec07c5a6ba6b1c6fbd867f4d9cf9ba Mon Sep 17 00:00:00 2001
|
|
|
357786 |
From: Kevin Wolf <kwolf@redhat.com>
|
|
|
357786 |
Date: Fri, 14 Sep 2018 10:55:34 +0200
|
|
|
357786 |
Subject: [PATCH 43/49] block-backend: Decrease in_flight only after callback
|
|
|
357786 |
|
|
|
357786 |
RH-Author: Kevin Wolf <kwolf@redhat.com>
|
|
|
357786 |
Message-id: <20180914105540.18077-37-kwolf@redhat.com>
|
|
|
357786 |
Patchwork-id: 82187
|
|
|
357786 |
O-Subject: [RHV-7.6 qemu-kvm-rhev PATCH 36/42] block-backend: Decrease in_flight only after callback
|
|
|
357786 |
Bugzilla: 1601212
|
|
|
357786 |
RH-Acked-by: John Snow <jsnow@redhat.com>
|
|
|
357786 |
RH-Acked-by: Max Reitz <mreitz@redhat.com>
|
|
|
357786 |
RH-Acked-by: Fam Zheng <famz@redhat.com>
|
|
|
357786 |
|
|
|
357786 |
Request callbacks can do pretty much anything, including operations that
|
|
|
357786 |
will yield from the coroutine (such as draining the backend). In that
|
|
|
357786 |
case, a decreased in_flight would be visible to other code and could
|
|
|
357786 |
lead to a drain completing while the callback hasn't actually completed
|
|
|
357786 |
yet.
|
|
|
357786 |
|
|
|
357786 |
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
|
|
|
357786 |
Reviewed-by: Fam Zheng <famz@redhat.com>
|
|
|
357786 |
Reviewed-by: Max Reitz <mreitz@redhat.com>
|
|
|
357786 |
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
|
|
|
357786 |
---
|
|
|
357786 |
block/block-backend.c | 10 +++++++++-
|
|
|
357786 |
1 file changed, 9 insertions(+), 1 deletion(-)
|
|
|
357786 |
|
|
|
357786 |
diff --git a/block/block-backend.c b/block/block-backend.c
|
|
|
357786 |
index 1adf76b..466bc27 100644
|
|
|
357786 |
--- a/block/block-backend.c
|
|
|
357786 |
+++ b/block/block-backend.c
|
|
|
357786 |
@@ -1341,8 +1341,16 @@ static const AIOCBInfo blk_aio_em_aiocb_info = {
|
|
|
357786 |
static void blk_aio_complete(BlkAioEmAIOCB *acb)
|
|
|
357786 |
{
|
|
|
357786 |
if (acb->has_returned) {
|
|
|
357786 |
- blk_dec_in_flight(acb->rwco.blk);
|
|
|
357786 |
+ if (qemu_get_current_aio_context() == qemu_get_aio_context()) {
|
|
|
357786 |
+ /* If we are in the main thread, the callback is allowed to unref
|
|
|
357786 |
+ * the BlockBackend, so we have to hold an additional reference */
|
|
|
357786 |
+ blk_ref(acb->rwco.blk);
|
|
|
357786 |
+ }
|
|
|
357786 |
acb->common.cb(acb->common.opaque, acb->rwco.ret);
|
|
|
357786 |
+ blk_dec_in_flight(acb->rwco.blk);
|
|
|
357786 |
+ if (qemu_get_current_aio_context() == qemu_get_aio_context()) {
|
|
|
357786 |
+ blk_unref(acb->rwco.blk);
|
|
|
357786 |
+ }
|
|
|
357786 |
qemu_aio_unref(acb);
|
|
|
357786 |
}
|
|
|
357786 |
}
|
|
|
357786 |
--
|
|
|
357786 |
1.8.3.1
|
|
|
357786 |
|