block: add interface to toggle copy-on-read
The bdrv_enable_copy_on_read()/bdrv_disable_copy_on_read() functions can
be used to programmatically enable or disable copy-on-read for a block
device. Later patches add the actual copy-on-read logic.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block.h b/block.h
index 8482dbc..5f8a98a 100644
--- a/block.h
+++ b/block.h
@@ -70,6 +70,7 @@
#define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */
#define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */
#define BDRV_O_NO_FLUSH 0x0200 /* disable flushing on this disk */
+#define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
#define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH)
@@ -312,6 +313,9 @@
int nr_sectors);
int64_t bdrv_get_dirty_count(BlockDriverState *bs);
+void bdrv_enable_copy_on_read(BlockDriverState *bs);
+void bdrv_disable_copy_on_read(BlockDriverState *bs);
+
void bdrv_set_in_use(BlockDriverState *bs, int in_use);
int bdrv_in_use(BlockDriverState *bs);
