[PATCH v3 10/16] jobs: protect jobs with job_lock/unlock

[Emanuele Giuseppe Esposito <eesposit@redhat.com>]

Introduce the job locking mechanism through the whole job API,
following the comments and requirements of job-monitor (assume
lock is held) and job-driver (lock is not held).

job_{lock/unlock} is independent from real_job_{lock/unlock}.

Note: at this stage, job_{lock/unlock} and job lock guard macros
are *nop*.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
 block.c             |  18 +++---
 block/replication.c |   8 ++-
 blockdev.c          |  17 +++++-
 blockjob.c          |  64 ++++++++++++++-------
 job-qmp.c           |   2 +
 job.c               | 132 +++++++++++++++++++++++++++++++-------------
 monitor/qmp-cmds.c  |   6 +-
 qemu-img.c          |  41 ++++++++------
 8 files changed, 199 insertions(+), 89 deletions(-)

diff --git a/block.c b/block.c
index 8fcd525fa0..fac0759422 100644
--- a/block.c
+++ b/block.c
@@ -4976,7 +4976,9 @@ static void bdrv_close(BlockDriverState *bs)
 
 void bdrv_close_all(void)
 {
-    assert(job_next_locked(NULL) == NULL);
+    WITH_JOB_LOCK_GUARD() {
+        assert(job_next_locked(NULL) == NULL);
+    }
     assert(qemu_in_main_thread());
 
     /* Drop references from requests still in flight, such as canceled block
@@ -6154,13 +6156,15 @@ XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp)
         }
     }
 
-    for (job = block_job_next(NULL); job; job = block_job_next(job)) {
-        GSList *el;
+    WITH_JOB_LOCK_GUARD() {
+        for (job = block_job_next(NULL); job; job = block_job_next(job)) {
+            GSList *el;
 
-        xdbg_graph_add_node(gr, job, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_JOB,
-                           job->job.id);
-        for (el = job->nodes; el; el = el->next) {
-            xdbg_graph_add_edge(gr, job, (BdrvChild *)el->data);
+            xdbg_graph_add_node(gr, job, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_JOB,
+                                job->job.id);
+            for (el = job->nodes; el; el = el->next) {
+                xdbg_graph_add_edge(gr, job, (BdrvChild *)el->data);
+            }
         }
     }
 
diff --git a/block/replication.c b/block/replication.c
index 5215c328c1..50ea778937 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -149,7 +149,9 @@ static void replication_close(BlockDriverState *bs)
     if (s->stage == BLOCK_REPLICATION_FAILOVER) {
         commit_job = &s->commit_job->job;
         assert(commit_job->aio_context == qemu_get_current_aio_context());
-        job_cancel_sync_locked(commit_job, false);
+        WITH_JOB_LOCK_GUARD() {
+            job_cancel_sync_locked(commit_job, false);
+        }
     }
 
     if (s->mode == REPLICATION_MODE_SECONDARY) {
@@ -726,7 +728,9 @@ static void replication_stop(ReplicationState *rs, bool failover, Error **errp)
          * disk, secondary disk in backup_job_completed().
          */
         if (s->backup_job) {
-            job_cancel_sync_locked(&s->backup_job->job, true);
+            WITH_JOB_LOCK_GUARD() {
+                job_cancel_sync_locked(&s->backup_job->job, true);
+            }
         }
 
         if (!failover) {
diff --git a/blockdev.c b/blockdev.c
index ee35aff13a..099d57e0d2 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -155,6 +155,8 @@ void blockdev_mark_auto_del(BlockBackend *blk)
         return;
     }
 
+    JOB_LOCK_GUARD();
+
     for (job = block_job_next(NULL); job; job = block_job_next(job)) {
         if (block_job_has_bdrv(job, blk_bs(blk))) {
             AioContext *aio_context = job->job.aio_context;
@@ -1832,7 +1834,9 @@ static void drive_backup_abort(BlkActionState *common)
         aio_context = bdrv_get_aio_context(state->bs);
         aio_context_acquire(aio_context);
 
-        job_cancel_sync_locked(&state->job->job, true);
+        WITH_JOB_LOCK_GUARD() {
+            job_cancel_sync_locked(&state->job->job, true);
+        }
 
         aio_context_release(aio_context);
     }
@@ -1933,7 +1937,9 @@ static void blockdev_backup_abort(BlkActionState *common)
         aio_context = bdrv_get_aio_context(state->bs);
         aio_context_acquire(aio_context);
 
