From: Nicholas Bellinger <n...@linux-iscsi.org> This patch adds a special BlockDriverState->sg check in block.c:find_image_format() after bdrv_file_open() -> block/raw-posix.c:hdev_open() has been called to determine if we are dealing with a Linux host scsi-generic device or not.
The patch then returns the BlockDriver * from find_protocol(), skipping the subsequent bdrv_read() and rest of find_image_format(). Signed-off-by: Nicholas A. Bellinger <n...@linux-iscsi.org> --- block.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/block.c b/block.c index 48305b7..02a22f6 100644 --- a/block.c +++ b/block.c @@ -332,6 +332,13 @@ static BlockDriver *find_image_format(const char *filename) ret = bdrv_file_open(&bs, filename, 0); if (ret < 0) return NULL; + /* + * For scsi-generic we skip the read and return *drv from + * find_protocol(). + */ + if (bs->sg) + return drv; + ret = bdrv_pread(bs, 0, buf, sizeof(buf)); bdrv_delete(bs); if (ret < 0) { -- 1.5.6.5