From 345f9e1b04ee18dcb1454dcec49781d5e06ecb60 Mon Sep 17 00:00:00 2001
From: Max Reitz <mreitz@redhat.com>
Date: Fri, 24 Oct 2014 15:57:33 +0200
Subject: [PATCH] blockjob: Introduce block_job_complete_sync()

Implement block_job_complete_sync() by doing the exact same thing as
block_job_cancel_sync() does, only with calling block_job_complete()
instead of block_job_cancel().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1414159063-25977-5-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 blockjob.c               | 39 ++++++++++++++++++++++++++++++++-------
 include/block/blockjob.h | 15 +++++++++++++++
 2 files changed, 47 insertions(+), 7 deletions(-)

diff --git a/blockjob.c b/blockjob.c
index ff0908a653..a7d57e3d33 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -153,7 +153,7 @@ void block_job_iostatus_reset(BlockJob *job)
     }
 }
 
-struct BlockCancelData {
+struct BlockFinishData {
     BlockJob *job;
     BlockCompletionFunc *cb;
     void *opaque;
@@ -161,19 +161,22 @@ struct BlockCancelData {
     int ret;
 };
 
-static void block_job_cancel_cb(void *opaque, int ret)
+static void block_job_finish_cb(void *opaque, int ret)
 {
-    struct BlockCancelData *data = opaque;
+    struct BlockFinishData *data = opaque;
 
     data->cancelled = block_job_is_cancelled(data->job);
     data->ret = ret;
     data->cb(data->opaque, ret);
 }
 
-int block_job_cancel_sync(BlockJob *job)
+static int block_job_finish_sync(BlockJob *job,
+                                 void (*finish)(BlockJob *, Error **errp),
+                                 Error **errp)
 {
-    struct BlockCancelData data;
+    struct BlockFinishData data;
     BlockDriverState *bs = job->bs;
+    Error *local_err = NULL;
 
     assert(bs->job == job);
 
@@ -184,15 +187,37 @@ int block_job_cancel_sync(BlockJob *job)
     data.cb = job->cb;
     data.opaque = job->opaque;
     data.ret = -EINPROGRESS;
-    job->cb = block_job_cancel_cb;
+    job->cb = block_job_finish_cb;
     job->opaque = &data;
-    block_job_cancel(job);
+    finish(job, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return -EBUSY;
+    }
     while (data.ret == -EINPROGRESS) {
         aio_poll(bdrv_get_aio_context(bs), true);
     }
     return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
 }
 
+/* A wrapper around block_job_cancel() taking an Error ** parameter so it may be
+ * used with block_job_finish_sync() without the need for (rather nasty)
+ * function pointer casts there. */
+static void block_job_cancel_err(BlockJob *job, Error **errp)
+{
+    block_job_cancel(job);
+}
+
+int block_job_cancel_sync(BlockJob *job)
+{
+    return block_job_finish_sync(job, &block_job_cancel_err, NULL);
+}
+
+int block_job_complete_sync(BlockJob *job, Error **errp)
+{
+    return block_job_finish_sync(job, &block_job_complete, errp);
+}
+
 void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns)
 {
     assert(job->busy);
diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index acb399f87d..ab11a0f622 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -272,6 +272,21 @@ bool block_job_is_paused(BlockJob *job);
  */
 int block_job_cancel_sync(BlockJob *job);
 
+/**
+ * block_job_complete_sync:
+ * @job: The job to be completed.
+ * @errp: Error object which may be set by block_job_complete(); this is not
+ *        necessarily set on every error, the job return value has to be
+ *        checked as well.
+ *
+ * Synchronously complete the job.  The completion callback is called before the
+ * function returns, unless it is NULL (which is permissible when using this
+ * function).
+ *
+ * Returns the return value from the job.
+ */
+int block_job_complete_sync(BlockJob *job, Error **errp);
+
 /**
  * block_job_iostatus_reset:
  * @job: The job whose I/O status should be reset.