-        job_cancel_sync_locked(&state->job->job, true);
+        WITH_JOB_LOCK_GUARD() {
+            job_cancel_sync_locked(&state->job->job, true);
+        }
 
         aio_context_release(aio_context);
     }
@@ -2382,7 +2388,10 @@ exit:
     if (!has_props) {
         qapi_free_TransactionProperties(props);
     }
-    job_txn_unref_locked(block_job_txn);
+
+    WITH_JOB_LOCK_GUARD() {
+        job_txn_unref_locked(block_job_txn);
+    }
 }
 
 BlockDirtyBitmapSha256 *qmp_x_debug_block_dirty_bitmap_sha256(const char *node,
@@ -3705,6 +3714,8 @@ BlockJobInfoList *qmp_query_block_jobs(Error **errp)
     BlockJobInfoList *head = NULL, **tail = &head;
     BlockJob *job;
 
+    JOB_LOCK_GUARD();
+
     for (job = block_job_next(NULL); job; job = block_job_next(job)) {
         BlockJobInfo *value;
 
diff --git a/blockjob.c b/blockjob.c
index ce356be51e..e00c8d31d5 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -88,7 +88,9 @@ static char *child_job_get_parent_desc(BdrvChild *c)
 static void child_job_drained_begin(BdrvChild *c)
 {
     BlockJob *job = c->opaque;
-    job_pause_locked(&job->job);
+    WITH_JOB_LOCK_GUARD() {
+        job_pause_locked(&job->job);
+    }
 }
 
 static bool child_job_drained_poll(BdrvChild *c)
@@ -100,8 +102,10 @@ static bool child_job_drained_poll(BdrvChild *c)
     /* An inactive or completed job doesn't have any pending requests. Jobs
      * with !job->busy are either already paused or have a pause point after
      * being reentered, so no job driver code will run before they pause. */
-    if (!job->busy || job_is_completed_locked(job)) {
-        return false;
+    WITH_JOB_LOCK_GUARD() {
+        if (!job->busy || job_is_completed_locked(job)) {
+            return false;
+        }
     }
 
     /* Otherwise, assume that it isn't fully stopped yet, but allow the job to
@@ -116,7 +120,9 @@ static bool child_job_drained_poll(BdrvChild *c)
 static void child_job_drained_end(BdrvChild *c, int *drained_end_counter)
 {
     BlockJob *job = c->opaque;
-    job_resume_locked(&job->job);
+    WITH_JOB_LOCK_GUARD() {
+        job_resume_locked(&job->job);
+    }
 }
 
 static bool child_job_can_set_aio_ctx(BdrvChild *c, AioContext *ctx,
@@ -238,7 +244,13 @@ int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs,
 
 static void block_job_on_idle(Notifier *n, void *opaque)
 {
+    /*
+     * we can't kick with job_mutex held, but we also want
+     * to protect the notifier list.
+     */
+    job_unlock();
     aio_wait_kick();
+    job_lock();
 }
 
 bool block_job_is_internal(BlockJob *job)
@@ -278,7 +290,9 @@ bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
     job->speed = speed;
 
     if (drv->set_speed) {
+        job_unlock();
         drv->set_speed(job, speed);
+        job_lock();
     }
 
     if (speed && speed <= old_speed) {
@@ -458,13 +472,15 @@ void *block_job_create(const char *job_id, const BlockJobDriver *driver,
     job->ready_notifier.notify = block_job_event_ready;
     job->idle_notifier.notify = block_job_on_idle;
 
-    notifier_list_add(&job->job.on_finalize_cancelled,
-                      &job->finalize_cancelled_notifier);
-    notifier_list_add(&job->job.on_finalize_completed,
-                      &job->finalize_completed_notifier);
-    notifier_list_add(&job->job.on_pending, &job->pending_notifier);
-    notifier_list_add(&job->job.on_ready, &job->ready_notifier);
-    notifier_list_add(&job->job.on_idle, &job->idle_notifier);
+    WITH_JOB_LOCK_GUARD() {
+        notifier_list_add(&job->job.on_finalize_cancelled,
+                          &job->finalize_cancelled_notifier);
+        notifier_list_add(&job->job.on_finalize_completed,
+                          &job->finalize_completed_notifier);
+        notifier_list_add(&job->job.on_pending, &job->pending_notifier);
+        notifier_list_add(&job->job.on_ready, &job->ready_notifier);
+        notifier_list_add(&job->job.on_idle, &job->idle_notifier);
+    }
 
     error_setg(&job->blocker, "block device is in use by block job: %s",
                job_type_str(&job->job));
@@ -477,11 +493,14 @@ void *block_job_create(const char *job_id, const BlockJobDriver *driver,
     blk_set_disable_request_queuing(blk, true);
     blk_set_allow_aio_context_change(blk, true);
 
