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Commit b206181d authored by Stefan Haberland's avatar Stefan Haberland Committed by Martin Schwidefsky
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[S390] dasd: add sanity check to detect path connection error 



Prevents possible data corruption by detecting cabling error.
Therefor read and compare the UID for all available channel paths.

Signed-off-by: default avatarStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent e58b0d90

drivers/s390/block/dasd_eckd.c

+300 −109
Original line number Diff line number Diff line
@@ -752,24 +752,13 @@ dasd_eckd_cdl_reclen(int recid) 
		return sizes_trk0[recid];

	return LABEL_SIZE;

}



/*

 * Generate device unique id that specifies the physical device.

 */

static int dasd_eckd_generate_uid(struct dasd_device *device)

/* create unique id from private structure. */

static void create_uid(struct dasd_eckd_private *private)

{

	struct dasd_eckd_private *private;

	struct dasd_uid *uid;

	int count;

	unsigned long flags;

	struct dasd_uid *uid;



	private = (struct dasd_eckd_private *) device->private;

	if (!private)

		return -ENODEV;

	if (!private->ned || !private->gneq)

		return -ENODEV;

	uid = &private->uid;

	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);

	memset(uid, 0, sizeof(struct dasd_uid));

	memcpy(uid->vendor, private->ned->HDA_manufacturer,

	       sizeof(uid->vendor) - 1);
@@ -792,6 +781,23 @@ static int dasd_eckd_generate_uid(struct dasd_device *device) 
				private->vdsneq->uit[count]);

		}

	}

}



/*

 * Generate device unique id that specifies the physical device.

 */

static int dasd_eckd_generate_uid(struct dasd_device *device)

{

	struct dasd_eckd_private *private;

	unsigned long flags;



	private = (struct dasd_eckd_private *) device->private;

	if (!private)

		return -ENODEV;

	if (!private->ned || !private->gneq)

		return -ENODEV;

	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);

	create_uid(private);

	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);

	return 0;

}
@@ -811,6 +817,21 @@ static int dasd_eckd_get_uid(struct dasd_device *device, struct dasd_uid *uid) 
	return -EINVAL;

}



/*

 * compare device UID with data of a given dasd_eckd_private structure

 * return 0 for match

 */

static int dasd_eckd_compare_path_uid(struct dasd_device *device,

				      struct dasd_eckd_private *private)

{

	struct dasd_uid device_uid;



	create_uid(private);

	dasd_eckd_get_uid(device, &device_uid);



	return memcmp(&device_uid, &private->uid, sizeof(struct dasd_uid));

}



static void dasd_eckd_fill_rcd_cqr(struct dasd_device *device,

				   struct dasd_ccw_req *cqr,

				   __u8 *rcd_buffer,
@@ -1005,17 +1026,19 @@ static int dasd_eckd_read_conf(struct dasd_device *device) 
	int conf_len, conf_data_saved;

	int rc;

	__u8 lpm, opm;

	struct dasd_eckd_private *private;

	struct dasd_eckd_private *private, path_private;

	struct dasd_path *path_data;

	struct dasd_uid *uid;

	char print_path_uid[60], print_device_uid[60];



	private = (struct dasd_eckd_private *) device->private;

	path_data = &device->path_data;

	opm = ccw_device_get_path_mask(device->cdev);

	lpm = 0x80;

	conf_data_saved = 0;

	/* get configuration data per operational path */

	for (lpm = 0x80; lpm; lpm>>= 1) {

		if (lpm & opm) {

		if (!(lpm & opm))

			continue;

		rc = dasd_eckd_read_conf_lpm(device, &conf_data,

					     &conf_len, lpm);

		if (rc && rc != -EOPNOTSUPP) {	/* -EOPNOTSUPP is ok */
@@ -1043,7 +1066,65 @@ static int dasd_eckd_read_conf(struct dasd_device *device) 
				kfree(conf_data);

				continue;

			}

			/*

			 * build device UID that other path data

			 * can be compared to it

			 */

			dasd_eckd_generate_uid(device);

			conf_data_saved++;

