Commit 112ff512 authored by Stefan Haberland's avatar Stefan Haberland Committed by Jens Axboe
Browse files

s390/dasd: add ioctl to perform a swap of the drivers copy pair 



The newly defined ioctl BIODASDCOPYPAIRSWAP takes a structure that
specifies a copy pair that should be swapped. It will call the device
discipline function to perform the swap operation.

The structure looks as followed:

struct dasd_copypair_swap_data_t {
       char primary[20];
       char secondary[20];
       __u8 reserved[64];
};

where primary is the old primary device that will be replaced by the
secondary device. The old primary will become a secondary device
afterwards.

Signed-off-by: default avatarStefan Haberland <sth@linux.ibm.com>
Reviewed-by: default avatarJan Hoeppner <hoeppner@linux.ibm.com>
Link: https://lore.kernel.org/r/20220920192616.808070-6-sth@linux.ibm.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 413862ca

arch/s390/include/uapi/asm/dasd.h

+14 −0
Original line number Diff line number Diff line
@@ -182,6 +182,18 @@ typedef struct format_data_t { 
	unsigned int intensity;

} format_data_t;



/*

 * struct dasd_copypair_swap_data_t

 * represents all data necessary to issue a swap of the copy pair relation

 */

struct dasd_copypair_swap_data_t {

	char primary[20]; /* BUSID of primary */

	char secondary[20]; /* BUSID of secondary */



	/* Reserved for future updates. */

	__u8 reserved[64];

};



/*

 * values to be used for format_data_t.intensity

 * 0/8: normal format
@@ -326,6 +338,8 @@ struct dasd_snid_ioctl_data { 
#define BIODASDSATTR   _IOW(DASD_IOCTL_LETTER,2,attrib_data_t)

/* Release Allocated Space */

#define BIODASDRAS     _IOW(DASD_IOCTL_LETTER, 3, format_data_t)

/* Swap copy pair relation */

#define BIODASDCOPYPAIRSWAP _IOW(DASD_IOCTL_LETTER, 4, struct dasd_copypair_swap_data_t)



/* Get Sense Path Group ID (SNID) data */

#define BIODASDSNID    _IOWR(DASD_IOCTL_LETTER, 1, struct dasd_snid_ioctl_data)

drivers/s390/block/dasd_ioctl.c

+53 −0
Original line number Diff line number Diff line
@@ -379,6 +379,56 @@ static int dasd_ioctl_release_space(struct block_device *bdev, void __user *argp 
	return rc;

}



/*

 * Swap driver iternal copy relation.

 */

static int

dasd_ioctl_copy_pair_swap(struct block_device *bdev, void __user *argp)

{

	struct dasd_copypair_swap_data_t data;

	struct dasd_device *device;

	int rc;



	if (!capable(CAP_SYS_ADMIN))

		return -EACCES;



	device = dasd_device_from_gendisk(bdev->bd_disk);

	if (!device)

		return -ENODEV;



	if (copy_from_user(&data, argp, sizeof(struct dasd_copypair_swap_data_t))) {

		dasd_put_device(device);

		return -EFAULT;

	}

	if (memchr_inv(data.reserved, 0, sizeof(data.reserved))) {

		pr_warn("%s: Ivalid swap data specified.\n",

			dev_name(&device->cdev->dev));

		dasd_put_device(device);

		return DASD_COPYPAIRSWAP_INVALID;

	}

	if (bdev_is_partition(bdev)) {

		pr_warn("%s: The specified DASD is a partition and cannot be swapped\n",

			dev_name(&device->cdev->dev));

		dasd_put_device(device);

		return DASD_COPYPAIRSWAP_INVALID;

	}

	if (!device->copy) {

		pr_warn("%s: The specified DASD has no copy pair set up\n",

			dev_name(&device->cdev->dev));

		dasd_put_device(device);

		return -ENODEV;

	}

	if (!device->discipline->copy_pair_swap) {

		dasd_put_device(device);

		return -EOPNOTSUPP;

	}

	rc = device->discipline->copy_pair_swap(device, data.primary,

						data.secondary);

	dasd_put_device(device);



	return rc;

}



#ifdef CONFIG_DASD_PROFILE

/*

 * Reset device profile information
@@ -637,6 +687,9 @@ int dasd_ioctl(struct block_device *bdev, fmode_t mode, 
	case BIODASDRAS:

		rc = dasd_ioctl_release_space(bdev, argp);

		break;

	case BIODASDCOPYPAIRSWAP:

		rc = dasd_ioctl_copy_pair_swap(bdev, argp);

		break;

	default:

		/* if the discipline has an ioctl method try it. */

		rc = -ENOTTY;