[03/10] scsi: move command size detection out of the fast path

Message ID 20201005084130.143273-4-hch@lst.de
State New
Headers show
Series
  • [01/10] scsi: don't export scsi_device_from_queue
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Commit Message

Christoph Hellwig Oct. 5, 2020, 8:41 a.m.
We only need to detect the command size for ioctl request from userspace,
which is limited to the passthrough path.  Move the check there instead
of doing it for all queuecommand invocations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/scsi_lib.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Hannes Reinecke Oct. 5, 2020, 9:02 a.m. | #1
On 10/5/20 10:41 AM, Christoph Hellwig wrote:
> We only need to detect the command size for ioctl request from userspace,
> which is limited to the passthrough path.  Move the check there instead
> of doing it for all queuecommand invocations.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   drivers/scsi/scsi_lib.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index 8a7ae46b5943da..3c551f06ebe9be 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -1166,6 +1166,8 @@ static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev,
>   	}
>   
>   	cmd->cmd_len = scsi_req(req)->cmd_len;
> +	if (cmd->cmd_len == 0)
> +		cmd->cmd_len = scsi_command_size(cmd->cmnd);
>   	cmd->cmnd = scsi_req(req)->cmd;
>   	cmd->transfersize = blk_rq_bytes(req);
>   	cmd->allowed = scsi_req(req)->retries;
> @@ -1685,8 +1687,6 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
>   
>   	scsi_set_resid(cmd, 0);
>   	memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
> -	if (cmd->cmd_len == 0)
> -		cmd->cmd_len = scsi_command_size(cmd->cmnd);
>   	cmd->scsi_done = scsi_mq_done;
>   
>   	reason = scsi_dispatch_cmd(cmd);
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes

Patch

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 8a7ae46b5943da..3c551f06ebe9be 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1166,6 +1166,8 @@  static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev,
 	}
 
 	cmd->cmd_len = scsi_req(req)->cmd_len;
+	if (cmd->cmd_len == 0)
+		cmd->cmd_len = scsi_command_size(cmd->cmnd);
 	cmd->cmnd = scsi_req(req)->cmd;
 	cmd->transfersize = blk_rq_bytes(req);
 	cmd->allowed = scsi_req(req)->retries;
@@ -1685,8 +1687,6 @@  static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
 
 	scsi_set_resid(cmd, 0);
 	memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
-	if (cmd->cmd_len == 0)
-		cmd->cmd_len = scsi_command_size(cmd->cmnd);
 	cmd->scsi_done = scsi_mq_done;
 
 	reason = scsi_dispatch_cmd(cmd);