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[Qemu-devel] [RFC][PATCH 2/9] block: Emulate AIO functions with bdrv_co_
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [RFC][PATCH 2/9] block: Emulate AIO functions with bdrv_co_readv/writev |
Date: |
Fri, 15 Jul 2011 18:47:32 +0200 |
Use the bdrv_co_readv/writev callbacks to implement bdrv_aio_readv/writev and
bdrv_read/write if a driver provides the coroutine version instead of the
synchronous or AIO version.
Signed-off-by: Kevin Wolf <address@hidden>
---
block.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 97 insertions(+), 1 deletions(-)
diff --git a/block.c b/block.c
index a57d168..79a5008 100644
--- a/block.c
+++ b/block.c
@@ -28,6 +28,7 @@
#include "block_int.h"
#include "module.h"
#include "qemu-objects.h"
+#include "qemu-coroutine.h"
#ifdef CONFIG_BSD
#include <sys/types.h>
@@ -57,6 +58,12 @@ static int bdrv_read_em(BlockDriverState *bs, int64_t
sector_num,
uint8_t *buf, int nb_sectors);
static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors);
+static BlockDriverAIOCB *bdrv_co_aio_readv_em(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+ BlockDriverCompletionFunc *cb, void *opaque);
+static BlockDriverAIOCB *bdrv_co_aio_writev_em(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+ BlockDriverCompletionFunc *cb, void *opaque);
static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
QTAILQ_HEAD_INITIALIZER(bdrv_states);
@@ -169,7 +176,13 @@ void path_combine(char *dest, int dest_size,
void bdrv_register(BlockDriver *bdrv)
{
- if (!bdrv->bdrv_aio_readv) {
+ if (bdrv->bdrv_co_readv) {
+ /* Emulate AIO by coroutines, and sync by AIO */
+ bdrv->bdrv_aio_readv = bdrv_co_aio_readv_em;
+ bdrv->bdrv_aio_writev = bdrv_co_aio_writev_em;
+ bdrv->bdrv_read = bdrv_read_em;
+ bdrv->bdrv_write = bdrv_write_em;
+ } else if (!bdrv->bdrv_aio_readv) {
/* add AIO emulation layer */
bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
@@ -2607,6 +2620,89 @@ static BlockDriverAIOCB
*bdrv_aio_writev_em(BlockDriverState *bs,
return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
}
+
+typedef struct BlockDriverAIOCBCoroutine {
+ BlockDriverAIOCB common;
+ BlockRequest req;
+ bool is_write;
+ QEMUBH* bh;
+} BlockDriverAIOCBCoroutine;
+
+static void bdrv_aio_co_cancel_em(BlockDriverAIOCB *blockacb)
+{
+ qemu_aio_flush();
+}
+
+static AIOPool bdrv_em_co_aio_pool = {
+ .aiocb_size = sizeof(BlockDriverAIOCBCoroutine),
+ .cancel = bdrv_aio_co_cancel_em,
+};
+
+static void bdrv_co_rw_bh(void *opaque)
+{
+ BlockDriverAIOCBCoroutine *acb = opaque;
+
+ acb->common.cb(acb->common.opaque, acb->req.error);
+ qemu_bh_delete(acb->bh);
+ qemu_aio_release(acb);
+}
+
+static void coroutine_fn bdrv_co_rw(void *opaque)
+{
+ BlockDriverAIOCBCoroutine *acb = opaque;
+ BlockDriverState *bs = acb->common.bs;
+
+ if (acb->is_write) {
+ acb->req.error = bs->drv->bdrv_co_readv(bs, acb->req.sector,
+ acb->req.nb_sectors, acb->req.qiov);
+ } else {
+ acb->req.error = bs->drv->bdrv_co_writev(bs, acb->req.sector,
+ acb->req.nb_sectors, acb->req.qiov);
+ }
+
+ acb->bh = qemu_bh_new(bdrv_co_rw_bh, acb);
+ qemu_bh_schedule(acb->bh);
+}
+
+static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
+ int64_t sector_num,
+ QEMUIOVector *qiov,
+ int nb_sectors,
+ BlockDriverCompletionFunc *cb,
+ void *opaque,
+ bool is_write)
+{
+ Coroutine *co;
+ BlockDriverAIOCBCoroutine *acb;
+
+ acb = qemu_aio_get(&bdrv_em_co_aio_pool, bs, cb, opaque);
+ acb->req.sector = sector_num;
+ acb->req.nb_sectors = nb_sectors;
+ acb->req.qiov = qiov;
+ acb->is_write = is_write;
+
+ co = qemu_coroutine_create(bdrv_co_rw);
+ qemu_coroutine_enter(co, acb);
+
+ return &acb->common;
+}
+
+static BlockDriverAIOCB *bdrv_co_aio_readv_em(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+ BlockDriverCompletionFunc *cb, void *opaque)
+{
+ return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque,
+ false);
+}
+
+static BlockDriverAIOCB *bdrv_co_aio_writev_em(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+ BlockDriverCompletionFunc *cb, void *opaque)
+{
+ return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque,
+ true);
+}
+
static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque)
{
--
1.7.6
- [Qemu-devel] [RFC][PATCH 0/9] Use coroutines in the block layer, Kevin Wolf, 2011/07/15
- [Qemu-devel] [RFC][PATCH 1/9] block: Add bdrv_co_readv/writev, Kevin Wolf, 2011/07/15
- [Qemu-devel] [RFC][PATCH 2/9] block: Emulate AIO functions with bdrv_co_readv/writev,
Kevin Wolf <=
- [Qemu-devel] [RFC][PATCH 3/9] block: Add bdrv_co_readv/writev emulation, Kevin Wolf, 2011/07/15
- [Qemu-devel] [RFC][PATCH 4/9] coroutines: Locks, Kevin Wolf, 2011/07/15
- [Qemu-devel] [RFC][PATCH 5/9] qcow2: Use coroutines, Kevin Wolf, 2011/07/15
- [Qemu-devel] [RFC][PATCH 6/9] qcow: Use coroutines, Kevin Wolf, 2011/07/15
- [Qemu-devel] [RFC][PATCH 8/9] coroutines: Use one global bottom half for CoQueue, Kevin Wolf, 2011/07/15
- [Qemu-devel] [RFC][PATCH 7/9] async: Remove AsyncContext, Kevin Wolf, 2011/07/15
- [Qemu-devel] [RFC][PATCH 9/9] block: Use bdrv_co_* instead of synchronous versions in coroutines, Kevin Wolf, 2011/07/15