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[S390] dasd: do path verification for paths added at runtime
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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>
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Stefan Weinhuber authored and Martin Schwidefsky committed Jan 5, 2011
1 parent ef19298 commit a4d26c6
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Showing 9 changed files with 418 additions and 100 deletions.
202 changes: 158 additions & 44 deletions drivers/s390/block/dasd.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -913,6 +913,11 @@ int dasd_start_IO(struct dasd_ccw_req *cqr)
cqr->startclk = get_clock();
cqr->starttime = jiffies;
cqr->retries--;
if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
cqr->lpm &= device->path_data.opm;
if (!cqr->lpm)
cqr->lpm = device->path_data.opm;
}
if (cqr->cpmode == 1) {
rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
(long) cqr, cqr->lpm);
Expand All @@ -925,35 +930,53 @@ int dasd_start_IO(struct dasd_ccw_req *cqr)
cqr->status = DASD_CQR_IN_IO;
break;
case -EBUSY:
DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: device busy, retry later");
break;
case -ETIMEDOUT:
DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: request timeout, retry later");
break;
case -EACCES:
/* -EACCES indicates that the request used only a
* subset of the available pathes and all these
* pathes are gone.
* Do a retry with all available pathes.
/* -EACCES indicates that the request used only a subset of the
* available paths and all these paths are gone. If the lpm of
* this request was only a subset of the opm (e.g. the ppm) then
* we just do a retry with all available paths.
* If we already use the full opm, something is amiss, and we
* need a full path verification.
*/
cqr->lpm = LPM_ANYPATH;
DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
"start_IO: selected pathes gone,"
" retry on all pathes");
if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
DBF_DEV_EVENT(DBF_WARNING, device,
"start_IO: selected paths gone (%x)",
cqr->lpm);
} else if (cqr->lpm != device->path_data.opm) {
cqr->lpm = device->path_data.opm;
DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
"start_IO: selected paths gone,"
" retry on all paths");
} else {
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: all paths in opm gone,"
" do path verification");
dasd_generic_last_path_gone(device);
device->path_data.opm = 0;
device->path_data.ppm = 0;
device->path_data.npm = 0;
device->path_data.tbvpm =
ccw_device_get_path_mask(device->cdev);
}
break;
case -ENODEV:
DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: -ENODEV device gone, retry");
break;
case -EIO:
DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: -EIO device gone, retry");
break;
case -EINVAL:
/* most likely caused in power management context */
DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: -EINVAL device currently "
"not accessible");
break;
Expand Down Expand Up @@ -1175,12 +1198,13 @@ void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
*/
if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
cqr->retries > 0) {
if (cqr->lpm == LPM_ANYPATH)
if (cqr->lpm == device->path_data.opm)
DBF_DEV_EVENT(DBF_DEBUG, device,
"default ERP in fastpath "
"(%i retries left)",
cqr->retries);
cqr->lpm = LPM_ANYPATH;
if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
cqr->lpm = device->path_data.opm;
cqr->status = DASD_CQR_QUEUED;
next = cqr;
} else
Expand Down Expand Up @@ -1364,8 +1388,14 @@ static void __dasd_device_start_head(struct dasd_device *device)
cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
if (cqr->status != DASD_CQR_QUEUED)
return;
/* when device is stopped, return request to previous layer */
if (device->stopped) {
/* when device is stopped, return request to previous layer
* exception: only the disconnect or unresumed bits are set and the
* cqr is a path verification request
*/
if (device->stopped &&
!(!(device->stopped & ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
&& test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))) {
cqr->intrc = -EAGAIN;
cqr->status = DASD_CQR_CLEARED;
dasd_schedule_device_bh(device);
return;
Expand All @@ -1381,6 +1411,23 @@ static void __dasd_device_start_head(struct dasd_device *device)
dasd_device_set_timer(device, 50);
}

static void __dasd_device_check_path_events(struct dasd_device *device)
{
int rc;

if (device->path_data.tbvpm) {
if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
DASD_UNRESUMED_PM))
return;
rc = device->discipline->verify_path(
device, device->path_data.tbvpm);
if (rc)
dasd_device_set_timer(device, 50);
else
device->path_data.tbvpm = 0;
}
};