		} else {

			path_private.conf_data = conf_data;

			path_private.conf_len = DASD_ECKD_RCD_DATA_SIZE;

			if (dasd_eckd_identify_conf_parts(

				    &path_private)) {

				path_private.conf_data = NULL;

				path_private.conf_len = 0;

				kfree(conf_data);

				continue;

			}



			if (dasd_eckd_compare_path_uid(

				    device, &path_private)) {

				uid = &path_private.uid;

				if (strlen(uid->vduit) > 0)

					snprintf(print_path_uid,

						 sizeof(print_path_uid),

						 "%s.%s.%04x.%02x.%s",

						 uid->vendor, uid->serial,

						 uid->ssid, uid->real_unit_addr,

						 uid->vduit);

				else

					snprintf(print_path_uid,

						 sizeof(print_path_uid),

						 "%s.%s.%04x.%02x",

						 uid->vendor, uid->serial,

						 uid->ssid,

						 uid->real_unit_addr);

				uid = &private->uid;

				if (strlen(uid->vduit) > 0)

					snprintf(print_device_uid,

						 sizeof(print_device_uid),

						 "%s.%s.%04x.%02x.%s",

						 uid->vendor, uid->serial,

						 uid->ssid, uid->real_unit_addr,

						 uid->vduit);

				else

					snprintf(print_device_uid,

						 sizeof(print_device_uid),

						 "%s.%s.%04x.%02x",

						 uid->vendor, uid->serial,

						 uid->ssid,

						 uid->real_unit_addr);

				dev_err(&device->cdev->dev,

					"Not all channel paths lead to "

					"the same device, path %02X leads to "

					"device %s instead of %s\n", lpm,

					print_path_uid, print_device_uid);

				return -EINVAL;

			}



			path_private.conf_data = NULL;

			path_private.conf_len = 0;

		}

		switch (dasd_eckd_path_access(conf_data, conf_len)) {

		case 0x02:
@@ -1054,10 +1135,11 @@ static int dasd_eckd_read_conf(struct dasd_device *device) 
			break;

		}

		path_data->opm |= lpm;



		if (conf_data != private->conf_data)

			kfree(conf_data);

	}

	}



	return 0;

}
@@ -1090,12 +1172,61 @@ static int verify_fcx_max_data(struct dasd_device *device, __u8 lpm) 
	return 0;

}



static int rebuild_device_uid(struct dasd_device *device,

			      struct path_verification_work_data *data)

{

	struct dasd_eckd_private *private;

	struct dasd_path *path_data;

	__u8 lpm, opm;

	int rc;



	rc = -ENODEV;

	private = (struct dasd_eckd_private *) device->private;

	path_data = &device->path_data;

	opm = device->path_data.opm;



	for (lpm = 0x80; lpm; lpm >>= 1) {

		if (!(lpm & opm))

			continue;

		memset(&data->rcd_buffer, 0, sizeof(data->rcd_buffer));

		memset(&data->cqr, 0, sizeof(data->cqr));

		data->cqr.cpaddr = &data->ccw;

		rc = dasd_eckd_read_conf_immediately(device, &data->cqr,

						     data->rcd_buffer,

						     lpm);



		if (rc) {

			if (rc == -EOPNOTSUPP) /* -EOPNOTSUPP is ok */

				continue;

			DBF_EVENT_DEVID(DBF_WARNING, device->cdev,

					"Read configuration data "

					"returned error %d", rc);

			break;

		}

		memcpy(private->conf_data, data->rcd_buffer,

		       DASD_ECKD_RCD_DATA_SIZE);

		if (dasd_eckd_identify_conf_parts(private)) {

			rc = -ENODEV;

		} else /* first valid path is enough */

			break;

	}



	if (!rc)

		rc = dasd_eckd_generate_uid(device);



	return rc;

}



static void do_path_verification_work(struct work_struct *work)

{

	struct path_verification_work_data *data;

	struct dasd_device *device;

	struct dasd_eckd_private path_private;

	struct dasd_uid *uid;

