From b206181d636d416fde48c7f493d7ac5d935b57e3 Mon Sep 17 00:00:00 2001 From: Stefan Haberland Date: Tue, 27 Dec 2011 11:27:27 +0100 Subject: [PATCH] [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 Signed-off-by: Martin Schwidefsky --- drivers/s390/block/dasd_eckd.c | 409 ++++++++++++++++++++++++--------- 1 file changed, 300 insertions(+), 109 deletions(-) diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c index 6ab29680586a..763f1bd9605a 100644 --- a/drivers/s390/block/dasd_eckd.c +++ b/drivers/s390/block/dasd_eckd.c @@ -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, @@ -1005,59 +1026,120 @@ 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) { - 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 */ + 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; } - /* 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++; + /* + * 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; } - switch (dasd_eckd_path_access(conf_data, conf_len)) { - case 0x02: - path_data->npm |= lpm; - break; - case 0x03: - path_data->ppm |= lpm; - break; + + 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_data->opm |= lpm; - if (conf_data != private->conf_data) - kfree(conf_data); + + 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 @@ 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); @@ -1112,64 +1243,129 @@ 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)); - 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 @@ 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(); -- 2.39.5