stream: Add 'job-id' parameter to 'block-stream'

This patch adds a new optional 'job-id' parameter to 'block-stream',
allowing the user to specify the ID of the block job to be created.

The HMP 'block_stream' command remains unchanged.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block/stream.c

@@ -218,15 +218,15 @@ static const BlockJobDriver stream_job_driver = {
     .set_speed     = stream_set_speed,
 };
 
-void stream_start(BlockDriverState *bs, BlockDriverState *base,
-                  const char *backing_file_str, int64_t speed,
-                  BlockdevOnError on_error,
-                  BlockCompletionFunc *cb,
-                  void *opaque, Error **errp)
+void stream_start(const char *job_id, BlockDriverState *bs,
+                  BlockDriverState *base, const char *backing_file_str,
+                  int64_t speed, BlockdevOnError on_error,
+                  BlockCompletionFunc *cb, void *opaque, Error **errp)
 {
     StreamBlockJob *s;
 
-    s = block_job_create(NULL, &stream_job_driver, bs, speed, cb, opaque, errp);
+    s = block_job_create(job_id, &stream_job_driver, bs, speed,
+                         cb, opaque, errp);
     if (!s) {
         return;
     }

blockdev.c

@@ -3005,7 +3005,7 @@ static void block_job_cb(void *opaque, int ret)
     }
 }
 
-void qmp_block_stream(const char *device,
+void qmp_block_stream(bool has_job_id, const char *job_id, const char *device,
                       bool has_base, const char *base,
                       bool has_backing_file, const char *backing_file,
                       bool has_speed, int64_t speed,
@@ -3064,8 +3064,8 @@ void qmp_block_stream(const char *device,
     /* backing_file string overrides base bs filename */
     base_name = has_backing_file ? backing_file : base_name;
 
-    stream_start(bs, base_bs, base_name, has_speed ? speed : 0,
-                 on_error, block_job_cb, bs, &local_err);
+    stream_start(has_job_id ? job_id : NULL, bs, base_bs, base_name,
+                 has_speed ? speed : 0, on_error, block_job_cb, bs, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         goto out;

hmp.c

@@ -1485,7 +1485,7 @@ void hmp_block_stream(Monitor *mon, const QDict *qdict)
     const char *base = qdict_get_try_str(qdict, "base");
     int64_t speed = qdict_get_try_int(qdict, "speed", 0);
 
-    qmp_block_stream(device, base != NULL, base, false, NULL,
+    qmp_block_stream(false, NULL, device, base != NULL, base, false, NULL,
                      qdict_haskey(qdict, "speed"), speed,
                      true, BLOCKDEV_ON_ERROR_REPORT, &error);
 

include/block/block_int.h

@@ -639,6 +639,8 @@ int is_windows_drive(const char *filename);
 
 /**
  * stream_start:
+ * @job_id: The id of the newly-created job, or %NULL to use the
+ * device name of @bs.
  * @bs: Block device to operate on.
  * @base: Block device that will become the new base, or %NULL to
  * flatten the whole backing file chain onto @bs.
@@ -657,10 +659,10 @@ int is_windows_drive(const char *filename);
  * @backing_file_str in the written image and to @base in the live
  * BlockDriverState.
  */
-void stream_start(BlockDriverState *bs, BlockDriverState *base,
-                  const char *backing_file_str, int64_t speed,
-                  BlockdevOnError on_error, BlockCompletionFunc *cb,
-                  void *opaque, Error **errp);
+void stream_start(const char *job_id, BlockDriverState *bs,
+                  BlockDriverState *base, const char *backing_file_str,
+                  int64_t speed, BlockdevOnError on_error,
+                  BlockCompletionFunc *cb, void *opaque, Error **errp);
 
 /**
  * commit_start:

qapi/block-core.json

@@ -1425,6 +1425,9 @@
 # On successful completion the image file is updated to drop the backing file
 # and the BLOCK_JOB_COMPLETED event is emitted.
 #
+# @job-id: #optional identifier for the newly-created block job. If
+#          omitted, the device name will be used. (Since 2.7)
+#
 # @device: the device name
 #
 # @base:   #optional the common backing file name
@@ -1456,8 +1459,9 @@
 # Since: 1.1
 ##
 { 'command': 'block-stream',
-  'data': { 'device': 'str', '*base': 'str', '*backing-file': 'str',
-            '*speed': 'int', '*on-error': 'BlockdevOnError' } }
+  'data': { '*job-id': 'str', 'device': 'str', '*base': 'str',
+            '*backing-file': 'str', '*speed': 'int',
+            '*on-error': 'BlockdevOnError' } }
 
 ##
 # @block-job-set-speed:

qmp-commands.hx

@@ -1106,7 +1106,7 @@ EQMP
 
     {
         .name       = "block-stream",
-        .args_type  = "device:B,base:s?,speed:o?,backing-file:s?,on-error:s?",
+        .args_type  = "job-id:s?,device:B,base:s?,speed:o?,backing-file:s?,on-error:s?",
         .mhandler.cmd_new = qmp_marshal_block_stream,
     },
 
@@ -1118,6 +1118,8 @@ Copy data from a backing file into a block device.
 
 Arguments:
 
+- "job-id": Identifier for the newly-created block job. If omitted,
+            the device name will be used. (json-string, optional)
 - "device": The device's ID, must be unique (json-string)
 - "base": The file name of the backing image above which copying starts
           (json-string, optional)