Re: [PATCH v3 03/19] scsi: Move sd_pr_type to header to share

[Chaitanya Kulkarni <chaitanyak@nvidia.com>]

On 10/26/22 16:19, Mike Christie wrote:
> LIO is going to want to do the same block to/from SCSI pr types as sd.c
> so this moves the sd_pr_type helper to a new file. The next patch will
> then also add a helper to go from the SCSI value to the block one for use
> with PERSISTENT_RESERVE_IN commands.
> 
> Signed-off-by: Mike Christie <michael.christie@oracle.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> ---
>   drivers/scsi/sd.c            | 31 +++++++------------------------
>   include/scsi/scsi_block_pr.h | 36 ++++++++++++++++++++++++++++++++++++
>   2 files changed, 43 insertions(+), 24 deletions(-)
>   create mode 100644 include/scsi/scsi_block_pr.h
> 
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index 4dc5c932fbd3..ad9374b07585 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -67,6 +67,7 @@
>   #include <scsi/scsi_host.h>
>   #include <scsi/scsi_ioctl.h>
>   #include <scsi/scsicam.h>
> +#include <scsi/scsi_block_pr.h>
>   
>   #include "sd.h"
>   #include "scsi_priv.h"
> @@ -1694,28 +1695,8 @@ static int sd_get_unique_id(struct gendisk *disk, u8 id[16],
>   	return ret;
>   }
>   
> -static char sd_pr_type(enum pr_type type)
> -{
> -	switch (type) {
> -	case PR_WRITE_EXCLUSIVE:
> -		return 0x01;
> -	case PR_EXCLUSIVE_ACCESS:
> -		return 0x03;
> -	case PR_WRITE_EXCLUSIVE_REG_ONLY:
> -		return 0x05;
> -	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
> -		return 0x06;
> -	case PR_WRITE_EXCLUSIVE_ALL_REGS:
> -		return 0x07;
> -	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
> -		return 0x08;
> -	default:
> -		return 0;
> -	}
> -};
> -
>   static int sd_pr_out_command(struct block_device *bdev, u8 sa,
> -		u64 key, u64 sa_key, u8 type, u8 flags)
> +		u64 key, u64 sa_key, enum scsi_pr_type type, u8 flags)
>   {
>   	struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
>   	struct scsi_device *sdev = sdkp->device;
> @@ -1778,19 +1759,21 @@ static int sd_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
>   {
>   	if (flags)
>   		return -EOPNOTSUPP;
> -	return sd_pr_out_command(bdev, 0x01, key, 0, sd_pr_type(type), 0);
> +	return sd_pr_out_command(bdev, 0x01, key, 0,
> +				 block_pr_type_to_scsi(type), 0);
>   }
>   
>   static int sd_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
>   {
> -	return sd_pr_out_command(bdev, 0x02, key, 0, sd_pr_type(type), 0);
> +	return sd_pr_out_command(bdev, 0x02, key, 0,
> +				 block_pr_type_to_scsi(type), 0);
>   }
>   
>   static int sd_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
>   		enum pr_type type, bool abort)
>   {
>   	return sd_pr_out_command(bdev, abort ? 0x05 : 0x04, old_key, new_key,
> -			     sd_pr_type(type), 0);
> +				 block_pr_type_to_scsi(type), 0);
>   }
>   
>   static int sd_pr_clear(struct block_device *bdev, u64 key)
> diff --git a/include/scsi/scsi_block_pr.h b/include/scsi/scsi_block_pr.h
> new file mode 100644
> index 000000000000..6e99f844330d
> --- /dev/null
> +++ b/include/scsi/scsi_block_pr.h
> @@ -0,0 +1,36 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _SCSI_BLOCK_PR_H
> +#define _SCSI_BLOCK_PR_H
> +
> +#include <uapi/linux/pr.h>
> +
> +enum scsi_pr_type {
> +	SCSI_PR_WRITE_EXCLUSIVE			= 0x01,
> +	SCSI_PR_EXCLUSIVE_ACCESS		= 0x03,
> +	SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY	= 0x05,
> +	SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY	= 0x06,
> +	SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS	= 0x07,
> +	SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS	= 0x08,
> +};
> +
> +static inline enum scsi_pr_type block_pr_type_to_scsi(enum pr_type type)
> +{
> +	switch (type) {
> +	case PR_WRITE_EXCLUSIVE:
> +		return SCSI_PR_WRITE_EXCLUSIVE;
> +	case PR_EXCLUSIVE_ACCESS:
> +		return SCSI_PR_EXCLUSIVE_ACCESS;
> +	case PR_WRITE_EXCLUSIVE_REG_ONLY:
> +		return SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY;
> +	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
> +		return SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY;
> +	case PR_WRITE_EXCLUSIVE_ALL_REGS:
> +		return SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS;
> +	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
> +		return SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS;
> +	default:
> +		return 0;
> +	}
> +};


do we need above semicolon ?

how about not using switch case pattern totally untested below ?

static inline enum scsi_pr_type block_pr_type_to_scsi(enum pr_type type)
{
         enum pr_type pr_to_scsi_pr[] = {
                 [PR_WRITE_EXCLUSIVE] = SCSI_PR_WRITE_EXCLUSIVE,
                 [PR_EXCLUSIVE_ACCESS] = SCSI_PR_EXCLUSIVE_ACCESS,
                 [PR_WRITE_EXCLUSIVE_REG_ONLY] = 
SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY,
                 [PR_EXCLUSIVE_ACCESS_REG_ONLY] = 
SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY,
                 [PR_WRITE_EXCLUSIVE_ALL_REGS] = 
SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS,
                 [PR_EXCLUSIVE_ACCESS_ALL_REGS] = 
SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS,
         };

         if (type > ARRAY_SIZE(pr_to_scsi_pr))
                 return 0;
         return pr_to_scsi_pr[type];
}


-ck