From: Roman Kagan <rka...@parallels.com>
Add backing file support to Parallels format driver.
That said, I think backing file operations should end up in the generic
block layer, but that's a longer story...
Signed-off-by: Roman Kagan <rka...@parallels.com>
Signed-off-by: Denis V. Lunev <d...@openvz.org>
CC: Jeff Cody <jc...@redhat.com>
CC: Kevin Wolf <kw...@redhat.com>
CC: Stefan Hajnoczi <stefa...@redhat.com>
---
block/parallels.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/block/parallels.c b/block/parallels.c
index 2d3e962..718274b 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -419,6 +419,11 @@ static int parallels_read(BlockDriverState *bs, int64_t
sector_num,
if (ret < 0) {
return ret;
}
+ } else if (bs->backing_hd) {
+ int ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
+ if (ret < 0) {
+ return ret;
+ }
} else {
memset(buf, 0, n << BDRV_SECTOR_BITS);
}
@@ -454,6 +459,7 @@ static BlockDriver bdrv_parallels = {
.bdrv_read = parallels_co_read,
.bdrv_close = parallels_close,
.bdrv_co_get_block_status = parallels_co_get_block_status,
+ .supports_backing = true,
};
static void bdrv_parallels_init(void)
--
1.9.1
