From: Max Reitz <mre...@redhat.com>
The commit and mirror block nodes are filters, so they should be marked
as such.
Signed-off-by: Max Reitz <mre...@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
[squash comment fix from another Max's patch and adjust commit msg]
---
include/block/block_int.h | 8 +++++---
block/commit.c | 2 ++
block/mirror.c | 2 ++
3 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 0422acdf1c..4af0fa8fe4 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -89,9 +89,11 @@ struct BlockDriver {
int instance_size;
/* set to true if the BlockDriver is a block filter. Block filters pass
- * certain callbacks that refer to data (see block.c) to their bs->file if
- * the driver doesn't implement them. Drivers that do not wish to forward
- * must implement them and return -ENOTSUP.
+ * certain callbacks that refer to data (see block.c) to their bs->file
+ * or bs->backing (whichever one exists) if the driver doesn't implement
+ * them. Drivers that do not wish to forward must implement them and return
+ * -ENOTSUP.
+ * Note that filters are not allowed to modify data.
*/
bool is_filter;
/* for snapshots block filter like Quorum can implement the
diff --git a/block/commit.c b/block/commit.c
index bc8454463d..07e7a3cd0a 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -253,6 +253,8 @@ static BlockDriver bdrv_commit_top = {
.bdrv_co_block_status = bdrv_co_block_status_from_backing,
.bdrv_refresh_filename = bdrv_commit_top_refresh_filename,
.bdrv_child_perm = bdrv_commit_top_child_perm,
+
+ .is_filter = true,
};
void commit_start(const char *job_id, BlockDriverState *bs,
diff --git a/block/mirror.c b/block/mirror.c
index fe984efb90..838781dfaa 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1487,6 +1487,8 @@ static BlockDriver bdrv_mirror_top = {
.bdrv_refresh_filename = bdrv_mirror_top_refresh_filename,
.bdrv_child_perm = bdrv_mirror_top_child_perm,
.bdrv_refresh_limits = bdrv_mirror_top_refresh_limits,
+
+ .is_filter = true,
};
static BlockJob *mirror_start_job(
--
2.21.0
