Commit c32b82af authored Mar 14, 2016 by Pavel Dovgalyuk Committed by Kevin Wolf Mar 30, 2016

block: add flush callback



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.dovgaluk@ispras.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

parent 6278ae03

block/io.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -2333,6 +2333,13 @@ 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) {

include/block/block_int.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -175,6 +175,13 @@ struct BlockDriver {
		void (bdrv_invalidate_cache)(BlockDriverState bs, Error **errp);
		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()).