Re: [PATCH 1/6] block: introduce IOCTL for zone mgmt

[Damien Le Moal <Damien.LeMoal@wdc.com>]

On 2020/06/25 21:22, Javier González wrote:
> From: Javier González <javier.gonz@samsung.com>
> 
> The current IOCTL interface for zone management is limited by struct
> blk_zone_range, which is unfortunately not extensible. Specially, the
> lack of flags is problematic for ZNS zoned devices.
> 
> This new IOCTL is designed to be a superset of the current one, with
> support for flags and bits for extensibility.
> 
> Signed-off-by: Javier González <javier.gonz@samsung.com>
> Signed-off-by: SelvaKumar S <selvakuma.s1@samsung.com>
> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
> Signed-off-by: Nitesh Shetty <nj.shetty@samsung.com>
> ---
>  block/blk-zoned.c             | 56 ++++++++++++++++++++++++++++++++++-
>  block/ioctl.c                 |  2 ++
>  include/linux/blkdev.h        |  9 ++++++
>  include/uapi/linux/blkzoned.h | 33 +++++++++++++++++++++
>  4 files changed, 99 insertions(+), 1 deletion(-)
> 
> diff --git a/block/blk-zoned.c b/block/blk-zoned.c
> index 81152a260354..e87c60004dc5 100644
> --- a/block/blk-zoned.c
> +++ b/block/blk-zoned.c
> @@ -322,7 +322,7 @@ int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
>   * BLKRESETZONE, BLKOPENZONE, BLKCLOSEZONE and BLKFINISHZONE ioctl processing.
>   * Called from blkdev_ioctl.
>   */
> -int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
> +int blkdev_zone_ops_ioctl(struct block_device *bdev, fmode_t mode,
>  			   unsigned int cmd, unsigned long arg)
>  {
>  	void __user *argp = (void __user *)arg;
> @@ -370,6 +370,60 @@ int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
>  				GFP_KERNEL);
>  }
>  
> +/*
> + * Zone management ioctl processing. Extension of blkdev_zone_ops_ioctl(), with
> + * blk_zone_mgmt structure.
> + *
> + * Called from blkdev_ioctl.
> + */
> +int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
> +			   unsigned int cmd, unsigned long arg)
> +{
> +	void __user *argp = (void __user *)arg;
> +	struct request_queue *q;
> +	struct blk_zone_mgmt zmgmt;
> +	enum req_opf op;
> +
> +	if (!argp)
> +		return -EINVAL;
> +
> +	q = bdev_get_queue(bdev);
> +	if (!q)
> +		return -ENXIO;
> +
> +	if (!blk_queue_is_zoned(q))
> +		return -ENOTTY;
> +
> +	if (!capable(CAP_SYS_ADMIN))
> +		return -EACCES;
> +
> +	if (!(mode & FMODE_WRITE))
> +		return -EBADF;
> +
> +	if (copy_from_user(&zmgmt, argp, sizeof(struct blk_zone_mgmt)))
> +		return -EFAULT;
> +
> +	switch (zmgmt.action) {
> +	case BLK_ZONE_MGMT_CLOSE:
> +		op = REQ_OP_ZONE_CLOSE;
> +		break;
> +	case BLK_ZONE_MGMT_FINISH:
> +		op = REQ_OP_ZONE_FINISH;
> +		break;
> +	case BLK_ZONE_MGMT_OPEN:
> +		op = REQ_OP_ZONE_OPEN;
> +		break;
> +	case BLK_ZONE_MGMT_RESET:
> +		op = REQ_OP_ZONE_RESET;
> +		break;
> +	default:
> +		return -ENOTTY;
> +	}
> +
> +	return blkdev_zone_mgmt(bdev, op, zmgmt.sector, zmgmt.nr_sectors,
> +				GFP_KERNEL);
> +}
> +
>  static inline unsigned long *blk_alloc_zone_bitmap(int node,
>  						   unsigned int nr_zones)
>  {
> diff --git a/block/ioctl.c b/block/ioctl.c
> index bdb3bbb253d9..0ea29754e7dd 100644
> --- a/block/ioctl.c
