block/copy-before-write: initialize block-copy bitmap

We are going to publish copy-before-write filter to be used in separate
of backup. Future step would support bitmap for the filter. But let's
start from full set bitmap.

We have to modify backup, as bitmap is first initialized by
copy-before-write filter, and then backup modifies it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210824083856.17408-20-vsementsov@virtuozzo.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>

diff --git a/block/backup.c b/block/backup.c
index 4869f1e5dadeb0b44a44d91f034b225e66568084..687d2882bcbb1a40d45cd0e0dadc73637a3c942b 100644 (file)
--- a/block/backup.c
+++ b/block/backup.c
@@ -233,18 +233,16 @@ static void backup_init_bcs_bitmap(BackupBlockJob *job)
     BdrvDirtyBitmap *bcs_bitmap = block_copy_dirty_bitmap(job->bcs);
 
     if (job->sync_mode == MIRROR_SYNC_MODE_BITMAP) {
+        bdrv_clear_dirty_bitmap(bcs_bitmap, NULL);
         ret = bdrv_dirty_bitmap_merge_internal(bcs_bitmap, job->sync_bitmap,
                                                NULL, true);
         assert(ret);
-    } else {
-        if (job->sync_mode == MIRROR_SYNC_MODE_TOP) {
-            /*
-             * We can't hog the coroutine to initialize this thoroughly.
-             * Set a flag and resume work when we are able to yield safely.
-             */
-            block_copy_set_skip_unallocated(job->bcs, true);
-        }
-        bdrv_set_dirty_bitmap(bcs_bitmap, 0, job->len);
+    } else if (job->sync_mode == MIRROR_SYNC_MODE_TOP) {
+        /*
+         * We can't hog the coroutine to initialize this thoroughly.
+         * Set a flag and resume work when we are able to yield safely.
+         */
+        block_copy_set_skip_unallocated(job->bcs, true);
     }
 
     estimate = bdrv_get_dirty_count(bcs_bitmap);

diff --git a/block/copy-before-write.c b/block/copy-before-write.c
index 1cefcade7871ff7aa478cbbe460d9bc73b0f669b..2efe098aae15d76b0e97750e8e23a25495ec1199 100644 (file)
--- a/block/copy-before-write.c
+++ b/block/copy-before-write.c
@@ -147,6 +147,7 @@ static void cbw_child_perm(BlockDriverState *bs, BdrvChild *c,
 static int cbw_init(BlockDriverState *bs, QDict *options, Error **errp)
 {
     BDRVCopyBeforeWriteState *s = bs->opaque;
+    BdrvDirtyBitmap *copy_bitmap;
 
     bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
                                BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
@@ -174,6 +175,9 @@ static int cbw_init(BlockDriverState *bs, QDict *options, Error **errp)
         return -EINVAL;
     }
 
+    copy_bitmap = block_copy_dirty_bitmap(s->bcs);
+    bdrv_set_dirty_bitmap(copy_bitmap, 0, bdrv_dirty_bitmap_size(copy_bitmap));
+
     return 0;
 }