[PATCH v4 3/5] qmp: expose block-dirty-bitmap-populate

[Eric Blake]

From: John Snow <jsnow@redhat.com>

This is a new job-creating command.

Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 qapi/block-core.json  | 18 +++++++++++
 qapi/transaction.json |  2 ++
 blockdev.c            | 74 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 94 insertions(+)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index 1cac9a9a8207..ed05c0bfa720 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -2264,6 +2264,24 @@
             '*auto-finalize': 'bool',
             '*auto-dismiss': 'bool' } }

+##
+# @block-dirty-bitmap-populate:
+#
+# Creates a new job that writes a pattern into a dirty bitmap.
+#
+# Since: 5.2
+#
+# Example:
+#
+# -> { "execute": "block-dirty-bitmap-populate",
+#      "arguments": { "node": "drive0", "target": "bitmap0",
+#                     "job-id": "job0", "pattern": "allocate-top" } }
+# <- { "return": {} }
+#
+##
+{ 'command': 'block-dirty-bitmap-populate', 'boxed': true,
+  'data': 'BlockDirtyBitmapPopulate' }
+
 ##
 # @BlockDirtyBitmapSha256:
 #
diff --git a/qapi/transaction.json b/qapi/transaction.json
index 15ddebdbc360..8302b824e4d5 100644
--- a/qapi/transaction.json
+++ b/qapi/transaction.json
@@ -51,6 +51,7 @@
 # - @block-dirty-bitmap-enable: since 4.0
 # - @block-dirty-bitmap-disable: since 4.0
 # - @block-dirty-bitmap-merge: since 4.0
+# - @block-dirty-bitmap-populate: since 5.2
 # - @blockdev-backup: since 2.3
 # - @blockdev-snapshot: since 2.5
 # - @blockdev-snapshot-internal-sync: since 1.7
@@ -68,6 +69,7 @@
        'block-dirty-bitmap-enable': 'BlockDirtyBitmap',
        'block-dirty-bitmap-disable': 'BlockDirtyBitmap',
        'block-dirty-bitmap-merge': 'BlockDirtyBitmapMerge',
+       'block-dirty-bitmap-populate': 'BlockDirtyBitmapPopulate',
        'blockdev-backup': 'BlockdevBackup',
        'blockdev-snapshot': 'BlockdevSnapshot',
        'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal',
diff --git a/blockdev.c b/blockdev.c
index f177048a4fe8..3657377d2aca 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2190,6 +2190,63 @@ static void 
block_dirty_bitmap_remove_commit(BlkActionState *common)
     bdrv_release_dirty_bitmap(state->bitmap);
 }

+static void block_dirty_bitmap_populate_prepare(BlkActionState *common,
+                                                Error **errp)
+{
+    BlockJobActionState *state = DO_UPCAST(BlockJobActionState, common, 
common);
+    BlockDirtyBitmapPopulate *bitpop;
+    BlockDriverState *bs;
+    AioContext *aio_context;
+    BdrvDirtyBitmap *bmap = NULL;
+    int job_flags = JOB_DEFAULT;
+
+    assert(common->action->type ==
+           TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_POPULATE);
+    bitpop = common->action->u.block_dirty_bitmap_populate.data;
+
+    bmap = block_dirty_bitmap_lookup(bitpop->node, bitpop->name, &bs, errp);
+    if (!bmap) {
+        return;
+    }
+
+    aio_context = bdrv_get_aio_context(bs);
+    aio_context_acquire(aio_context);
+    state->bs = bs;
+
+    /* Paired with .clean() */
+    bdrv_drained_begin(state->bs);
+
+    if (!bitpop->has_on_error) {
+        bitpop->on_error = BLOCKDEV_ON_ERROR_REPORT;
+    }
+    if (!bitpop->has_auto_finalize) {
+        bitpop->auto_finalize = true;
+    }
+    if (!bitpop->has_auto_dismiss) {
+        bitpop->auto_dismiss = true;
+    }
+
+    if (!bitpop->auto_finalize) {
+        job_flags |= JOB_MANUAL_FINALIZE;
+    }
+    if (!bitpop->auto_dismiss) {
+        job_flags |= JOB_MANUAL_DISMISS;
+    }
+
+    state->job = bitpop_job_create(
+        bitpop->job_id,
+        bs,
+        bmap,
+        bitpop->pattern,
+        bitpop->on_error,
+        job_flags,
+        NULL, NULL,
+        common->block_job_txn,
+        errp);
+
+    aio_context_release(aio_context);
+}
+
 static void abort_prepare(BlkActionState *common, Error **errp)
 {
     error_setg(errp, "Transaction aborted using Abort action");
@@ -2273,6 +2330,13 @@ static const BlkActionOps actions[] = {
         .commit = block_dirty_bitmap_remove_commit,
         .abort = block_dirty_bitmap_remove_abort,
     },
+    [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_POPULATE] = {
+        .instance_size = sizeof(BlockJobActionState),
+        .prepare = block_dirty_bitmap_populate_prepare,
+        .commit = blockdev_backup_commit,
+        .abort = blockdev_backup_abort,
+        .clean = blockdev_backup_clean,
+    },
     /* Where are transactions for MIRROR, COMMIT and STREAM?
      * Although these blockjobs use transaction callbacks like the backup job,
      * these jobs do not necessarily adhere to transaction semantics.
@@ -2392,6 +2456,16 @@ void qmp_block_passwd(bool has_device, const char 
*device,
                "Setting block passwords directly is no longer supported");
 }

+void qmp_block_dirty_bitmap_populate(BlockDirtyBitmapPopulate *bitpop,
+                                     Error **errp)
+{
+    TransactionAction action = {
+        .type = TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_POPULATE,
+        .u.block_dirty_bitmap_populate.data = bitpop,
+    };
+    blockdev_do_action(&action, errp);
+}
+
 BlockDirtyBitmapSha256 *qmp_x_debug_block_dirty_bitmap_sha256(const char *node,
                                                               const char *name,
                                                               Error **errp)
-- 
2.28.0