> +++ b/block/ioctl.c
> @@ -514,6 +514,8 @@ static int blkdev_common_ioctl(struct block_device *bdev, fmode_t mode,
>  	case BLKOPENZONE:
>  	case BLKCLOSEZONE:
>  	case BLKFINISHZONE:
> +		return blkdev_zone_ops_ioctl(bdev, mode, cmd, arg);
> +	case BLKMGMTZONE:
>  		return blkdev_zone_mgmt_ioctl(bdev, mode, cmd, arg);
>  	case BLKGETZONESZ:
>  		return put_uint(argp, bdev_zone_sectors(bdev));
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 8fd900998b4e..bd8521f94dc4 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -368,6 +368,8 @@ int blk_revalidate_disk_zones(struct gendisk *disk,
>  
>  extern int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
>  				     unsigned int cmd, unsigned long arg);
> +extern int blkdev_zone_ops_ioctl(struct block_device *bdev, fmode_t mode,
> +				  unsigned int cmd, unsigned long arg);
>  extern int blkdev_zone_mgmt_ioctl(struct block_device *bdev, fmode_t mode,
>  				  unsigned int cmd, unsigned long arg);
>  
> @@ -385,6 +387,13 @@ static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
>  	return -ENOTTY;
>  }
>  
> +
> +static inline int blkdev_zone_ops_ioctl(struct block_device *bdev, fmode_t mode,
> +					unsigned int cmd, unsigned long arg)
> +{
> +	return -ENOTTY;
> +}
> +
>  static inline int blkdev_zone_mgmt_ioctl(struct block_device *bdev,
>  					 fmode_t mode, unsigned int cmd,
>  					 unsigned long arg)
> diff --git a/include/uapi/linux/blkzoned.h b/include/uapi/linux/blkzoned.h
> index 42c3366cc25f..07b5fde21d9f 100644
> --- a/include/uapi/linux/blkzoned.h
> +++ b/include/uapi/linux/blkzoned.h
> @@ -142,6 +142,38 @@ struct blk_zone_range {
>  	__u64		nr_sectors;
>  };
>  
> +/**
> + * enum blk_zone_action - Zone state transitions managed from user-space
> + *
> + * @BLK_ZONE_MGMT_CLOSE: Transition to Closed state
> + * @BLK_ZONE_MGMT_FINISH: Transition to Finish state
> + * @BLK_ZONE_MGMT_OPEN: Transition to Open state
> + * @BLK_ZONE_MGMT_RESET: Transition to Reset state
> + */
> +enum blk_zone_action {
> +	BLK_ZONE_MGMT_CLOSE	= 0x1,
> +	BLK_ZONE_MGMT_FINISH	= 0x2,
> +	BLK_ZONE_MGMT_OPEN	= 0x3,
> +	BLK_ZONE_MGMT_RESET	= 0x4,
> +};
> +
> +/**
> + * struct blk_zone_mgmt - Extended zoned management
> + *
> + * @action: Zone action as in described in enum blk_zone_action
> + * @flags: Flags for the action
> + * @sector: Starting sector of the first zone to operate on
> + * @nr_sectors: Total number of sectors of all zones to operate on
> + */
> +struct blk_zone_mgmt {
> +	__u8		action;
> +	__u8		resv3[3];
> +	__u32		flags;
> +	__u64		sector;
> +	__u64		nr_sectors;
> +	__u64		resv31;
> +};
> +
>  /**
>   * Zoned block device ioctl's:
>   *
> @@ -166,5 +198,6 @@ struct blk_zone_range {
>  #define BLKOPENZONE	_IOW(0x12, 134, struct blk_zone_range)
>  #define BLKCLOSEZONE	_IOW(0x12, 135, struct blk_zone_range)
>  #define BLKFINISHZONE	_IOW(0x12, 136, struct blk_zone_range)
> +#define BLKMGMTZONE	_IOR(0x12, 137, struct blk_zone_mgmt)
>  
>  #endif /* _UAPI_BLKZONED_H */
> 

Without defining what the flags can be, it is hard to judge what will change
from the current distinct ioctls.


-- 
Damien Le Moal
Western Digital Research