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block: remove unused BLOCK_OP_TYPE_DATAPLANE

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BLOCK_OP_TYPE_DATAPLANE prevents BlockDriverState from being used by
virtio-blk/virtio-scsi with IOThread. Commit b112a65c52aa ("block:
declare blockjobs and dataplane friends!") eliminated the main reason
for this blocker in 2014.

Nowadays the block layer supports I/O from multiple AioContexts, so
there is even less reason to block IOThread users. Any legitimate
reasons related to interference would probably also apply to
non-IOThread users.

The only remaining users are bdrv_op_unblock(BLOCK_OP_TYPE_DATAPLANE)
calls after bdrv_op_block_all(). If we remove BLOCK_OP_TYPE_DATAPLANE
their behavior doesn't change.

Existing bdrv_op_block_all() callers that don't explicitly unblock
BLOCK_OP_TYPE_DATAPLANE seem to do so simply because no one bothered to
rather than because it is necessary to keep BLOCK_OP_TYPE_DATAPLANE
blocked.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20250203182529.269066-1-stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2025-02-03 13:25:29 -05:00 committed by Kevin Wolf
parent bbf105ef3c
commit fc4e394b28
5 changed files with 0 additions and 16 deletions
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1
block/replication.c
View File

@ -576,7 +576,6 @@ static void replication_start(ReplicationState *rs, ReplicationMode mode,
return;
}
bdrv_op_block_all(top_bs, s->blocker);
bdrv_op_unblock(top_bs, BLOCK_OP_TYPE_DATAPLANE, s->blocker);
bdrv_graph_wrunlock();

2
blockjob.c
View File

@ -539,8 +539,6 @@ void *block_job_create(const char *job_id, const BlockJobDriver *driver,
goto fail;
}
bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
if (!block_job_set_speed(job, speed, errp)) {
goto fail;
}

9
hw/block/virtio-blk.c
View File

@ -1562,15 +1562,6 @@ static bool virtio_blk_vq_aio_context_init(VirtIOBlock *s, Error **errp)
error_setg(errp, "ioeventfd is required for iothread");
return false;
}
/*
* If ioeventfd is (re-)enabled while the guest is running there could
* be block jobs that can conflict.
*/
if (blk_op_is_blocked(conf->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
error_prepend(errp, "cannot start virtio-blk ioeventfd: ");
return false;
}
}
s->vq_aio_context = g_new(AioContext *, conf->num_queues);

3
hw/scsi/virtio-scsi.c
View File

@ -1065,9 +1065,6 @@ static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
int ret;
if (s->ctx && !s->dataplane_fenced) {
if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
return;
}
ret = blk_set_aio_context(sd->conf.blk, s->ctx, errp);
if (ret < 0) {
return;

1
include/block/block-common.h
View File

@ -356,7 +356,6 @@ typedef enum BlockOpType {
BLOCK_OP_TYPE_CHANGE,
BLOCK_OP_TYPE_COMMIT_SOURCE,
BLOCK_OP_TYPE_COMMIT_TARGET,
BLOCK_OP_TYPE_DATAPLANE,
BLOCK_OP_TYPE_DRIVE_DEL,
BLOCK_OP_TYPE_EJECT,
BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,