blockjobs: Allow creating internal jobs

Add the ability to create jobs without an ID.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 1477584421-1399-3-git-send-email-jsnow@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>

Author: jnsnow

block/backup.c

@@ -612,7 +612,7 @@ void backup_start(const char *job_id, BlockDriverState *bs,
     }
 
     job = block_job_create(job_id, &backup_job_driver, bs, speed,
-                           cb, opaque, errp);
+                           BLOCK_JOB_DEFAULT, cb, opaque, errp);
     if (!job) {
         goto error;
     }

block/commit.c

@@ -234,7 +234,7 @@ void commit_start(const char *job_id, BlockDriverState *bs,
     }
 
     s = block_job_create(job_id, &commit_job_driver, bs, speed,
-                         cb, opaque, errp);
+                         BLOCK_JOB_DEFAULT, cb, opaque, errp);
     if (!s) {
         return;
     }

block/mirror.c

@@ -967,7 +967,8 @@ static void mirror_start_job(const char *job_id, BlockDriverState *bs,
         buf_size = DEFAULT_MIRROR_BUF_SIZE;
     }
 
-    s = block_job_create(job_id, driver, bs, speed, cb, opaque, errp);
+    s = block_job_create(job_id, driver, bs, speed,
+                         BLOCK_JOB_DEFAULT, cb, opaque, errp);
     if (!s) {
         return;
     }

block/stream.c

@@ -230,7 +230,7 @@ void stream_start(const char *job_id, BlockDriverState *bs,
     int orig_bs_flags;
 
     s = block_job_create(job_id, &stream_job_driver, bs, speed,
-                         cb, opaque, errp);
+                         BLOCK_JOB_DEFAULT, cb, opaque, errp);
     if (!s) {
         return;
     }

blockjob.c

@@ -121,7 +121,7 @@ void block_job_add_bdrv(BlockJob *job, BlockDriverState *bs)
 }
 
 void *block_job_create(const char *job_id, const BlockJobDriver *driver,
-                       BlockDriverState *bs, int64_t speed,
+                       BlockDriverState *bs, int64_t speed, int flags,
                        BlockCompletionFunc *cb, void *opaque, Error **errp)
 {
     BlockBackend *blk;
@@ -133,22 +133,29 @@ void *block_job_create(const char *job_id, const BlockJobDriver *driver,
         return NULL;
     }
 
-    if (job_id == NULL) {
+    if (job_id == NULL && !(flags & BLOCK_JOB_INTERNAL)) {
         job_id = bdrv_get_device_name(bs);
         if (!*job_id) {
             error_setg(errp, "An explicit job ID is required for this node");
             return NULL;
         }
     }
 
-    if (!id_wellformed(job_id)) {
-        error_setg(errp, "Invalid job ID '%s'", job_id);
-        return NULL;
-    }
+    if (job_id) {
+        if (flags & BLOCK_JOB_INTERNAL) {
+            error_setg(errp, "Cannot specify job ID for internal block job");
+            return NULL;
+        }
 
-    if (block_job_get(job_id)) {
-        error_setg(errp, "Job ID '%s' already in use", job_id);
-        return NULL;
+        if (!id_wellformed(job_id)) {
+            error_setg(errp, "Invalid job ID '%s'", job_id);
+            return NULL;
+        }
+
+        if (block_job_get(job_id)) {
+            error_setg(errp, "Job ID '%s' already in use", job_id);
+            return NULL;
+        }
     }
 
     blk = blk_new();

include/block/blockjob.h

@@ -210,6 +210,11 @@ struct BlockJob {
     QLIST_ENTRY(BlockJob) txn_list;
 };
 
+typedef enum BlockJobCreateFlags {
+    BLOCK_JOB_DEFAULT = 0x00,
+    BLOCK_JOB_INTERNAL = 0x01,
+} BlockJobCreateFlags;
+
 /**
  * block_job_next:
  * @job: A block job, or %NULL.
@@ -252,7 +257,7 @@ BlockJob *block_job_get(const char *id);
  * called from a wrapper that is specific to the job type.
  */
 void *block_job_create(const char *job_id, const BlockJobDriver *driver,
-                       BlockDriverState *bs, int64_t speed,
+                       BlockDriverState *bs, int64_t speed, int flags,
                        BlockCompletionFunc *cb, void *opaque, Error **errp);
 
 /**

tests/test-blockjob-txn.c

@@ -98,7 +98,8 @@ static BlockJob *test_block_job_start(unsigned int iterations,
     bs = bdrv_new();
     snprintf(job_id, sizeof(job_id), "job%u", counter++);
     s = block_job_create(job_id, &test_block_job_driver, bs, 0,
-                         test_block_job_cb, data, &error_abort);
+                         BLOCK_JOB_DEFAULT, test_block_job_cb,
+                         data, &error_abort);
     s->iterations = iterations;
     s->use_timer = use_timer;
     s->rc = rc;

tests/test-blockjob.c

@@ -31,7 +31,7 @@ static BlockJob *do_test_id(BlockBackend *blk, const char *id,
     Error *errp = NULL;
 
     job = block_job_create(id, &test_block_job_driver, blk_bs(blk), 0,
-                           block_job_cb, NULL, &errp);
+                           BLOCK_JOB_DEFAULT, block_job_cb, NULL, &errp);
     if (should_succeed) {
         g_assert_null(errp);
         g_assert_nonnull(job);