On Tue, Aug 09, 2011 at 12:17:50PM +0800, Zhi Yong Wu wrote:
> The patch introduce one block queue for QEMU block layer.
>
> Signed-off-by: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx>
> ---
> block/blk-queue.c | 141 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> block/blk-queue.h | 73 +++++++++++++++++++++++++++
> 2 files changed, 214 insertions(+), 0 deletions(-)
> create mode 100644 block/blk-queue.c
> create mode 100644 block/blk-queue.h
>
> diff --git a/block/blk-queue.c b/block/blk-queue.c
> new file mode 100644
> index 0000000..f36f3e2
> --- /dev/null
> +++ b/block/blk-queue.c
> @@ -0,0 +1,141 @@
> +/*
> + * QEMU System Emulator queue definition for block layer
> + *
> + * Copyright (c) 2011 Zhi Yong Wu <zwu.kernel@xxxxxxxxx>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#include "block_int.h"
> +#include "qemu-queue.h"
> +#include "block/blk-queue.h"
> +
> +/* The APIs for block request queue on qemu block layer.
> + */
> +
> +static void qemu_block_queue_cancel(BlockDriverAIOCB *acb)
> +{
> + qemu_aio_release(acb);
> +}
> +
> +static AIOPool block_queue_pool = {
> + .aiocb_size = sizeof(struct BlockDriverAIOCB),
> + .cancel = qemu_block_queue_cancel,
> +};
> +
> +static void qemu_block_queue_callback(void *opaque, int ret)
> +{
> + BlockDriverAIOCB *acb = opaque;
> +
> + qemu_aio_release(acb);
> +}
> +
> +BlockQueue *qemu_new_block_queue(void)
> +{
> + BlockQueue *queue;
> +
> + queue = qemu_mallocz(sizeof(BlockQueue));
> +
> + QTAILQ_INIT(&queue->requests);
> +
> + return queue;
> +}
> +
> +void qemu_del_block_queue(BlockQueue *queue)
> +{
> + BlockIORequest *request, *next;
> +
> + QTAILQ_FOREACH_SAFE(request, &queue->requests, entry, next) {
> + QTAILQ_REMOVE(&queue->requests, request, entry);
> + qemu_free(request);
> + }
> +
> + qemu_free(queue);
> +}
> +
> +BlockDriverAIOCB *qemu_block_queue_enqueue(BlockQueue *queue,
> + BlockDriverState *bs,
> + BlockRequestHandler *handler,
> + int64_t sector_num,
> + QEMUIOVector *qiov,
> + int nb_sectors,
> + BlockDriverCompletionFunc *cb,
> + void *opaque)
> +{
> + BlockIORequest *request;
> + BlockDriverAIOCB *acb;
> +
> + request = qemu_malloc(sizeof(BlockIORequest));
> + request->bs = bs;
> + request->handler = handler;
> + request->sector_num = sector_num;
> + request->qiov = qiov;
> + request->nb_sectors = nb_sectors;
> + request->cb = cb;
> + request->opaque = opaque;
> +
> + QTAILQ_INSERT_TAIL(&queue->requests, request, entry);
> +
> + acb = qemu_aio_get(&block_queue_pool, bs,
> + qemu_block_queue_callback, opaque);
> +
> + request->acb = acb;
> +
> + return acb;
> +}
> +
> +int qemu_block_queue_handler(BlockIORequest *request)
> +{
> + int ret;
> + BlockDriverAIOCB *res;
> +
> + /* indicate this req is from block queue */
> + request->bs->req_from_queue = true;
> +
> + res = request->handler(request->bs, request->sector_num,
> + request->qiov, request->nb_sectors,
> + request->cb, request->opaque);
should'nt you return with a failure here if res == NULL?
Otherwise qemu_block_queue_callback() gets called which
will release the acb.
> +
> + if (request->acb) {
> + qemu_block_queue_callback(request->acb, 0);
> + }
> +
> + ret = (res == NULL) ? 0 : 1;
> +
> + return ret;
> +}
RP
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