[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: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 6ab2968..763f1bd 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -752,24 +752,13 @@
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 @@
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 @@
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,
@@ -1005,59 +1026,120 @@
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) {
- rc = dasd_eckd_read_conf_lpm(device, &conf_data,
- &conf_len, lpm);
- if (rc && rc != -EOPNOTSUPP) { /* -EOPNOTSUPP is ok */
- DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
- "Read configuration data returned "
- "error %d", rc);
- return rc;
- }
- if (conf_data == NULL) {
- DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
- "No configuration data "
- "retrieved");
- /* no further analysis possible */
- path_data->opm |= lpm;
- continue; /* no error */
- }
- /* save first valid configuration data */
- if (!conf_data_saved) {
- kfree(private->conf_data);
- private->conf_data = conf_data;
- private->conf_len = conf_len;
- if (dasd_eckd_identify_conf_parts(private)) {
- private->conf_data = NULL;
- private->conf_len = 0;
- kfree(conf_data);
- continue;
- }
- conf_data_saved++;
- }
- switch (dasd_eckd_path_access(conf_data, conf_len)) {
- case 0x02:
- path_data->npm |= lpm;
- break;
- case 0x03:
- path_data->ppm |= lpm;
- break;
- }
- path_data->opm |= lpm;
- if (conf_data != private->conf_data)
- kfree(conf_data);
+ if (!(lpm & opm))
+ continue;
+ rc = dasd_eckd_read_conf_lpm(device, &conf_data,
+ &conf_len, lpm);
+ if (rc && rc != -EOPNOTSUPP) { /* -EOPNOTSUPP is ok */
+ DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
+ "Read configuration data returned "
+ "error %d", rc);
+ return rc;
}
+ if (conf_data == NULL) {
+ DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+ "No configuration data "
+ "retrieved");
+ /* no further analysis possible */
+ path_data->opm |= lpm;
+ continue; /* no error */
+ }
+ /* save first valid configuration data */
+ if (!conf_data_saved) {
+ kfree(private->conf_data);
+ private->conf_data = conf_data;
+ private->conf_len = conf_len;
+ if (dasd_eckd_identify_conf_parts(private)) {
+ private->conf_data = NULL;
+ private->conf_len = 0;
+ 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:
+ path_data->npm |= lpm;
+ break;
+ case 0x03:
+ path_data->ppm |= lpm;
+ break;
+ }
+ path_data->opm |= lpm;
+
+ if (conf_data != private->conf_data)
+ kfree(conf_data);
}
+
return 0;
}
@@ -1090,12 +1172,61 @@
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);
@@ -1112,64 +1243,129 @@
ppm = 0;
epm = 0;
for (lpm = 0x80; lpm; lpm >>= 1) {
- if (lpm & data->tbvpm) {
- 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) {
- switch (dasd_eckd_path_access(data->rcd_buffer,
- DASD_ECKD_RCD_DATA_SIZE)) {
- case 0x02:
- npm |= lpm;
- break;
- case 0x03:
- ppm |= lpm;
- break;
- }
- opm |= lpm;
- } else if (rc == -EOPNOTSUPP) {
- DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
- "path verification: No configuration "
- "data retrieved");
- opm |= lpm;
- } else if (rc == -EAGAIN) {
- DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+ 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,
+ data->rcd_buffer,
+ lpm);
+ if (!rc) {
+ switch (dasd_eckd_path_access(data->rcd_buffer,
+ DASD_ECKD_RCD_DATA_SIZE)
+ ) {
+ case 0x02:
+ npm |= lpm;
+ break;
+ case 0x03:
+ ppm |= lpm;
+ break;
+ }
+ opm |= lpm;
+ } else if (rc == -EOPNOTSUPP) {
+ DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+ "path verification: No configuration "
+ "data retrieved");
+ opm |= lpm;
+ } else if (rc == -EAGAIN) {
+ DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
"path verification: device is stopped,"
" try again later");
- epm |= lpm;
- } else {
- dev_warn(&device->cdev->dev,
- "Reading device feature codes failed "
- "(rc=%d) for new path %x\n", rc, lpm);
- continue;
- }
- if (verify_fcx_max_data(device, lpm)) {
+ epm |= lpm;
+ } else {
+ dev_warn(&device->cdev->dev,
+ "Reading device feature codes failed "
+ "(rc=%d) for new path %x\n", rc, lpm);
+ continue;
+ }
+ if (verify_fcx_max_data(device, lpm)) {
+ 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
+ * the device opm mask. We could avoid that race here by using
+ * yet another path mask, but we rather deal with this unlikely
+ * situation in dasd_start_IO.
+ */
+ spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+ if (!device->path_data.opm && opm) {
+ device->path_data.opm = opm;
+ dasd_generic_path_operational(device);
+ } else
+ device->path_data.opm |= opm;
+ device->path_data.npm |= npm;
+ device->path_data.ppm |= ppm;
+ device->path_data.tbvpm |= epm;
+ spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
}
- /*
- * There is a small chance that a path is lost again between
- * above path verification and the following modification of
- * the device opm mask. We could avoid that race here by using
- * yet another path mask, but we rather deal with this unlikely
- * situation in dasd_start_IO.
- */
- spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
- if (!device->path_data.opm && opm) {
- device->path_data.opm = opm;
- dasd_generic_path_operational(device);
- } else
- device->path_data.opm |= opm;
- device->path_data.npm |= npm;
- 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 @@
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();