Re: [PATCH 7/9] target: Enable WRITE_INSERT emulation in target_execute_cmd

[Sagi Grimberg <sagig@dev.mellanox.co.il>]

On 4/3/2014 12:35 PM, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
>
> This patch enables WRITE_INSERT emulation in target_execute_cmd()
> in order to locally generate DIF PI before submitting the WRITE
> to the underlying backend device.
>
> This is required for fabric drivers that currently don't support
> DIF over-the-wire, in order to inact with backend devices that
> have hardware (IBLOCK) or software (FILEIO + RAMDISK) support
> for handling T10 PI.
>
> Cc: Martin K. Petersen <martin.petersen@oracle.com>
> Cc: Sagi Grimberg <sagig@mellanox.com>
> Cc: Or Gerlitz <ogerlitz@mellanox.com>
> Cc: Quinn Tran <quinn.tran@qlogic.com>
> Cc: Giridhar Malavali <giridhar.malavali@qlogic.com>
> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
> ---
>   drivers/target/target_core_transport.c |    9 +++++++++
>   1 file changed, 9 insertions(+)
>
> diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
> index 9c820ba..530a9e8 100644
> --- a/drivers/target/target_core_transport.c
> +++ b/drivers/target/target_core_transport.c
> @@ -1767,6 +1767,15 @@ void target_execute_cmd(struct se_cmd *cmd)
>   	cmd->t_state = TRANSPORT_PROCESSING;
>   	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
>   	spin_unlock_irq(&cmd->t_state_lock);
> +	/*
> +	 * Perform WRITE_INSERT of PI using software emulation when backend
> +	 * device has PI enabled, if the transport has not already generated
> +	 * PI using hardware WRITE_INSERT offload.
> +	 */
> +	if (cmd->prot_op == TARGET_PROT_DOUT_INSERT) {
> +		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
> +			sbc_dif_write_insert(cmd);
> +	}
>   
>   	if (target_handle_task_attr(cmd)) {
>   		spin_lock_irq(&cmd->t_state_lock);
Looks good to me.

Reviewed-by: Sagi Grimberg <sagig@mellanox.com>

This is useless though without the code setting this prot_op in 
sbc_set_prot_op_checks()...