-    if (!block_job_set_speed(job, speed, errp)) {
-        job_early_fail(&job->job);
-        return NULL;
+    WITH_JOB_LOCK_GUARD() {
+        if (!block_job_set_speed(job, speed, errp)) {
+            job_early_fail_locked(&job->job);
+            return NULL;
+        }
     }
 
+
     return job;
 }
 
@@ -499,7 +518,9 @@ void block_job_user_resume(Job *job)
 {
     BlockJob *bjob = container_of(job, BlockJob, job);
     assert(qemu_in_main_thread());
-    block_job_iostatus_reset(bjob);
+    WITH_JOB_LOCK_GUARD() {
+        block_job_iostatus_reset(bjob);
+    }
 }
 
 BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err,
@@ -532,10 +553,15 @@ BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err,
                                         action);
     }
     if (action == BLOCK_ERROR_ACTION_STOP) {
-        if (!job->job.user_paused) {
-            job_pause_locked(&job->job);
-            /* make the pause user visible, which will be resumed from QMP. */
-            job->job.user_paused = true;
+        WITH_JOB_LOCK_GUARD() {
+            if (!job->job.user_paused) {
+                job_pause_locked(&job->job);
+                /*
+                 * make the pause user visible, which will be
+                 * resumed from QMP.
+                 */
+                job->job.user_paused = true;
+            }
         }
         block_job_iostatus_set_err(job, error);
     }
diff --git a/job-qmp.c b/job-qmp.c
index f6f9840436..9fa14bf761 100644
--- a/job-qmp.c
+++ b/job-qmp.c
@@ -171,6 +171,8 @@ JobInfoList *qmp_query_jobs(Error **errp)
     JobInfoList *head = NULL, **tail = &head;
     Job *job;
 
+    JOB_LOCK_GUARD();
+
     for (job = job_next_locked(NULL); job; job = job_next_locked(job)) {
         JobInfo *value;
 
diff --git a/job.c b/job.c
index 2ee7233763..56722a5043 100644
--- a/job.c
+++ b/job.c
@@ -394,6 +394,8 @@ void *job_create(const char *job_id, const JobDriver *driver, JobTxn *txn,
 {
     Job *job;
 
+    JOB_LOCK_GUARD();
+
     if (job_id) {
         if (flags & JOB_INTERNAL) {
             error_setg(errp, "Cannot specify job ID for internal job");
@@ -467,7 +469,9 @@ void job_unref_locked(Job *job)
         assert(!job->txn);
 
         if (job->driver->free) {
+            job_unlock();
             job->driver->free(job);
+            job_lock();
         }
 
         QLIST_REMOVE(job, job_list);
@@ -551,11 +555,14 @@ void job_enter_cond_locked(Job *job, bool(*fn)(Job *job))
     timer_del(&job->sleep_timer);
     job->busy = true;
     real_job_unlock();
+    job_unlock();
     aio_co_enter(job->aio_context, job->co);
+    job_lock();
 }
 
 void job_enter(Job *job)
 {
+    JOB_LOCK_GUARD();
     job_enter_cond_locked(job, NULL);
 }
 
@@ -574,7 +581,9 @@ static void coroutine_fn job_do_yield(Job *job, uint64_t ns)
     job->busy = false;
     job_event_idle(job);
     real_job_unlock();
+    job_unlock();
     qemu_coroutine_yield();
+    job_lock();
 
     /* Set by job_enter_cond_locked() before re-entering the coroutine.  */
     assert(job->busy);
@@ -584,18 +593,23 @@ void coroutine_fn job_pause_point(Job *job)
 {
     assert(job && job_started(job));
 
+    job_lock();
     if (!job_should_pause(job)) {
+        job_unlock();
         return;
     }
-    if (job_is_cancelled(job)) {
+    if (job_is_cancelled_locked(job)) {
+        job_unlock();
         return;
     }
 
     if (job->driver->pause) {
+        job_unlock();
         job->driver->pause(job);
+        job_lock();
     }
 