	__u8 path_rcd_buf[DASD_ECKD_RCD_DATA_SIZE];

	__u8 lpm, opm, npm, ppm, epm;

	unsigned long flags;

	char print_uid[60];

	int rc;



	data = container_of(work, struct path_verification_work_data, worker);
@@ -1112,8 +1243,9 @@ static void do_path_verification_work(struct work_struct *work) 
	ppm = 0;

	epm = 0;

	for (lpm = 0x80; lpm; lpm >>= 1) {

		if (lpm & data->tbvpm) {

			memset(data->rcd_buffer, 0, sizeof(data->rcd_buffer));

		if (!(lpm & data->tbvpm))

			continue;

		memset(&data->rcd_buffer, 0, sizeof(data->rcd_buffer));

		memset(&data->cqr, 0, sizeof(data->cqr));

		data->cqr.cpaddr = &data->ccw;

		rc = dasd_eckd_read_conf_immediately(device, &data->cqr,
@@ -1121,7 +1253,8 @@ static void do_path_verification_work(struct work_struct *work) 
						     lpm);

		if (!rc) {

			switch (dasd_eckd_path_access(data->rcd_buffer,

						     DASD_ECKD_RCD_DATA_SIZE)) {

						      DASD_ECKD_RCD_DATA_SIZE)

				) {

			case 0x02:

				npm |= lpm;

				break;
@@ -1150,9 +1283,71 @@ static void do_path_verification_work(struct work_struct *work) 
			opm &= ~lpm;

			npm &= ~lpm;

			ppm &= ~lpm;

			continue;

		}



		/*

		 * save conf_data for comparison after

		 * rebuild_device_uid may have changed

		 * the original data

		 */

		memcpy(&path_rcd_buf, data->rcd_buffer,

		       DASD_ECKD_RCD_DATA_SIZE);

		path_private.conf_data = (void *) &path_rcd_buf;

		path_private.conf_len = DASD_ECKD_RCD_DATA_SIZE;

		if (dasd_eckd_identify_conf_parts(&path_private)) {

			path_private.conf_data = NULL;

			path_private.conf_len = 0;

			continue;

		}



		/*

		 * compare path UID with device UID only if at least

		 * one valid path is left

		 * in other case the device UID may have changed and

		 * the first working path UID will be used as device UID

		 */

		if (device->path_data.opm &&

		    dasd_eckd_compare_path_uid(device, &path_private)) {

			/*

			 * the comparison was not successful

			 * rebuild the device UID with at least one

			 * known path in case a z/VM hyperswap command

			 * has changed the device

			 *

			 * after this compare again

			 *

			 * if either the rebuild or the recompare fails

			 * the path can not be used

			 */

			if (rebuild_device_uid(device, data) ||

			    dasd_eckd_compare_path_uid(

				    device, &path_private)) {

				uid = &path_private.uid;

				if (strlen(uid->vduit) > 0)

					snprintf(print_uid, sizeof(print_uid),

						 "%s.%s.%04x.%02x.%s",

						 uid->vendor, uid->serial,

						 uid->ssid, uid->real_unit_addr,

						 uid->vduit);

				else

					snprintf(print_uid, sizeof(print_uid),

						 "%s.%s.%04x.%02x",

						 uid->vendor, uid->serial,

						 uid->ssid,

						 uid->real_unit_addr);

				dev_err(&device->cdev->dev,

					"The newly added channel path %02X "

					"will not be used because it leads "

					"to a different device %s\n",

					lpm, print_uid);

				opm &= ~lpm;

				npm &= ~lpm;

				ppm &= ~lpm;

				continue;

			}

		}



		/*

		 * There is a small chance that a path is lost again between

		 * above path verification and the following modification of
@@ -1170,6 +1365,7 @@ static void do_path_verification_work(struct work_struct *work) 
		device->path_data.ppm |= ppm;

		device->path_data.tbvpm |= epm;

		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);

	}



	dasd_put_device(device);

	if (data->isglobal)
@@ -1441,11 +1637,6 @@ dasd_eckd_check_characteristics(struct dasd_device *device) 
			device->default_expires = value;

	}



	/* Generate device unique id */

	rc = dasd_eckd_generate_uid(device);

	if (rc)

		goto out_err1;



	dasd_eckd_get_uid(device, &temp_uid);

	if (temp_uid.type == UA_BASE_DEVICE) {

		block = dasd_alloc_block();