From a638ecdb8b6a2edab62cb6ca198240df65953aca Mon Sep 17 00:00:00 2001
Message-Id: <a638ecdb8b6a2edab62cb6ca198240df65953aca.1430330503.git.jen@redhat.com>
In-Reply-To: <d0ac017560c13e37ad318c0def2bc917bc5eda21.1430330503.git.jen@redhat.com>
References: <d0ac017560c13e37ad318c0def2bc917bc5eda21.1430330503.git.jen@redhat.com>
From: Fam Zheng <famz@redhat.com>
Date: Fri, 24 Apr 2015 08:44:26 -0500
Subject: [CHANGE 06/29] block: Add bdrv_aio_cancel_async
To: rhvirt-patches@redhat.com,
jen@redhat.com
RH-Author: Fam Zheng <famz@redhat.com>
Message-id: <1429865088-13298-7-git-send-email-famz@redhat.com>
Patchwork-id: 64907
O-Subject: [RHEL-6.7 qemu-kvm PATCH v7 06/28] block: Add bdrv_aio_cancel_async
Bugzilla: 1069519
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>
This is the async version of bdrv_aio_cancel, which doesn't block the
caller. It guarantees that the cb is called either before returning or
some time later.
bdrv_aio_cancel can base on bdrv_aio_cancel_async, later we can convert
all .io_cancel implementations to .io_cancel_async, and the aio_poll is
the common logic. In the end, .io_cancel can be dropped.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit 02c50efe08736116048d5fc355043080f4d5859c)
Signed-off-by: Fam Zheng <famz@redhat.com>
Downstream note:
qemu_aio_wait() is used in the busy wait loop in bdrv_aio_cancel,
because we don't have the new aio interface. Also we have to restart the
throttled queues like in bdrv_aio_co_cancel_em.
---
block.c | 24 +++++++++++++++++++++++-
block.h | 1 +
qemu-aio.h | 1 +
3 files changed, 25 insertions(+), 1 deletion(-)
Signed-off-by: Jeff E. Nelson <jen@redhat.com>
---
block.c | 24 +++++++++++++++++++++++-
block.h | 1 +
qemu-aio.h | 1 +
3 files changed, 25 insertions(+), 1 deletion(-)
diff --git a/block.c b/block.c
index d6deba2..0b1380c 100644
--- a/block.c
+++ b/block.c
@@ -3829,7 +3829,29 @@ fail:
void bdrv_aio_cancel(BlockDriverAIOCB *acb)
{
- acb->aiocb_info->cancel(acb);
+ if (acb->aiocb_info->cancel) {
+ acb->aiocb_info->cancel(acb);
+ } else {
+ BlockDriverState *bs = acb->bs;
+ qemu_aio_ref(acb);
+ bdrv_aio_cancel_async(acb);
+ while (acb->refcnt > 1) {
+ qemu_co_queue_restart_all(&bs->throttled_reqs[0]);
+ qemu_co_queue_restart_all(&bs->throttled_reqs[1]);
+ qemu_aio_wait();
+ }
+ qemu_aio_release(acb);
+ }
+}
+
+/* Async version of aio cancel. The caller is not blocked if the acb implements
+ * cancel_async, otherwise we do nothing and let the request normally complete.
+ * In either case the completion callback must be called. */
+void bdrv_aio_cancel_async(BlockDriverAIOCB *acb)
+{
+ if (acb->aiocb_info->cancel_async) {
+ acb->aiocb_info->cancel_async(acb);
+ }
}
/**************************************************************/
diff --git a/block.h b/block.h
index f9d48c3..f1db2ff 100644
--- a/block.h
+++ b/block.h
@@ -279,6 +279,7 @@ BlockDriverAIOCB *bdrv_aio_discard(BlockDriverState *bs,
int64_t sector_num, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
void bdrv_aio_cancel(BlockDriverAIOCB *acb);
+void bdrv_aio_cancel_async(BlockDriverAIOCB *acb);
typedef struct BlockRequest {
/* Fields to be filled by multiwrite caller */
diff --git a/qemu-aio.h b/qemu-aio.h
index b362263..043c857 100644
--- a/qemu-aio.h
+++ b/qemu-aio.h
@@ -23,6 +23,7 @@ typedef void BlockDriverCompletionFunc(void *opaque, int ret);
typedef struct AIOCBInfo {
void (*cancel)(BlockDriverAIOCB *acb);
+ void (*cancel_async)(BlockDriverAIOCB *acb);
size_t aiocb_size;
} AIOCBInfo;
--
2.1.0