-    if (job_should_pause(job) && !job_is_cancelled(job)) {
+    if (job_should_pause(job) && !job_is_cancelled_locked(job)) {
         JobStatus status = job->status;
         job_state_transition(job, status == JOB_STATUS_READY
                                   ? JOB_STATUS_STANDBY
@@ -605,6 +619,7 @@ void coroutine_fn job_pause_point(Job *job)
         job->paused = false;
         job_state_transition(job, status);
     }
+    job_unlock();
 
     if (job->driver->resume) {
         job->driver->resume(job);
@@ -613,15 +628,17 @@ void coroutine_fn job_pause_point(Job *job)
 
 void job_yield(Job *job)
 {
-    assert(job->busy);
+    WITH_JOB_LOCK_GUARD() {
+        assert(job->busy);
 
-    /* Check cancellation *before* setting busy = false, too!  */
-    if (job_is_cancelled(job)) {
-        return;
-    }
+        /* Check cancellation *before* setting busy = false, too!  */
+        if (job_is_cancelled_locked(job)) {
+            return;
+        }
 
-    if (!job_should_pause(job)) {
-        job_do_yield(job, -1);
+        if (!job_should_pause(job)) {
+            job_do_yield(job, -1);
+        }
     }
 
     job_pause_point(job);
@@ -629,21 +646,23 @@ void job_yield(Job *job)
 
 void coroutine_fn job_sleep_ns(Job *job, int64_t ns)
 {
-    assert(job->busy);
+    WITH_JOB_LOCK_GUARD() {
+        assert(job->busy);
 
-    /* Check cancellation *before* setting busy = false, too!  */
-    if (job_is_cancelled(job)) {
-        return;
-    }
+        /* Check cancellation *before* setting busy = false, too!  */
+        if (job_is_cancelled_locked(job)) {
+            return;
+        }
 
-    if (!job_should_pause(job)) {
-        job_do_yield(job, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + ns);
+        if (!job_should_pause(job)) {
+            job_do_yield(job, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + ns);
+        }
     }
 
     job_pause_point(job);
 }
 
-/* Assumes the block_job_mutex is held */
+/* Assumes the job_mutex is held */
 static bool job_timer_not_pending(Job *job)
 {
     return !timer_pending(&job->sleep_timer);
@@ -653,7 +672,7 @@ void job_pause_locked(Job *job)
 {
     job->pause_count++;
     if (!job->paused) {
-        job_enter(job);
+        job_enter_cond_locked(job, NULL);
     }
 }
 
@@ -699,7 +718,9 @@ void job_user_resume_locked(Job *job, Error **errp)
         return;
     }
     if (job->driver->user_resume) {
+        job_unlock();
         job->driver->user_resume(job);
+        job_lock();
     }
     job->user_paused = false;
     job_resume_locked(job);
@@ -753,7 +774,7 @@ static void job_conclude(Job *job)
 
 static void job_update_rc(Job *job)
 {
-    if (!job->ret && job_is_cancelled(job)) {
+    if (!job->ret && job_is_cancelled_locked(job)) {
         job->ret = -ECANCELED;
     }
     if (job->ret) {
@@ -769,7 +790,9 @@ static void job_commit(Job *job)
     assert(!job->ret);
     assert(qemu_in_main_thread());
     if (job->driver->commit) {
+        job_unlock();
         job->driver->commit(job);
+        job_lock();
     }
 }
 
@@ -778,7 +801,9 @@ static void job_abort(Job *job)
     assert(job->ret);
     assert(qemu_in_main_thread());
     if (job->driver->abort) {
+        job_unlock();
         job->driver->abort(job);
+        job_lock();
     }
 }
 
@@ -786,12 +811,15 @@ static void job_clean(Job *job)
 {
     assert(qemu_in_main_thread());
     if (job->driver->clean) {
+        job_unlock();
         job->driver->clean(job);
+        job_lock();
     }
 }
 
 static int job_finalize_single(Job *job)
 {
+    int job_ret;
     AioContext *ctx = job->aio_context;
 
     assert(job_is_completed_locked(job));
@@ -811,12 +839,15 @@ static int job_finalize_single(Job *job)
     aio_context_release(ctx);
 
     if (job->cb) {
-        job->cb(job->opaque, job->ret);
+        job_ret = job->ret;
+        job_unlock();
+        job->cb(job->opaque, job_ret);
+        job_lock();
     }
 
