blockjob: introduce block-job-change QMP command

which will allow changing job-type-specific options after job
creation.

In the JobVerbTable, the same allow bits as for set-speed are used,
because set-speed can be considered an existing change command.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20231031135431.393137-2-f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/blockjob.c b/blockjob.c
index 953dc1b6dc..f0505ad232 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -330,6 +330,26 @@ static bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
     return block_job_set_speed_locked(job, speed, errp);
 }
 
+void block_job_change_locked(BlockJob *job, BlockJobChangeOptions *opts,
+                             Error **errp)
+{
+    const BlockJobDriver *drv = block_job_driver(job);
+
+    GLOBAL_STATE_CODE();
+
+    if (job_apply_verb_locked(&job->job, JOB_VERB_CHANGE, errp)) {
+        return;
+    }
+
+    if (drv->change) {
+        job_unlock();
+        drv->change(job, opts, errp);
+        job_lock();
+    } else {
+        error_setg(errp, "Job type does not support change");
+    }
+}
+
 void block_job_ratelimit_processed_bytes(BlockJob *job, uint64_t n)
 {
     IO_CODE();