Re: [PATCH 1/6] writeback: fix writeback completion notifications

[Jan Kara <jack@suse.cz>]

On Tue 08-06-10 18:14:34, Christoph Hellwig wrote:
> The code dealing with bdi_work->state and completion of a bdi_work is a
> major mess currently.  This patch makes sure we directly use one set of
> flags to deal with it, and use it consistently, which means:
> 
>  - always notify about completion from the rcu callback.  We only ever
>    wait for it from on-stack callers, so this simplification does not
>    even cause a theoretical slowdown currently.  It also makes sure we
>    don't miss out on the notification if we ever add other callers to
>    wait for it.
>  - make earlier completion notification depending on the on-stack
>    allocation, not the sync mode.  If we introduce new callers that
>    want to do WB_SYNC_NONE writeback from on-stack callers this will
>    be nessecary.
> 
> Also rename bdi_wait_on_work_clear to bdi_wait_on_work_done and inline
  What I find slightly misleading on bdi_wait_on_work_done is that work
isn't always "done" when this returns. For WB_SYNC_NONE writeback this
function returns as soon as writeback thread starts the work... But I don't
have a better name.

								Honza

-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR