[S390] dasd: do path verification for paths added at runtime
When a new path is added at runtime, the CIO layer will call the drivers
path_event callback. The DASD device driver uses this callback to trigger
a path verification for the new path. The driver will use only those
paths for I/O, which have been successfully verified.
Signed-off-by: Stefan Weinhuber <wein@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 549443a..a1ebf57 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -90,6 +90,18 @@
} *dasd_reserve_req;
static DEFINE_MUTEX(dasd_reserve_mutex);
+/* definitions for the path verification worker */
+struct path_verification_work_data {
+ struct work_struct worker;
+ struct dasd_device *device;
+ struct dasd_ccw_req cqr;
+ struct ccw1 ccw;
+ __u8 rcd_buffer[DASD_ECKD_RCD_DATA_SIZE];
+ int isglobal;
+ __u8 tbvpm;
+};
+static struct path_verification_work_data *path_verification_worker;
+static DEFINE_MUTEX(dasd_path_verification_mutex);
/* initial attempt at a probe function. this can be simplified once
* the other detection code is gone */
@@ -755,26 +767,27 @@
return -EINVAL;
}
-static struct dasd_ccw_req *dasd_eckd_build_rcd_lpm(struct dasd_device *device,
- void *rcd_buffer,
- struct ciw *ciw, __u8 lpm)
+static void dasd_eckd_fill_rcd_cqr(struct dasd_device *device,
+ struct dasd_ccw_req *cqr,
+ __u8 *rcd_buffer,
+ __u8 lpm)
{
- struct dasd_ccw_req *cqr;
struct ccw1 *ccw;
-
- cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* RCD */, ciw->count,
- device);
-
- if (IS_ERR(cqr)) {
- DBF_DEV_EVENT(DBF_WARNING, device, "%s",
- "Could not allocate RCD request");
- return cqr;
- }
+ /*
+ * buffer has to start with EBCDIC "V1.0" to show
+ * support for virtual device SNEQ
+ */
+ rcd_buffer[0] = 0xE5;
+ rcd_buffer[1] = 0xF1;
+ rcd_buffer[2] = 0x4B;
+ rcd_buffer[3] = 0xF0;
ccw = cqr->cpaddr;
- ccw->cmd_code = ciw->cmd;
+ ccw->cmd_code = DASD_ECKD_CCW_RCD;
+ ccw->flags = 0;
ccw->cda = (__u32)(addr_t)rcd_buffer;
- ccw->count = ciw->count;
+ ccw->count = DASD_ECKD_RCD_DATA_SIZE;
+ cqr->magic = DASD_ECKD_MAGIC;
cqr->startdev = device;
cqr->memdev = device;
@@ -784,7 +797,29 @@
cqr->retries = 256;
cqr->buildclk = get_clock();
cqr->status = DASD_CQR_FILLED;
- return cqr;
+ set_bit(DASD_CQR_VERIFY_PATH, &cqr->flags);
+}
+
+static int dasd_eckd_read_conf_immediately(struct dasd_device *device,
+ struct dasd_ccw_req *cqr,
+ __u8 *rcd_buffer,
+ __u8 lpm)
+{
+ struct ciw *ciw;
+ int rc;
+ /*
+ * sanity check: scan for RCD command in extended SenseID data
+ * some devices do not support RCD
+ */
+ ciw = ccw_device_get_ciw(device->cdev, CIW_TYPE_RCD);
+ if (!ciw || ciw->cmd != DASD_ECKD_CCW_RCD)
+ return -EOPNOTSUPP;
+
+ dasd_eckd_fill_rcd_cqr(device, cqr, rcd_buffer, lpm);
+ clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+ cqr->retries = 5;
+ rc = dasd_sleep_on_immediatly(cqr);
+ return rc;
}
static int dasd_eckd_read_conf_lpm(struct dasd_device *device,
@@ -797,32 +832,29 @@
struct dasd_ccw_req *cqr;
/*
- * scan for RCD command in extended SenseID data
+ * sanity check: scan for RCD command in extended SenseID data
+ * some devices do not support RCD
*/
ciw = ccw_device_get_ciw(device->cdev, CIW_TYPE_RCD);
- if (!ciw || ciw->cmd == 0) {
+ if (!ciw || ciw->cmd != DASD_ECKD_CCW_RCD) {
ret = -EOPNOTSUPP;
goto out_error;
}
- rcd_buf = kzalloc(ciw->count, GFP_KERNEL | GFP_DMA);
+ rcd_buf = kzalloc(DASD_ECKD_RCD_DATA_SIZE, GFP_KERNEL | GFP_DMA);
if (!rcd_buf) {
ret = -ENOMEM;
goto out_error;
}
-
- /*
- * buffer has to start with EBCDIC "V1.0" to show
- * support for virtual device SNEQ
- */
- rcd_buf[0] = 0xE5;
- rcd_buf[1] = 0xF1;
- rcd_buf[2] = 0x4B;
- rcd_buf[3] = 0xF0;
- cqr = dasd_eckd_build_rcd_lpm(device, rcd_buf, ciw, lpm);
+ cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* RCD */,
+ 0, /* use rcd_buf as data ara */
+ device);
if (IS_ERR(cqr)) {
- ret = PTR_ERR(cqr);
+ DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+ "Could not allocate RCD request");
+ ret = -ENOMEM;
goto out_error;
}
+ dasd_eckd_fill_rcd_cqr(device, cqr, rcd_buf, lpm);
ret = dasd_sleep_on(cqr);
/*
* on success we update the user input parms
@@ -831,7 +863,7 @@
if (ret)
goto out_error;
- *rcd_buffer_size = ciw->count;
+ *rcd_buffer_size = DASD_ECKD_RCD_DATA_SIZE;
*rcd_buffer = rcd_buf;
return 0;
out_error:
@@ -901,18 +933,18 @@
void *conf_data;
int conf_len, conf_data_saved;
int rc;
- __u8 lpm;
+ __u8 lpm, opm;
struct dasd_eckd_private *private;
- struct dasd_eckd_path *path_data;
+ struct dasd_path *path_data;
private = (struct dasd_eckd_private *) device->private;
- path_data = (struct dasd_eckd_path *) &private->path_data;
- path_data->opm = ccw_device_get_path_mask(device->cdev);
+ 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 & path_data->opm){
+ if (lpm & opm) {
rc = dasd_eckd_read_conf_lpm(device, &conf_data,
&conf_len, lpm);
if (rc && rc != -EOPNOTSUPP) { /* -EOPNOTSUPP is ok */
@@ -925,6 +957,8 @@
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 */
@@ -948,6 +982,7 @@
path_data->ppm |= lpm;
break;
}
+ path_data->opm |= lpm;
if (conf_data != private->conf_data)
kfree(conf_data);
}
@@ -955,6 +990,140 @@
return 0;
}
+static int verify_fcx_max_data(struct dasd_device *device, __u8 lpm)
+{
+ struct dasd_eckd_private *private;
+ int mdc;
+ u32 fcx_max_data;
+
+ private = (struct dasd_eckd_private *) device->private;
+ if (private->fcx_max_data) {
+ mdc = ccw_device_get_mdc(device->cdev, lpm);
+ if ((mdc < 0)) {
+ dev_warn(&device->cdev->dev,
+ "Detecting the maximum data size for zHPF "
+ "requests failed (rc=%d) for a new path %x\n",
+ mdc, lpm);
+ return mdc;
+ }
+ fcx_max_data = mdc * FCX_MAX_DATA_FACTOR;
+ if (fcx_max_data < private->fcx_max_data) {
+ dev_warn(&device->cdev->dev,
+ "The maximum data size for zHPF requests %u "
+ "on a new path %x is below the active maximum "
+ "%u\n", fcx_max_data, lpm,
+ private->fcx_max_data);
+ return -EACCES;
+ }
+ }
+ return 0;
+}
+
+static void do_path_verification_work(struct work_struct *work)
+{
+ struct path_verification_work_data *data;
+ struct dasd_device *device;
+ __u8 lpm, opm, npm, ppm, epm;
+ unsigned long flags;
+ int rc;
+
+ data = container_of(work, struct path_verification_work_data, worker);
+ device = data->device;
+
+ opm = 0;
+ npm = 0;
+ 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",
+ "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)) {
+ opm &= ~lpm;
+ npm &= ~lpm;
+ ppm &= ~lpm;
+ }
+ }
+ }
+ /*
+ * 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)
+ mutex_unlock(&dasd_path_verification_mutex);
+ else
+ kfree(data);
+}
+
+static int dasd_eckd_verify_path(struct dasd_device *device, __u8 lpm)
+{
+ struct path_verification_work_data *data;
+
+ data = kmalloc(sizeof(*data), GFP_ATOMIC | GFP_DMA);
+ if (!data) {
+ if (mutex_trylock(&dasd_path_verification_mutex)) {
+ data = path_verification_worker;
+ data->isglobal = 1;
+ } else
+ return -ENOMEM;
+ } else {
+ memset(data, 0, sizeof(*data));
+ data->isglobal = 0;
+ }
+ INIT_WORK(&data->worker, do_path_verification_work);
+ dasd_get_device(device);
+ data->device = device;
+ data->tbvpm = lpm;
+ schedule_work(&data->worker);
+ return 0;
+}
+
static int dasd_eckd_read_features(struct dasd_device *device)
{
struct dasd_psf_prssd_data *prssdp;
@@ -1749,6 +1918,7 @@
if (cqr->block && (cqr->startdev != cqr->block->base)) {
dasd_eckd_reset_ccw_to_base_io(cqr);
cqr->startdev = cqr->block->base;
+ cqr->lpm = cqr->block->base->path_data.opm;
}
};
@@ -2017,7 +2187,7 @@
cqr->memdev = startdev;
cqr->block = block;
cqr->expires = startdev->default_expires * HZ; /* default 5 minutes */
- cqr->lpm = private->path_data.ppm;
+ cqr->lpm = startdev->path_data.ppm;
cqr->retries = 256;
cqr->buildclk = get_clock();
cqr->status = DASD_CQR_FILLED;
@@ -2194,7 +2364,7 @@
cqr->memdev = startdev;
cqr->block = block;
cqr->expires = startdev->default_expires * HZ; /* default 5 minutes */
- cqr->lpm = private->path_data.ppm;
+ cqr->lpm = startdev->path_data.ppm;
cqr->retries = 256;
cqr->buildclk = get_clock();
cqr->status = DASD_CQR_FILLED;
@@ -2484,7 +2654,7 @@
cqr->memdev = startdev;
cqr->block = block;
cqr->expires = startdev->default_expires * HZ; /* default 5 minutes */
- cqr->lpm = private->path_data.ppm;
+ cqr->lpm = startdev->path_data.ppm;
cqr->retries = 256;
cqr->buildclk = get_clock();
cqr->status = DASD_CQR_FILLED;
@@ -3624,6 +3794,7 @@
.set_offline = dasd_generic_set_offline,
.set_online = dasd_eckd_set_online,
.notify = dasd_generic_notify,
+ .path_event = dasd_generic_path_event,
.freeze = dasd_generic_pm_freeze,
.thaw = dasd_generic_restore_device,
.restore = dasd_generic_restore_device,
@@ -3651,6 +3822,7 @@
.check_device = dasd_eckd_check_characteristics,
.uncheck_device = dasd_eckd_uncheck_device,
.do_analysis = dasd_eckd_do_analysis,
+ .verify_path = dasd_eckd_verify_path,
.ready_to_online = dasd_eckd_ready_to_online,
.online_to_ready = dasd_eckd_online_to_ready,
.fill_geometry = dasd_eckd_fill_geometry,
@@ -3683,11 +3855,19 @@
GFP_KERNEL | GFP_DMA);
if (!dasd_reserve_req)
return -ENOMEM;
+ path_verification_worker = kmalloc(sizeof(*path_verification_worker),
+ GFP_KERNEL | GFP_DMA);
+ if (!path_verification_worker) {
+ kfree(dasd_reserve_req);
+ return -ENOMEM;
+ }
ret = ccw_driver_register(&dasd_eckd_driver);
if (!ret)
wait_for_device_probe();
- else
+ else {
+ kfree(path_verification_worker);
kfree(dasd_reserve_req);
+ }
return ret;
}
@@ -3695,6 +3875,7 @@
dasd_eckd_cleanup(void)
{
ccw_driver_unregister(&dasd_eckd_driver);
+ kfree(path_verification_worker);
kfree(dasd_reserve_req);
}