From: Fam Zheng <f...@redhat.com>
This semantics is needed by drive-backup so implement it before using
this API there.
Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
Signed-off-by: Fam Zheng <f...@redhat.com>
Message-id: 20180703023758.14422-3-f...@redhat.com
Signed-off-by: Jeff Cody <jc...@redhat.com>
---
block/io.c | 6 ++++--
include/block/block.h | 5 +++--
2 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/block/io.c b/block/io.c
index b8845708d7..1a2272fad3 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2930,8 +2930,10 @@ static int coroutine_fn
bdrv_co_copy_range_internal(BdrvChild *src,
tracked_request_begin(&dst_req, dst->bs, dst_offset,
bytes, BDRV_TRACKED_WRITE);
- wait_serialising_requests(&src_req);
- wait_serialising_requests(&dst_req);
+ if (!(flags & BDRV_REQ_NO_SERIALISING)) {
+ wait_serialising_requests(&src_req);
+ wait_serialising_requests(&dst_req);
+ }
if (recurse_src) {
ret = src->bs->drv->bdrv_co_copy_range_from(src->bs,
src, src_offset,
diff --git a/include/block/block.h b/include/block/block.h
index 2ffc1c64c6..e5c7759a0c 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -659,13 +659,14 @@ void bdrv_unregister_buf(BlockDriverState *bs, void
*host);
* @dst: Destination child to copy data to
* @dst_offset: offset in @dst image to write data
* @bytes: number of bytes to copy
- * @flags: request flags. Must be one of:
- * 0 - actually read data from src;
+ * @flags: request flags. Supported flags:
* BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero
* write on @dst as if bdrv_co_pwrite_zeroes is
* called. Used to simplify caller code, or
* during BlockDriver.bdrv_co_copy_range_from()
* recursion.
+ * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
+ * requests currently in flight.
*
* Returns: 0 if succeeded; negative error code if failed.
**/
--
2.17.1
