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Commit 196339f1 authored by Stefan Weinhuber's avatar Stefan Weinhuber Committed by Martin Schwidefsky
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[S390] dasd: provide a Sense Path Group ID ioctl 



The BIODASDSNID ioctl executes a 'Sense Path Group ID'
command on a DASD ECKD device. The returned path group data
allows user space programs to determine path state and
path group ID of the channel paths to the device.

Signed-off-by: default avatarStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent b25c477b

arch/s390/include/asm/dasd.h

+22 −18
Original line number Diff line number Diff line
@@ -217,6 +217,25 @@ typedef struct dasd_symmio_parms { 
	int rssd_result_len;

} __attribute__ ((packed)) dasd_symmio_parms_t;



/*

 * Data returned by Sense Path Group ID (SNID)

 */

struct dasd_snid_data {

	struct {

		__u8 group:2;

		__u8 reserve:2;

		__u8 mode:1;

		__u8 res:3;

	} __attribute__ ((packed)) path_state;

	__u8 pgid[11];

} __attribute__ ((packed));



struct dasd_snid_ioctl_data {

	struct dasd_snid_data data;

	__u8 path_mask;

} __attribute__ ((packed));





/********************************************************************************

 * SECTION: Definition of IOCTLs

 *
@@ -261,25 +280,10 @@ typedef struct dasd_symmio_parms { 
/* Set Attributes (cache operations) */

#define BIODASDSATTR   _IOW(DASD_IOCTL_LETTER,2,attrib_data_t) 



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

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



#define BIODASDSYMMIO  _IOWR(DASD_IOCTL_LETTER, 240, dasd_symmio_parms_t)



#endif				/* DASD_H */

/*

 * Overrides for Emacs so that we follow Linus's tabbing style.

 * Emacs will notice this stuff at the end of the file and automatically

 * adjust the settings for this buffer only.  This must remain at the end

 * of the file.

 * ---------------------------------------------------------------------------

 * Local variables:

 * c-indent-level: 4 

 * c-brace-imaginary-offset: 0

 * c-brace-offset: -4

 * c-argdecl-indent: 4

 * c-label-offset: -4

 * c-continued-statement-offset: 4

 * c-continued-brace-offset: 0

 * indent-tabs-mode: nil

 * tab-width: 8

 * End:

 */

drivers/s390/block/dasd_eckd.c

+69 −0
Original line number Diff line number Diff line
@@ -2801,6 +2801,73 @@ dasd_eckd_steal_lock(struct dasd_device *device) 
	return rc;

}



/*

 * SNID - Sense Path Group ID

 * This ioctl may be used in situations where I/O is stalled due to

 * a reserve, so if the normal dasd_smalloc_request fails, we use the

 * preallocated dasd_reserve_req.

 */

static int dasd_eckd_snid(struct dasd_device *device,

			  void __user *argp)

{

	struct dasd_ccw_req *cqr;

	int rc;

	struct ccw1 *ccw;

	int useglobal;

	struct dasd_snid_ioctl_data usrparm;



	if (!capable(CAP_SYS_ADMIN))

		return -EACCES;



	if (copy_from_user(&usrparm, argp, sizeof(usrparm)))

		return -EFAULT;



	useglobal = 0;

	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1,

				   sizeof(struct dasd_snid_data), device);

	if (IS_ERR(cqr)) {

		mutex_lock(&dasd_reserve_mutex);

		useglobal = 1;

		cqr = &dasd_reserve_req->cqr;

		memset(cqr, 0, sizeof(*cqr));

		memset(&dasd_reserve_req->ccw, 0,

		       sizeof(dasd_reserve_req->ccw));

		cqr->cpaddr = &dasd_reserve_req->ccw;

		cqr->data = &dasd_reserve_req->data;

		cqr->magic = DASD_ECKD_MAGIC;

	}

	ccw = cqr->cpaddr;

	ccw->cmd_code = DASD_ECKD_CCW_SNID;

	ccw->flags |= CCW_FLAG_SLI;

	ccw->count = 12;

	ccw->cda = (__u32)(addr_t) cqr->data;

	cqr->startdev = device;

	cqr->memdev = device;

	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);

	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);

	cqr->retries = 5;

	cqr->expires = 10 * HZ;

	cqr->buildclk = get_clock();

	cqr->status = DASD_CQR_FILLED;

	cqr->lpm = usrparm.path_mask;



	rc = dasd_sleep_on_immediatly(cqr);

	/* verify that I/O processing didn't modify the path mask */

	if (!rc && usrparm.path_mask && (cqr->lpm != usrparm.path_mask))

		rc = -EIO;

	if (!rc) {

		usrparm.data = *((struct dasd_snid_data *)cqr->data);

		if (copy_to_user(argp, &usrparm, sizeof(usrparm)))

			rc = -EFAULT;

	}



	if (useglobal)

		mutex_unlock(&dasd_reserve_mutex);

	else

		dasd_sfree_request(cqr, cqr->memdev);

	return rc;

}



/*

 * Read performance statistics

 */
@@ -3036,6 +3103,8 @@ dasd_eckd_ioctl(struct dasd_block *block, unsigned int cmd, void __user *argp) 
		return dasd_eckd_reserve(device);

	case BIODASDSLCK:

		return dasd_eckd_steal_lock(device);

	case BIODASDSNID:

		return dasd_eckd_snid(device, argp);

	case BIODASDSYMMIO:

		return dasd_symm_io(device, argp);

	default:

drivers/s390/block/dasd_eckd.h

+1 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#define DASD_ECKD_CCW_WRITE_CKD		 0x1d

#define DASD_ECKD_CCW_READ_CKD		 0x1e

#define DASD_ECKD_CCW_PSF		 0x27

#define DASD_ECKD_CCW_SNID		 0x34

#define DASD_ECKD_CCW_RSSD		 0x3e

#define DASD_ECKD_CCW_LOCATE_RECORD	 0x47

#define DASD_ECKD_CCW_SNSS		 0x54