On 08/17/2018 03:04 PM, John Snow wrote:
> Change the manual deferment to commit_complete into the implicit
> callback to job_exit, renaming commit_complete to commit_exit.
>
> This conversion does change the timing of when job_completed is
> called to after the bdrv_replace_node and bdrv_unref calls, which
> could have implications for bjob->blk which will now be put down
> after this cleanup.
>
> Kevin highlights that we did not take any permissions for that backend
> at job creation time, so it is safe to reorder these operations.
>
> Signed-off-by: John Snow <js...@redhat.com>
> ---
> block/commit.c | 20 ++++----------------
> 1 file changed, 4 insertions(+), 16 deletions(-)
>
> diff --git a/block/commit.c b/block/commit.c
> index 4a17bb73ec..93c3b6a39e 100644
> --- a/block/commit.c
> +++ b/block/commit.c
> @@ -68,19 +68,13 @@ static int coroutine_fn commit_populate(BlockBackend *bs,
> BlockBackend *base,
> return 0;
> }
>
> -typedef struct {
> - int ret;
> -} CommitCompleteData;
> -
> -static void commit_complete(Job *job, void *opaque)
> +static void commit_exit(Job *job)
> {
> CommitBlockJob *s = container_of(job, CommitBlockJob, common.job);
> BlockJob *bjob = &s->common;
> - CommitCompleteData *data = opaque;
> BlockDriverState *top = blk_bs(s->top);
> BlockDriverState *base = blk_bs(s->base);
> BlockDriverState *commit_top_bs = s->commit_top_bs;
> - int ret = data->ret;
> bool remove_commit_top_bs = false;
>
> /* Make sure commit_top_bs and top stay around until bdrv_replace_node()
> */
> @@ -93,8 +87,8 @@ static void commit_complete(Job *job, void *opaque)
>
> if (!job_is_cancelled(job) && ret == 0) {
forgot to actually squash the change in here that replaces `ret` with
`job->ret`.
> /* success */
> - ret = bdrv_drop_intermediate(s->commit_top_bs, base,
> - s->backing_file_str);
> + job->ret = bdrv_drop_intermediate(s->commit_top_bs, base,
> + s->backing_file_str);
> } else {
> /* XXX Can (or should) we somehow keep 'consistent read' blocked even
> * after the failed/cancelled commit job is gone? If we already wrote
> @@ -117,9 +111,6 @@ static void commit_complete(Job *job, void *opaque)
> * bdrv_set_backing_hd() to fail. */
> block_job_remove_all_bdrv(bjob);
>
> - job_completed(job, ret);
> - g_free(data);
> -
> /* If bdrv_drop_intermediate() didn't already do that, remove the commit
> * filter driver from the backing chain. Do this as the final step so
> that
> * the 'consistent read' permission can be granted. */
> @@ -137,7 +128,6 @@ static void commit_complete(Job *job, void *opaque)
> static int coroutine_fn commit_run(Job *job, Error **errp)
> {
> CommitBlockJob *s = container_of(job, CommitBlockJob, common.job);
> - CommitCompleteData *data;
> int64_t offset;
> uint64_t delay_ns = 0;
> int ret = 0;
> @@ -210,9 +200,6 @@ static int coroutine_fn commit_run(Job *job, Error **errp)
> out:
> qemu_vfree(buf);
>
> - data = g_malloc(sizeof(*data));
> - data->ret = ret;
> - job_defer_to_main_loop(&s->common.job, commit_complete, data);
> return ret;
> }
>
> @@ -224,6 +211,7 @@ static const BlockJobDriver commit_job_driver = {
> .user_resume = block_job_user_resume,
> .drain = block_job_drain,
> .run = commit_run,
> + .exit = commit_exit,
> },
> };
>
>
--
—js