     /* Emit events only if we actually started */
     if (job_started(job)) {
-        if (job_is_cancelled(job)) {
+        if (job_is_cancelled_locked(job)) {
             job_event_cancelled(job);
         } else {
             job_event_completed(job);
@@ -832,7 +863,9 @@ static void job_cancel_async(Job *job, bool force)
 {
     assert(qemu_in_main_thread());
     if (job->driver->cancel) {
+        job_unlock();
         force = job->driver->cancel(job, force);
+        job_lock();
     } else {
         /* No .cancel() means the job will behave as if force-cancelled */
         force = true;
@@ -841,7 +874,9 @@ static void job_cancel_async(Job *job, bool force)
     if (job->user_paused) {
         /* Do not call job_enter here, the caller will handle it.  */
         if (job->driver->user_resume) {
+            job_unlock();
             job->driver->user_resume(job);
+            job_lock();
         }
         job->user_paused = false;
         assert(job->pause_count > 0);
@@ -911,7 +946,7 @@ static void job_completed_txn_abort(Job *job)
         ctx = other_job->aio_context;
         aio_context_acquire(ctx);
         if (!job_is_completed_locked(other_job)) {
-            assert(job_cancel_requested(other_job));
+            assert(job_cancel_requested_locked(other_job));
             job_finish_sync_locked(other_job, NULL, NULL);
         }
         job_finalize_single(other_job);
@@ -930,13 +965,17 @@ static void job_completed_txn_abort(Job *job)
 
 static int job_prepare(Job *job)
 {
+    int ret;
     AioContext *ctx = job->aio_context;
     assert(qemu_in_main_thread());
 
     if (job->ret == 0 && job->driver->prepare) {
+        job_unlock();
         aio_context_acquire(ctx);
-        job->ret = job->driver->prepare(job);
+        ret = job->driver->prepare(job);
         aio_context_release(ctx);
+        job_lock();
+        job->ret = ret;
         job_update_rc(job);
     }
 
@@ -982,6 +1021,7 @@ static int job_transition_to_pending(Job *job)
 
 void job_transition_to_ready(Job *job)
 {
+    JOB_LOCK_GUARD();
     job_state_transition(job, JOB_STATUS_READY);
     job_event_ready(job);
 }
@@ -1031,6 +1071,7 @@ static void job_exit(void *opaque)
     Job *job = (Job *)opaque;
     AioContext *ctx;
 
+    JOB_LOCK_GUARD();
     job_ref_locked(job);
     aio_context_acquire(job->aio_context);
 
@@ -1061,13 +1102,17 @@ static void job_exit(void *opaque)
 static void coroutine_fn job_co_entry(void *opaque)
 {
     Job *job = opaque;
+    int ret;
 
     assert(job->aio_context == qemu_get_current_aio_context());
     assert(job && job->driver && job->driver->run);
     job_pause_point(job);
-    job->ret = job->driver->run(job, &job->err);
-    job->deferred_to_main_loop = true;
-    job->busy = true;
+    ret = job->driver->run(job, &job->err);
+    WITH_JOB_LOCK_GUARD() {
+        job->ret = ret;
+        job->deferred_to_main_loop = true;
+        job->busy = true;
+    }
     aio_bh_schedule_oneshot(qemu_get_aio_context(), job_exit, job);
 }
 
@@ -1083,16 +1128,20 @@ static int job_pre_run(Job *job)
 
 void job_start(Job *job)
 {
-    assert(job && !job_started(job) && job->paused &&
-           job->driver && job->driver->run);
-    job->co = qemu_coroutine_create(job_co_entry, job);
+    WITH_JOB_LOCK_GUARD() {
+        assert(job && !job_started(job) && job->paused &&
+            job->driver && job->driver->run);
+        job->co = qemu_coroutine_create(job_co_entry, job);
+    }
     if (job_pre_run(job)) {
         return;
     }
-    job->pause_count--;
-    job->busy = true;
-    job->paused = false;
-    job_state_transition(job, JOB_STATUS_RUNNING);
+    WITH_JOB_LOCK_GUARD() {
+        job->pause_count--;
+        job->busy = true;
+        job->paused = false;
+        job_state_transition(job, JOB_STATUS_RUNNING);
+    }
     aio_co_enter(job->aio_context, job->co);
 }
 
@@ -1116,11 +1165,11 @@ void job_cancel_locked(Job *job, bool force)
          * choose to call job_is_cancelled() to show that we invoke
          * job_completed_txn_abort() only for force-cancelled jobs.)
          */
-        if (job_is_cancelled(job)) {
+        if (job_is_cancelled_locked(job)) {
             job_completed_txn_abort(job);
         }
     } else {
-        job_enter(job);
+        job_enter_cond_locked(job, NULL);
     }
 }
 
@@ -1164,6 +1213,7 @@ void job_cancel_sync_all(void)
     Job *job;
     AioContext *aio_context;
 
