From: Pavel Dovgalyuk <pavel.dovga...@ispras.ru>
This patch adds callback for flush request. This callback is responsible
for flushing whole block devices stack. bdrv_flush function does not
proceed to underlying devices. It should be performed by this callback
function, if needed.
Signed-off-by: Pavel Dovgalyuk <pavel.dovga...@ispras.ru>
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
block/io.c | 7 +++++++
include/block/block_int.h | 7 +++++++
2 files changed, 14 insertions(+)
diff --git a/block/io.c b/block/io.c
index bfc8592..c447db2 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2331,6 +2331,13 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
}
tracked_request_begin(&req, bs, 0, 0, BDRV_TRACKED_FLUSH);
+
+ /* Write back all layers by calling one driver function */
+ if (bs->drv->bdrv_co_flush) {
+ ret = bs->drv->bdrv_co_flush(bs);
+ goto out;
+ }
+
/* Write back cached data to the OS even with cache=unsafe */
BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS);
if (bs->drv->bdrv_co_flush_to_os) {
diff --git a/include/block/block_int.h b/include/block/block_int.h
index a33b0de..1177c25 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -176,6 +176,13 @@ struct BlockDriver {
int (*bdrv_inactivate)(BlockDriverState *bs);
/*
+ * Flushes all data for all layers by calling bdrv_co_flush for underlying
+ * layers, if needed. This function is needed for deterministic
+ * synchronization of the flush finishing callback.
+ */
+ int coroutine_fn (*bdrv_co_flush)(BlockDriverState *bs);
+
+ /*
* Flushes all data that was already written to the OS all the way down to
* the disk (for example raw-posix calls fsync()).
*/
--
1.8.3.1
