job: Add error message for failing jobs

So far we relied on job->ret and strerror() to produce an error message
for failed jobs. Not surprisingly, this tends to result in completely
useless messages.

This adds a Job.error field that can contain an error string for a
failing job, and a parameter to job_completed() that sets the field. As
a default, if NULL is passed, we continue to use strerror(job->ret).

All existing callers are changed to pass NULL. They can be improved in
separate patches.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>

3 files changed, 3 insertions, 3 deletions

diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
index 2cba63b881..a11c4cfbf2 100644
--- a/tests/test-bdrv-drain.c
+++ b/tests/test-bdrv-drain.c
@@ -498,7 +498,7 @@ typedef struct TestBlockJob {
 
 static void test_job_completed(Job *job, void *opaque)
 {
-    job_completed(job, 0);
+    job_completed(job, 0, NULL);
 }
 
 static void coroutine_fn test_job_start(void *opaque)
diff --git a/tests/test-blockjob-txn.c b/tests/test-blockjob-txn.c
index fce836639a..58d9b87fb2 100644
--- a/tests/test-blockjob-txn.c
+++ b/tests/test-blockjob-txn.c
@@ -34,7 +34,7 @@ static void test_block_job_complete(Job *job, void *opaque)
         rc = -ECANCELED;
     }
 
-    job_completed(job, rc);
+    job_completed(job, rc, NULL);
     bdrv_unref(bs);
 }
 
diff --git a/tests/test-blockjob.c b/tests/test-blockjob.c
index e408d52351..cb42f06e61 100644
--- a/tests/test-blockjob.c
+++ b/tests/test-blockjob.c
@@ -167,7 +167,7 @@ static void cancel_job_completed(Job *job, void *opaque)
 {
     CancelJob *s = opaque;
     s->completed = true;
-    job_completed(job, 0);
+    job_completed(job, 0, NULL);
 }
 
 static void cancel_job_complete(Job *job, Error **errp)