Commit 448ad91d authored by Ming Lei's avatar Ming Lei Committed by Stefan Hajnoczi
Browse files

block: block: introduce APIs for submitting IO as a batch 



This patch introduces three APIs so that following
patches can support queuing I/O requests and submitting them
as a batch for improving I/O performance.

Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarMing Lei <ming.lei@canonical.com>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent 5a18e67d

block.c

+31 −0
Original line number Diff line number Diff line
@@ -1905,6 +1905,7 @@ void bdrv_drain_all(void) 
            bool bs_busy;



            aio_context_acquire(aio_context);

            bdrv_flush_io_queue(bs);

            bdrv_start_throttled_reqs(bs);

            bs_busy = bdrv_requests_pending(bs);

            bs_busy |= aio_poll(aio_context, bs_busy);
@@ -5782,3 +5783,33 @@ BlockDriverState *check_to_replace_node(const char *node_name, Error **errp) 


    return to_replace_bs;

}



void bdrv_io_plug(BlockDriverState *bs)

{

    BlockDriver *drv = bs->drv;

    if (drv && drv->bdrv_io_plug) {

        drv->bdrv_io_plug(bs);

    } else if (bs->file) {

        bdrv_io_plug(bs->file);

    }

}



void bdrv_io_unplug(BlockDriverState *bs)

{

    BlockDriver *drv = bs->drv;

    if (drv && drv->bdrv_io_unplug) {

        drv->bdrv_io_unplug(bs);

    } else if (bs->file) {

        bdrv_io_unplug(bs->file);

    }

}



void bdrv_flush_io_queue(BlockDriverState *bs)

{

    BlockDriver *drv = bs->drv;

    if (drv && drv->bdrv_flush_io_queue) {

        drv->bdrv_flush_io_queue(bs);

    } else if (bs->file) {

        bdrv_flush_io_queue(bs->file);

    }

}

include/block/block.h

+4 −0
Original line number Diff line number Diff line
@@ -584,4 +584,8 @@ AioContext *bdrv_get_aio_context(BlockDriverState *bs); 
 */

void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context);



void bdrv_io_plug(BlockDriverState *bs);

void bdrv_io_unplug(BlockDriverState *bs);

void bdrv_flush_io_queue(BlockDriverState *bs);



#endif

include/block/block_int.h

+5 −0
Original line number Diff line number Diff line
@@ -261,6 +261,11 @@ struct BlockDriver { 
    void (*bdrv_attach_aio_context)(BlockDriverState *bs,

                                    AioContext *new_context);



    /* io queue for linux-aio */

    void (*bdrv_io_plug)(BlockDriverState *bs);

    void (*bdrv_io_unplug)(BlockDriverState *bs);

    void (*bdrv_flush_io_queue)(BlockDriverState *bs);



    QLIST_ENTRY(BlockDriver) list;

};