FUJITA Tomonori wrote:
> st_scsi_kern_execute is a helper function to perform SCSI commands
> synchronously. It supports data transfer with a liner in-kernel buffer
> (not scatter gather). st_scsi_kern_execute internally uses
> blk_get_request, blk_rq_map_kern, and blk_execute_rq.
>
> The majority of st_do_scsi can be replaced with
> st_scsi_kern_execute. This is a preparation for rewriting st_do_scsi
> to remove obsolete scsi_execute_async().
>
> Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
> ---
> drivers/scsi/st.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 49 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
> index 878493d..6179940 100644
> --- a/drivers/scsi/st.c
> +++ b/drivers/scsi/st.c
> @@ -533,6 +533,55 @@ st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd
> return SRpnt;
> }
>
> +static int st_scsi_kern_execute(struct st_request *streq,
> + const unsigned char *cmd, int data_direction,
> + void *buffer, unsigned bufflen, int timeout,
> + int retries)
> +{
> + struct scsi_tape *stp = streq->stp;
> + struct request *req;
> + int write = (data_direction == DMA_TO_DEVICE);
> + int ret = 0;
> +
> + /* st_do_scsi returns -EBUSY in case of OOM */
> + req = blk_get_request(stp->device->request_queue, write, GFP_KERNEL);
> + if (!req)
> + return -EBUSY;
> +
> + if (bufflen) {
> + ret = blk_rq_map_kern(stp->device->request_queue, req,
> + buffer, bufflen, GFP_KERNEL);
> + if (ret)
> + goto out;
> + }
> +
> + req->cmd_type = REQ_TYPE_BLOCK_PC;
> + req->cmd_flags |= REQ_QUIET;
> +
> + req->cmd_len = COMMAND_SIZE(cmd[0]);
> + memcpy(req->cmd, cmd, req->cmd_len);
> +
> + req->sense = streq->sense;
> + req->sense_len = 0;
> +
> + req->timeout = timeout;
> + req->retries = retries;
> +
> + stp->buffer->cmdstat.have_sense = 0;
> + memcpy(streq->cmd, cmd, sizeof(streq->cmd));
> +
> + blk_execute_rq(req->q, NULL, req, 1);
> +
> + stp->buffer->cmdstat.midlevel_result = streq->result = req->errors;
> + stp->buffer->cmdstat.residual = req->data_len;
> +
TOMO Hi.
would you say that the only reason we cannot use scsi_execute inside st_scsi_kern_execute
is because we don't have residual count returned from scsi_execute ?
> + stp->buffer->syscall_result = st_chk_result(stp, streq);
> +
> +out:
> + blk_put_request(req);
> +
> + return ret;
> +}
>
> /* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
> write has been correct but EOM early warning reached, -EIO if write ended in
The reason I'm asking is because I needed the same from scsi_execute in the passed.
Boaz
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