[Qemu-devel] [PATCH v2 15/16] block/mirror: Add copy mode QAPI interface

[Max Reitz <mreitz@redhat.com>]

This patch allows the user to specify whether to use active or only
passive mode for mirror block jobs.  Currently, this setting will remain
constant for the duration of the entire block job.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 qapi/block-core.json      | 11 +++++++++--
 include/block/block_int.h |  4 +++-
 block/mirror.c            | 12 +++++++-----
 blockdev.c                |  9 ++++++++-
 4 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index ba1fd736f5..5fafa5fcac 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1573,6 +1573,9 @@
 #         written. Both will result in identical contents.
 #         Default is true. (Since 2.4)
 #
+# @copy-mode: when to copy data to the destination; defaults to 'passive'
+#             (Since: 2.12)
+#
 # Since: 1.3
 ##
 { 'struct': 'DriveMirror',
@@ -1582,7 +1585,7 @@
             '*speed': 'int', '*granularity': 'uint32',
             '*buf-size': 'int', '*on-source-error': 'BlockdevOnError',
             '*on-target-error': 'BlockdevOnError',
-            '*unmap': 'bool' } }
+            '*unmap': 'bool', '*copy-mode': 'MirrorCopyMode' } }
 
 ##
 # @BlockDirtyBitmap:
@@ -1761,6 +1764,9 @@
 #                    above @device. If this option is not given, a node name is
 #                    autogenerated. (Since: 2.9)
 #
+# @copy-mode: when to copy data to the destination; defaults to 'passive'
+#             (Since: 2.12)
+#
 # Returns: nothing on success.
 #
 # Since: 2.6
@@ -1781,7 +1787,8 @@
             '*speed': 'int', '*granularity': 'uint32',
             '*buf-size': 'int', '*on-source-error': 'BlockdevOnError',
             '*on-target-error': 'BlockdevOnError',
-            '*filter-node-name': 'str' } }
+            '*filter-node-name': 'str',
+            '*copy-mode': 'MirrorCopyMode' } }
 
 ##
 # @block_set_io_throttle:
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 03f3fdd129..1fda4d3d43 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -948,6 +948,7 @@ void commit_active_start(const char *job_id, BlockDriverState *bs,
  * @filter_node_name: The node name that should be assigned to the filter
  * driver that the mirror job inserts into the graph above @bs. NULL means that
  * a node name should be autogenerated.
+ * @copy_mode: When to trigger writes to the target.
  * @errp: Error object.
  *
  * Start a mirroring operation on @bs.  Clusters that are allocated
@@ -961,7 +962,8 @@ void mirror_start(const char *job_id, BlockDriverState *bs,
                   MirrorSyncMode mode, BlockMirrorBackingMode backing_mode,
                   BlockdevOnError on_source_error,
                   BlockdevOnError on_target_error,
-                  bool unmap, const char *filter_node_name, Error **errp);
+                  bool unmap, const char *filter_node_name,
+                  MirrorCopyMode copy_mode, Error **errp);
 
 /*
  * backup_job_create:
diff --git a/block/mirror.c b/block/mirror.c
index 83082adb64..3b23886a5a 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1409,7 +1409,7 @@ static void mirror_start_job(const char *job_id, BlockDriverState *bs,
                              const BlockJobDriver *driver,
                              bool is_none_mode, BlockDriverState *base,
                              bool auto_complete, const char *filter_node_name,
-                             bool is_mirror,
+                             bool is_mirror, MirrorCopyMode copy_mode,
                              Error **errp)
 {
     MirrorBlockJob *s;
@@ -1515,7 +1515,7 @@ static void mirror_start_job(const char *job_id, BlockDriverState *bs,
     s->on_target_error = on_target_error;
     s->is_none_mode = is_none_mode;
     s->backing_mode = backing_mode;
-    s->copy_mode = MIRROR_COPY_MODE_BACKGROUND;
+    s->copy_mode = copy_mode;
     s->base = base;
     s->granularity = granularity;
     s->buf_size = ROUND_UP(buf_size, granularity);
@@ -1582,7 +1582,8 @@ void mirror_start(const char *job_id, BlockDriverState *bs,
                   MirrorSyncMode mode, BlockMirrorBackingMode backing_mode,
                   BlockdevOnError on_source_error,
                   BlockdevOnError on_target_error,
-                  bool unmap, const char *filter_node_name, Error **errp)
+                  bool unmap, const char *filter_node_name,
+                  MirrorCopyMode copy_mode, Error **errp)
 {
     bool is_none_mode;
     BlockDriverState *base;
@@ -1597,7 +1598,7 @@ void mirror_start(const char *job_id, BlockDriverState *bs,
                      speed, granularity, buf_size, backing_mode,
                      on_source_error, on_target_error, unmap, NULL, NULL,
                      &mirror_job_driver, is_none_mode, base, false,
-                     filter_node_name, true, errp);
+                     filter_node_name, true, copy_mode, errp);
 }
 
 void commit_active_start(const char *job_id, BlockDriverState *bs,
@@ -1620,7 +1621,8 @@ void commit_active_start(const char *job_id, BlockDriverState *bs,
                      MIRROR_LEAVE_BACKING_CHAIN,
                      on_error, on_error, true, cb, opaque,
                      &commit_active_job_driver, false, base, auto_complete,
-                     filter_node_name, false, &local_err);
+                     filter_node_name, false, MIRROR_COPY_MODE_BACKGROUND,
+                     &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         goto error_restore_flags;
diff --git a/blockdev.c b/blockdev.c
index 8e977eef11..35d8228819 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3491,6 +3491,7 @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
                                    bool has_unmap, bool unmap,
                                    bool has_filter_node_name,
                                    const char *filter_node_name,
+                                   bool has_copy_mode, MirrorCopyMode copy_mode,
                                    Error **errp)
 {
 
@@ -3515,6 +3516,9 @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
     if (!has_filter_node_name) {
         filter_node_name = NULL;
     }
+    if (!has_copy_mode) {
+        copy_mode = MIRROR_COPY_MODE_BACKGROUND;
+    }
 
     if (granularity != 0 && (granularity < 512 || granularity > 1048576 * 64)) {
         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "granularity",
@@ -3545,7 +3549,7 @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
                  has_replaces ? replaces : NULL,
                  speed, granularity, buf_size, sync, backing_mode,
                  on_source_error, on_target_error, unmap, filter_node_name,
-                 errp);
+                 copy_mode, errp);
 }
 
 void qmp_drive_mirror(DriveMirror *arg, Error **errp)
@@ -3686,6 +3690,7 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp)
                            arg->has_on_target_error, arg->on_target_error,
                            arg->has_unmap, arg->unmap,
                            false, NULL,
+                           arg->has_copy_mode, arg->copy_mode,
                            &local_err);
     bdrv_unref(target_bs);
     error_propagate(errp, local_err);
@@ -3706,6 +3711,7 @@ void qmp_blockdev_mirror(bool has_job_id, const char *job_id,
                          BlockdevOnError on_target_error,
                          bool has_filter_node_name,
                          const char *filter_node_name,
+                         bool has_copy_mode, MirrorCopyMode copy_mode,
                          Error **errp)
 {
     BlockDriverState *bs;
@@ -3738,6 +3744,7 @@ void qmp_blockdev_mirror(bool has_job_id, const char *job_id,
                            has_on_target_error, on_target_error,
                            true, true,
                            has_filter_node_name, filter_node_name,
+                           has_copy_mode, copy_mode,
                            &local_err);
     error_propagate(errp, local_err);
 
-- 
2.14.3