+    JOB_LOCK_GUARD();
     while ((job = job_next_locked(NULL))) {
         aio_context = job->aio_context;
         aio_context_acquire(aio_context);
@@ -1185,13 +1235,15 @@ void job_complete_locked(Job *job, Error **errp)
     if (job_apply_verb_locked(job, JOB_VERB_COMPLETE, errp)) {
         return;
     }
-    if (job_cancel_requested(job) || !job->driver->complete) {
+    if (job_cancel_requested_locked(job) || !job->driver->complete) {
         error_setg(errp, "The active block job '%s' cannot be completed",
                    job->id);
         return;
     }
 
+    job_unlock();
     job->driver->complete(job, errp);
+    job_lock();
 }
 
 int job_finish_sync_locked(Job *job, void (*finish)(Job *, Error **errp),
@@ -1211,10 +1263,12 @@ int job_finish_sync_locked(Job *job, void (*finish)(Job *, Error **errp),
         return -EBUSY;
     }
 
-    AIO_WAIT_WHILE(job->aio_context,
-                   (job_enter(job), !job_is_completed_locked(job)));
+    job_unlock();
+    AIO_WAIT_WHILE(job->aio_context, (job_enter(job), !job_is_completed(job)));
+    job_lock();
 
-    ret = (job_is_cancelled(job) && job->ret == 0) ? -ECANCELED : job->ret;
+    ret = (job_is_cancelled_locked(job) && job->ret == 0) ?
+           -ECANCELED : job->ret;
     job_unref_locked(job);
     return ret;
 }
diff --git a/monitor/qmp-cmds.c b/monitor/qmp-cmds.c
index 343353e27a..2f11d086a6 100644
--- a/monitor/qmp-cmds.c
+++ b/monitor/qmp-cmds.c
@@ -133,8 +133,10 @@ void qmp_cont(Error **errp)
         blk_iostatus_reset(blk);
     }
 
-    for (job = block_job_next(NULL); job; job = block_job_next(job)) {
-        block_job_iostatus_reset(job);
+    WITH_JOB_LOCK_GUARD() {
+        for (job = block_job_next(NULL); job; job = block_job_next(job)) {
+            block_job_iostatus_reset(job);
+        }
     }
 
     /* Continuing after completed migration. Images have been inactivated to
diff --git a/qemu-img.c b/qemu-img.c
index 09f3b11eab..95e2e33e61 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -906,25 +906,30 @@ static void run_block_job(BlockJob *job, Error **errp)
     int ret = 0;
 
     aio_context_acquire(aio_context);
-    job_ref_locked(&job->job);
-    do {
-        float progress = 0.0f;
-        aio_poll(aio_context, true);
+    WITH_JOB_LOCK_GUARD() {
+        job_ref_locked(&job->job);
+        do {
+            float progress = 0.0f;
+            job_unlock();
+            aio_poll(aio_context, true);
+
+            progress_get_snapshot(&job->job.progress, &progress_current,
+                                &progress_total);
+            if (progress_total) {
+                progress = (float)progress_current / progress_total * 100.f;
+            }
+            qemu_progress_print(progress, 0);
+            job_lock();
+        } while (!job_is_ready_locked(&job->job) &&
+                !job_is_completed_locked(&job->job));
 
-        progress_get_snapshot(&job->job.progress, &progress_current,
-                              &progress_total);
-        if (progress_total) {
-            progress = (float)progress_current / progress_total * 100.f;
+        if (!job_is_completed_locked(&job->job)) {
+            ret = job_complete_sync_locked(&job->job, errp);
+        } else {
+            ret = job->job.ret;
         }
-        qemu_progress_print(progress, 0);
-    } while (!job_is_ready(&job->job) && !job_is_completed_locked(&job->job));
-
-    if (!job_is_completed_locked(&job->job)) {
-        ret = job_complete_sync_locked(&job->job, errp);
-    } else {
-        ret = job->job.ret;
+        job_unref_locked(&job->job);
     }
-    job_unref_locked(&job->job);
     aio_context_release(aio_context);
 
     /* publish completion progress only when success */
@@ -1077,7 +1082,9 @@ static int img_commit(int argc, char **argv)
         bdrv_ref(bs);
     }
 
-    job = block_job_get("commit");
+    WITH_JOB_LOCK_GUARD() {
+        job = block_job_get("commit");
+    }
     assert(job);
     run_block_job(job, &local_err);
     if (local_err) {
-- 
2.31.1