On Wed, Mar 07, 2018 at 08:29:03PM +0800, Jianchao Wang wrote:
> iscsi tcp will first send out data, then calculate and send data
> digest. If we don't have BDI_CAP_STABLE_WRITES, the page cache will
> be written in spite of the on going writeback. Consequently, wrong
> digest will be got and sent to target.
>
> To fix this, set BDI_CAP_STABLE_WRITES when data digest is enabled
> in iscsi_tcp .slave_configure callback.
>
> Signed-off-by: Jianchao Wang <jianchao.w.w...@oracle.com>
> ---
> drivers/scsi/iscsi_tcp.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
> index 6198559..261c686 100644
> --- a/drivers/scsi/iscsi_tcp.c
> +++ b/drivers/scsi/iscsi_tcp.c
> @@ -37,6 +37,7 @@
> #include <linux/kfifo.h>
> #include <linux/scatterlist.h>
> #include <linux/module.h>
> +#include <linux/backing-dev.h>
> #include <net/tcp.h>
> #include <scsi/scsi_cmnd.h>
> #include <scsi/scsi_device.h>
> @@ -954,6 +955,12 @@ static int iscsi_sw_tcp_slave_alloc(struct scsi_device
> *sdev)
>
> static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
> {
> + struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(sdev->host);
> + struct iscsi_session *session = tcp_sw_host->session;
> + struct iscsi_conn *conn = session->leadconn;
> +
> + if (conn->datadgst_en)
> + sdev->request_queue->backing_dev_info->capabilities |=
> BDI_CAP_STABLE_WRITES;
> blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
> blk_queue_dma_alignment(sdev->request_queue, 0);
> return 0;
> --
Thanks for fixing this issue with data digests!
Signed-off-by: Chris Leech <cle...@redhat.com>
