On 08/05/2015 13:38, Dimitris Aragiorgis wrote:
> During migration, QEMU uses fsync()/fdatasync() on the open file
> descriptor for read-write block devices to flush data just before
> stopping the VM.
>
> However, fsync() on a scsi-generic device returns -EINVAL which
> causes the migration to fail. This patch skips flushing data in case
> of an SG device, since submitting SCSI commands directly via an SG
> character device (e.g. /dev/sg0) bypasses the page cache completely,
> anyway.
Good catch! The patch is correct, but please remove the same test from
iscsi_co_flush (in block/iscsi.c) because it's now duplicate.
Thanks,
Paolo
> Signed-off-by: Dimitris Aragiorgis <dim...@arrikto.com>
> ---
> block/io.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/block/io.c b/block/io.c
> index 1ce62c4..d248a4d 100644
> --- a/block/io.c
> +++ b/block/io.c
> @@ -2231,7 +2231,7 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
> {
> int ret;
>
> - if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
> + if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs) ||
> bdrv_is_sg(bs)) {
> return 0;
> }
>
>
