We want to simplify initialization interface of copy-before-write
filter as we are going to make it public. So, let's detect fleecing
scheme exactly in block-copy code, to not pass this information through
extra levels.
Why not just set BDRV_REQ_SERIALISING unconditionally: because we are
going to implement new more efficient fleecing scheme which will not
rely on backing feature.
Signed-off-by: Vladimir Sementsov-Ogievskiy
---
block/copy-before-write.h | 2 +-
include/block/block-copy.h | 3 +--
block/backup.c | 21 +
block/block-copy.c | 24 +---
block/copy-before-write.c | 4 ++--
5 files changed, 26 insertions(+), 28 deletions(-)
diff --git a/block/copy-before-write.h b/block/copy-before-write.h
index 5977b7aa31..f37e2249ae 100644
--- a/block/copy-before-write.h
+++ b/block/copy-before-write.h
@@ -34,7 +34,7 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
const char *filter_node_name,
uint64_t cluster_size,
BackupPerf *perf,
- BdrvRequestFlags write_flags,
+ bool compress,
BlockCopyState **bcs,
Error **errp);
void bdrv_cbw_drop(BlockDriverState *bs);
diff --git a/include/block/block-copy.h b/include/block/block-copy.h
index 5c8278895c..734389d32a 100644
--- a/include/block/block-copy.h
+++ b/include/block/block-copy.h
@@ -26,8 +26,7 @@ typedef struct BlockCopyCallState BlockCopyCallState;
BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild *target,
int64_t cluster_size, bool use_copy_range,
- BdrvRequestFlags write_flags,
- Error **errp);
+ bool compress, Error **errp);
void block_copy_set_progress_meter(BlockCopyState *s, ProgressMeter *pm);
diff --git a/block/backup.c b/block/backup.c
index ac91821b08..84f9a5f02c 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -407,7 +407,6 @@ BlockJob *backup_job_create(const char *job_id,
BlockDriverState *bs,
int64_t len, target_len;
BackupBlockJob *job = NULL;
int64_t cluster_size;
-BdrvRequestFlags write_flags;
BlockDriverState *cbw = NULL;
BlockCopyState *bcs = NULL;
@@ -504,26 +503,8 @@ BlockJob *backup_job_create(const char *job_id,
BlockDriverState *bs,
goto error;
}
-/*
- * If source is in backing chain of target assume that target is going to
be
- * used for "image fleecing", i.e. it should represent a kind of snapshot
of
- * source at backup-start point in time. And target is going to be read by
- * somebody (for example, used as NBD export) during backup job.
- *
- * In this case, we need to add BDRV_REQ_SERIALISING write flag to avoid
- * intersection of backup writes and third party reads from target,
- * otherwise reading from target we may occasionally read already updated
by
- * guest data.
- *
- * For more information see commit f8d59dfb40bb and test
- * tests/qemu-iotests/222
- */
-write_flags = (bdrv_chain_contains(target, bs) ? BDRV_REQ_SERIALISING : 0)
|
- (compress ? BDRV_REQ_WRITE_COMPRESSED : 0),
-
cbw = bdrv_cbw_append(bs, target, filter_node_name,
-cluster_size, perf,
-write_flags, , errp);
+ cluster_size, perf, compress, , errp);
if (!cbw) {
goto error;
}
diff --git a/block/block-copy.c b/block/block-copy.c
index 0becad52da..58b4345a5a 100644
--- a/block/block-copy.c
+++ b/block/block-copy.c
@@ -317,10 +317,11 @@ static uint32_t block_copy_max_transfer(BdrvChild
*source, BdrvChild *target)
BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild *target,
int64_t cluster_size, bool use_copy_range,
- BdrvRequestFlags write_flags, Error
**errp)
+ bool compress, Error **errp)
{
BlockCopyState *s;
BdrvDirtyBitmap *copy_bitmap;
+bool is_fleecing;
copy_bitmap = bdrv_create_dirty_bitmap(source->bs, cluster_size, NULL,
errp);
@@ -329,6 +330,22 @@ BlockCopyState *block_copy_state_new(BdrvChild *source,
BdrvChild *target,
}
bdrv_disable_dirty_bitmap(copy_bitmap);
+/*
+ * If source is in backing chain of target assume that target is going to
be
+ * used for "image fleecing", i.e. it should represent a kind of snapshot
of
+ * source at backup-start point in time. And target is going to be read by
+ * somebody (for example, used as NBD export) during backup job.
+ *
+ * In this
