Commit 61124f03 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Fam Zheng
Browse files

block: invoke .bdrv_drain callback in coroutine context and from AioContext 



This will let the callback take a CoMutex in the next patch.

Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170629132749.997-8-pbonzini@redhat.com>
Signed-off-by: default avatarFam Zheng <famz@redhat.com>
parent e7569c18

block/io.c

+33 −9
Original line number Diff line number Diff line
@@ -149,6 +149,37 @@ bool bdrv_requests_pending(BlockDriverState *bs) 
    return false;

}



typedef struct {

    Coroutine *co;

    BlockDriverState *bs;

    bool done;

} BdrvCoDrainData;



static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)

{

    BdrvCoDrainData *data = opaque;

    BlockDriverState *bs = data->bs;



    bs->drv->bdrv_co_drain(bs);



    /* Set data->done before reading bs->wakeup.  */

    atomic_mb_set(&data->done, true);

    bdrv_wakeup(bs);

}



static void bdrv_drain_invoke(BlockDriverState *bs)

{

    BdrvCoDrainData data = { .bs = bs, .done = false };



    if (!bs->drv || !bs->drv->bdrv_co_drain) {

        return;

    }



    data.co = qemu_coroutine_create(bdrv_drain_invoke_entry, &data);

    bdrv_coroutine_enter(bs, data.co);

    BDRV_POLL_WHILE(bs, !data.done);

}



static bool bdrv_drain_recurse(BlockDriverState *bs)

{

    BdrvChild *child, *tmp;
@@ -156,9 +187,8 @@ static bool bdrv_drain_recurse(BlockDriverState *bs) 


    waited = BDRV_POLL_WHILE(bs, atomic_read(&bs->in_flight) > 0);



    if (bs->drv && bs->drv->bdrv_drain) {

        bs->drv->bdrv_drain(bs);

    }

    /* Ensure any pending metadata writes are submitted to bs->file.  */

    bdrv_drain_invoke(bs);



    QLIST_FOREACH_SAFE(child, &bs->children, next, tmp) {

        BlockDriverState *bs = child->bs;
@@ -184,12 +214,6 @@ static bool bdrv_drain_recurse(BlockDriverState *bs) 
    return waited;

}



typedef struct {

    Coroutine *co;

    BlockDriverState *bs;

    bool done;

} BdrvCoDrainData;



static void bdrv_co_drain_bh_cb(void *opaque)

{

    BdrvCoDrainData *data = opaque;

block/qed.c

+3 −3
Original line number Diff line number Diff line
@@ -350,7 +350,7 @@ static void bdrv_qed_attach_aio_context(BlockDriverState *bs, 
    }

}



static void bdrv_qed_drain(BlockDriverState *bs)

static void coroutine_fn bdrv_qed_co_drain(BlockDriverState *bs)

{

    BDRVQEDState *s = bs->opaque;
@@ -359,7 +359,7 @@ static void bdrv_qed_drain(BlockDriverState *bs) 
     */

    if (s->need_check_timer && timer_pending(s->need_check_timer)) {

        qed_cancel_need_check_timer(s);

        qed_need_check_timer_cb(s);

        qed_need_check_timer_entry(s);

    }

}
@@ -1548,7 +1548,7 @@ static BlockDriver bdrv_qed = { 
    .bdrv_check               = bdrv_qed_check,

    .bdrv_detach_aio_context  = bdrv_qed_detach_aio_context,

    .bdrv_attach_aio_context  = bdrv_qed_attach_aio_context,

    .bdrv_drain               = bdrv_qed_drain,

    .bdrv_co_drain            = bdrv_qed_co_drain,

};



static void bdrv_qed_init(void)

include/block/block_int.h

+1 −1
Original line number Diff line number Diff line
@@ -324,7 +324,7 @@ struct BlockDriver { 
     * Drain and stop any internal sources of requests in the driver, and

     * remain so until next I/O callback (e.g. bdrv_co_writev) is called.

     */

    void (*bdrv_drain)(BlockDriverState *bs);

    void coroutine_fn (*bdrv_co_drain)(BlockDriverState *bs);



    void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child,

                           Error **errp);