On 03/23/2017 01:39 PM, Paolo Bonzini wrote:
> Outside blockjob.c, block_job_unref is only used when a block job fails
> to start, and block_job_ref is not used at all. The reference counting
> thus is pretty well hidden. Introduce a separate function to be used
> by block jobs; because block_job_ref and block_job_unref now become
> static, move them earlier in blockjob.c.
>
Early into the series, "I guess so."
It makes it a lot less obvious and more vague as to what exactly is
happening here, so I like it less.
> Later on, block_job_fail will also have different locking than
> block_job_unref.
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
> block/backup.c | 2 +-
> block/commit.c | 2 +-
> block/mirror.c | 2 +-
> blockjob.c | 47
> ++++++++++++++++++++++++++------------------
> include/block/blockjob_int.h | 15 +++-----------
> tests/test-blockjob.c | 10 +++++-----
> 6 files changed, 39 insertions(+), 39 deletions(-)
>
> diff --git a/block/backup.c b/block/backup.c
> index a4fb288..f284fd5 100644
> --- a/block/backup.c
> +++ b/block/backup.c
> @@ -692,7 +692,7 @@ BlockJob *backup_job_create(const char *job_id,
> BlockDriverState *bs,
> }
> if (job) {
> backup_clean(&job->common);
> - block_job_unref(&job->common);
> + block_job_fail(&job->common);
> }
>
> return NULL;
> diff --git a/block/commit.c b/block/commit.c
> index 2832482..9b9ea39 100644
> --- a/block/commit.c
> +++ b/block/commit.c
> @@ -424,7 +424,7 @@ fail:
> if (commit_top_bs) {
> bdrv_set_backing_hd(overlay_bs, top, &error_abort);
> }
> - block_job_unref(&s->common);
> + block_job_fail(&s->common);
> }
>
>
> diff --git a/block/mirror.c b/block/mirror.c
> index ca4baa5..5cb2134 100644
> --- a/block/mirror.c
> +++ b/block/mirror.c
> @@ -1243,7 +1243,7 @@ fail:
> if (s) {
> g_free(s->replaces);
> blk_unref(s->target);
> - block_job_unref(&s->common);
> + block_job_fail(&s->common);
> }
>
> bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL,
> diff --git a/blockjob.c b/blockjob.c
> index 24d1e12..1c63d15 100644
> --- a/blockjob.c
> +++ b/blockjob.c
> @@ -106,6 +106,32 @@ BlockJob *block_job_get(const char *id)
> return NULL;
> }
>
> +static void block_job_ref(BlockJob *job)
> +{
> + ++job->refcnt;
> +}
> +
> +static void block_job_attached_aio_context(AioContext *new_context,
> + void *opaque);
> +static void block_job_detach_aio_context(void *opaque);
> +
^ Some tagalongs to the party?
> +static void block_job_unref(BlockJob *job)
> +{
> + if (--job->refcnt == 0) {
> + BlockDriverState *bs = blk_bs(job->blk);
> + bs->job = NULL;
> + block_job_remove_all_bdrv(job);
> + blk_remove_aio_context_notifier(job->blk,
> + block_job_attached_aio_context,
> + block_job_detach_aio_context, job);
> + blk_unref(job->blk);
> + error_free(job->blocker);
> + g_free(job->id);
> + QLIST_REMOVE(job, job_list);
> + g_free(job);
> + }
> +}
> +
> static void block_job_attached_aio_context(AioContext *new_context,
> void *opaque)
> {
> @@ -293,26 +319,9 @@ void block_job_start(BlockJob *job)
> qemu_coroutine_enter(job->co);
> }
>
> -void block_job_ref(BlockJob *job)
> -{
> - ++job->refcnt;
> -}
> -
> -void block_job_unref(BlockJob *job)
> +void block_job_fail(BlockJob *job)
> {
> - if (--job->refcnt == 0) {
> - BlockDriverState *bs = blk_bs(job->blk);
> - bs->job = NULL;
> - block_job_remove_all_bdrv(job);
> - blk_remove_aio_context_notifier(job->blk,
> - block_job_attached_aio_context,
> - block_job_detach_aio_context, job);
> - blk_unref(job->blk);
> - error_free(job->blocker);
> - g_free(job->id);
> - QLIST_REMOVE(job, job_list);
> - g_free(job);
> - }
> + block_job_unref(job);
> }
>
> static void block_job_completed_single(BlockJob *job)
> diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h
> index bfcc5d1..97ffc43 100644
> --- a/include/block/blockjob_int.h
> +++ b/include/block/blockjob_int.h
> @@ -156,21 +156,12 @@ void block_job_sleep_ns(BlockJob *job, QEMUClockType
> type, int64_t ns);
> void block_job_yield(BlockJob *job);
>
> /**
> - * block_job_ref:
> + * block_job_fail:
> * @bs: The block device.
> *
> - * Grab a reference to the block job. Should be paired with block_job_unref.
> + * The block job could not be started, free it.
> */
> -void block_job_ref(BlockJob *job);
> -
> -/**
> - * block_job_unref:
> - * @bs: The block device.
> - *
> - * Release reference to the block job and release resources if it is the last
> - * reference.
> - */
> -void block_job_unref(BlockJob *job);
> +void block_job_fail(BlockJob *job);
>
> /**
> * block_job_completed:
> diff --git a/tests/test-blockjob.c b/tests/test-blockjob.c
> index 740e740..35bbbbc 100644
> --- a/tests/test-blockjob.c
> +++ b/tests/test-blockjob.c
> @@ -116,11 +116,11 @@ static void test_job_ids(void)
> job[1] = do_test_id(blk[1], "id0", false);
>
> /* But once job[0] finishes we can reuse its ID */
> - block_job_unref(job[0]);
> + block_job_fail(job[0]);
> job[1] = do_test_id(blk[1], "id0", true);
>
> /* No job ID specified, defaults to the backend name ('drive1') */
> - block_job_unref(job[1]);
> + block_job_fail(job[1]);
> job[1] = do_test_id(blk[1], NULL, true);
>
> /* Duplicate job ID */
> @@ -133,9 +133,9 @@ static void test_job_ids(void)
> /* This one is valid */
> job[2] = do_test_id(blk[2], "id_2", true);
>
> - block_job_unref(job[0]);
> - block_job_unref(job[1]);
> - block_job_unref(job[2]);
> + block_job_fail(job[0]);
> + block_job_fail(job[1]);
> + block_job_fail(job[2]);
>
> destroy_blk(blk[0]);
> destroy_blk(blk[1]);
>
Mechanically OK, of course. Allow me to discover my appetite for it
further into your series.
