mirror: Drop s->synced

As of HEAD^, there is no meaning to s->synced other than whether the job
is READY or not.  job_is_ready() gives us that information, too.

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20211006151940.214590-4-hreitz@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

block/mirror.c

@@ -56,7 +56,6 @@ typedef struct MirrorBlockJob {
     bool zero_target;
     MirrorCopyMode copy_mode;
     BlockdevOnError on_source_error, on_target_error;
-    bool synced;
     /* Set when the target is synced (dirty bitmap is clean, nothing
      * in flight) and the job is running in active mode */
     bool actively_synced;
@@ -943,7 +942,6 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
     if (s->bdev_length == 0) {
         /* Transition to the READY state and wait for complete. */
         job_transition_to_ready(&s->common.job);
-        s->synced = true;
         s->actively_synced = true;
         while (!job_is_cancelled(&s->common.job) && !s->should_complete) {
             job_yield(&s->common.job);
@@ -1035,7 +1033,7 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
         should_complete = false;
         if (s->in_flight == 0 && cnt == 0) {
             trace_mirror_before_flush(s);
-            if (!s->synced) {
+            if (!job_is_ready(&s->common.job)) {
                 if (mirror_flush(s) < 0) {
                     /* Go check s->ret.  */
                     continue;
@@ -1046,7 +1044,6 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
                  * the target in a consistent state.
                  */
                 job_transition_to_ready(&s->common.job);
-                s->synced = true;
                 if (s->copy_mode != MIRROR_COPY_MODE_BACKGROUND) {
                     s->actively_synced = true;
                 }
@@ -1090,14 +1087,15 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
 
         ret = 0;
 
-        if (s->synced && !should_complete) {
+        if (job_is_ready(&s->common.job) && !should_complete) {
             delay_ns = (s->in_flight == 0 &&
                         cnt == 0 ? BLOCK_JOB_SLICE_TIME : 0);
         }
-        trace_mirror_before_sleep(s, cnt, s->synced, delay_ns);
+        trace_mirror_before_sleep(s, cnt, job_is_ready(&s->common.job),
+                                  delay_ns);
         job_sleep_ns(&s->common.job, delay_ns);
         if (job_is_cancelled(&s->common.job) &&
-            (!s->synced || s->common.job.force_cancel))
+            (!job_is_ready(&s->common.job) || s->common.job.force_cancel))
         {
             break;
         }
@@ -1110,8 +1108,9 @@ immediate_exit:
          * or it was cancelled prematurely so that we do not guarantee that
          * the target is a copy of the source.
          */
-        assert(ret < 0 || ((s->common.job.force_cancel || !s->synced) &&
-               job_is_cancelled(&s->common.job)));
+        assert(ret < 0 ||
+               ((s->common.job.force_cancel || !job_is_ready(&s->common.job)) &&
+                job_is_cancelled(&s->common.job)));
         assert(need_drain);
         mirror_wait_for_all_io(s);
     }
@@ -1134,7 +1133,7 @@ static void mirror_complete(Job *job, Error **errp)
 {
     MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job);
 
-    if (!s->synced) {
+    if (!job_is_ready(job)) {
         error_setg(errp, "The active block job '%s' cannot be completed",
                    job->id);
         return;