On Wed, Apr 08, 2020 at 12:30:47PM +0300, Vladimir Sementsov-Ogievskiy wrote: > It's safer to expand in_flight request to start before enter to
Please explain what exeactly "safer" means. If I understand correctly
this is just a refactoring and does not fix bugs that have been hit in
the real world.
Is this just a generate attempt to avoid accidentally performing
operations that need to happen as part of the request after the dec
call?
> @@ -2718,17 +2746,18 @@ bdrv_co_rw_vmstate(BlockDriverState *bs, QEMUIOVector
> *qiov, int64_t pos,
> ret = drv->bdrv_save_vmstate(bs, qiov, pos);
> }
> } else if (bs->file) {
> - ret = bdrv_co_rw_vmstate(bs->file->bs, qiov, pos, is_read);
> + bdrv_inc_in_flight(bs->file->bs);
> + ret = bdrv_do_rw_vmstate(bs->file->bs, qiov, pos, is_read);
> + bdrv_dec_in_flight(bs->file->bs);
Here we inc/dec...
> }
>
> - bdrv_dec_in_flight(bs);
> return ret;
> }
>
> static void coroutine_fn bdrv_co_rw_vmstate_entry(void *opaque)
> {
> BdrvVmstateCo *co = opaque;
> - co->ret = bdrv_co_rw_vmstate(co->bs, co->qiov, co->pos, co->is_read);
> + co->ret = bdrv_do_rw_vmstate(co->bs, co->qiov, co->pos, co->is_read);
...here we don't. The code is correct, but bdrv_co_rw_vmstate_entry()
should also document that its caller must inc/dec.
> @@ -2950,7 +2994,7 @@ static void coroutine_fn bdrv_flush_co_entry(void
> *opaque)
> {
> FlushCo *rwco = opaque;
>
> - rwco->ret = bdrv_co_flush(rwco->bs);
> + rwco->ret = bdrv_do_flush(rwco->bs);
> aio_wait_kick();
> }
This function should also document that the caller must inc/dec.
signature.asc
Description: PGP signature
