ide/ahci: Check for -ECANCELED in aio callbacks

Before, bdrv_aio_cancel will either complete the request (like normal)
and call CB with an actual return code, or skip calling the request (for
example when the IO req is not submitted by thread pool yet).

We will change bdrv_aio_cancel to do it differently: always call CB
before return, with either [1] a normal req completion ret code, or [2]
ret == -ECANCELED. So the callers' callback must accept both cases. The
existing logic works with case [1], but not [2].

The simplest transition of callback code is do nothing in case [2], just
as if the CB is not called by the bdrv_aio_cancel() call.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
block: Add refcnt in BlockDriverAIOCB

This will be useful in synchronous cancel emulation with
bdrv_aio_cancel_async.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
block: Add bdrv_aio_cancel_async

This is the async version of bdrv_aio_cancel, which doesn't block the
caller. It guarantees that the cb is called either before returning or
some time later.

bdrv_aio_cancel can base on bdrv_aio_cancel_async, later we can convert
all .io_cancel implementations to .io_cancel_async, and the aio_poll is
the common logic. In the end, .io_cancel can be dropped.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
block: Drop bdrv_em_co_aiocb_info.cancel

Also drop the now unused ->done pointer.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
block: Drop bdrv_em_aiocb_info.cancel

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
thread-pool: Convert thread_pool_aiocb_info.cancel to cancel_async

The .cancel_async shares the same the first half with .cancel: try to
steal the request if not submitted yet. In this case set the elem to
THREAD_DONE status and ret to -ECANCELED, which means
thread_pool_completion_bh will call the cb with -ECANCELED.

If the request is already submitted, do nothing, as we know the normal
completion will happen in the future.

Testing code update:

Before, done_cb is only called if the request is already submitted by
thread pool. Now done_cb is always called, even before it is submitted,
because we emulate bdrv_aio_cancel with bdrv_aio_cancel_async. So also
update the test criteria accordingly.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
linux-aio: Convert laio_aiocb_info.cancel to .cancel_async

Just call io_cancel (2), if it fails, it means the request is not
canceled, so the event loop will eventually call
qemu_laio_process_completion.

In qemu_laio_process_completion, change to call the cb unconditionally.
It is required by bdrv_aio_cancel_async.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
dma: Convert dma_aiocb_info.cancel to .cancel_async

Just forward the request to bdrv_aio_cancel_async.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
iscsi: Convert iscsi_aiocb_info.cancel to .cancel_async

Also drop the unused field "canceled".

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
archipelago: Drop archipelago_aiocb_info.cancel

The cancelled flag is no longer useful. Later the request will complete
as before, and cb will be called.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
blkdebug: Drop blkdebug_aiocb_info.cancel

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
blkverify: Drop blkverify_aiocb_info.cancel

Also the finished pointer is not used any more.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
curl: Drop curl_aiocb_info.cancel

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
qed: Drop qed_aiocb_info.cancel

Also drop the now unused ->finished field.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
quorum: fix quorum_aio_cancel()

For a fifo read pattern, we only have one running aio (possible other cases that
has less number than num_children in the future), so we need to check if
.acb is NULL against bdrv_aio_cancel() to avoid segfault.

Cc: Eric Blake <eblake@redhat.com>
Cc: Benoit Canet <benoit@irqsave.net>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Liu Yuan <namei.unix@gmail.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
quorum: Convert quorum_aiocb_info.cancel to .cancel_async

Before, we cancel all the child requests with bdrv_aio_cancel, then free
the acb..

Now we just kick off asynchronous cancellation of child requests and
return, we know quorum_aio_cb will be called later, so in the end
quorum_aio_finalize will take care of calling the caller's cb.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
rbd: Drop rbd_aiocb_info.cancel

And also drop the now unused "cancelled" field.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
sheepdog: Convert sd_aiocb_info.cancel to .cancel_async

Also drop the now unused SheepdogAIOCB.finished field. Note that this
aio is internal to sheepdog driver and has NULL cb and opaque, and
should be unused at all.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
win32-aio: Drop win32_aiocb_info.cancel

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
ide: Convert trim_aiocb_info.cancel to .cancel_async

We know that either bh is scheduled or ide_issue_trim_cb will be called
again, so we just set i, j and ret to the right values. In both cases,
ide_trim_bh_cb will be called.

Also forward the cancellation to the iocb->aiocb which we get from
bdrv_aio_discard.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>