/*
* Go through all request on the dasd_device request queue,
* terminate them on the cdev if necessary, and return them to the
Expand Down Expand Up @@ -1455,6 +1502,7 @@ static void dasd_device_tasklet(struct dasd_device *device)
__dasd_device_check_expire(device);
/* find final requests on ccw queue */
__dasd_device_process_ccw_queue(device, &final_queue);
__dasd_device_check_path_events(device);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
/* Now call the callback function of requests with final status */
__dasd_device_process_final_queue(device, &final_queue);
Expand Down Expand Up @@ -2586,10 +2634,53 @@ int dasd_generic_set_offline(struct ccw_device *cdev)
return 0;
}

int dasd_generic_last_path_gone(struct dasd_device *device)
{
struct dasd_ccw_req *cqr;

dev_warn(&device->cdev->dev, "No operational channel path is left "
"for the device\n");
DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
/* First of all call extended error reporting. */
dasd_eer_write(device, NULL, DASD_EER_NOPATH);

if (device->state < DASD_STATE_BASIC)
return 0;
/* Device is active. We want to keep it. */
list_for_each_entry(cqr, &device->ccw_queue, devlist)
if ((cqr->status == DASD_CQR_IN_IO) ||
(cqr->status == DASD_CQR_CLEAR_PENDING)) {
cqr->status = DASD_CQR_QUEUED;
cqr->retries++;
}
dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
dasd_device_clear_timer(device);
dasd_schedule_device_bh(device);
return 1;
}
EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);

int dasd_generic_path_operational(struct dasd_device *device)
{
dev_info(&device->cdev->dev, "A channel path to the device has become "
"operational\n");
DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
if (device->stopped & DASD_UNRESUMED_PM) {
dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
dasd_restore_device(device);
return 1;
}
dasd_schedule_device_bh(device);
if (device->block)
dasd_schedule_block_bh(device->block);
return 1;
}
EXPORT_SYMBOL_GPL(dasd_generic_path_operational);

int dasd_generic_notify(struct ccw_device *cdev, int event)
{
struct dasd_device *device;
struct dasd_ccw_req *cqr;
int ret;

device = dasd_device_from_cdev_locked(cdev);
Expand All @@ -2600,41 +2691,64 @@ int dasd_generic_notify(struct ccw_device *cdev, int event)
case CIO_GONE:
case CIO_BOXED:
case CIO_NO_PATH:
/* First of all call extended error reporting. */
dasd_eer_write(device, NULL, DASD_EER_NOPATH);

if (device->state < DASD_STATE_BASIC)
break;
/* Device is active. We want to keep it. */
list_for_each_entry(cqr, &device->ccw_queue, devlist)
if (cqr->status == DASD_CQR_IN_IO) {
cqr->status = DASD_CQR_QUEUED;
cqr->retries++;
}
dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
dasd_device_clear_timer(device);
dasd_schedule_device_bh(device);
ret = 1;
device->path_data.opm = 0;
device->path_data.ppm = 0;
device->path_data.npm = 0;
ret = dasd_generic_last_path_gone(device);
break;
case CIO_OPER:
/* FIXME: add a sanity check. */
dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
if (device->stopped & DASD_UNRESUMED_PM) {
dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
dasd_restore_device(device);
ret = 1;
break;
}
dasd_schedule_device_bh(device);
if (device->block)
dasd_schedule_block_bh(device->block);
ret = 1;
if (device->path_data.opm)
ret = dasd_generic_path_operational(device);
break;
}
dasd_put_device(device);
return ret;
}

void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
{
int chp;
__u8 oldopm, eventlpm;
struct dasd_device *device;

device = dasd_device_from_cdev_locked(cdev);
if (IS_ERR(device))
return;
for (chp = 0; chp < 8; chp++) {
eventlpm = 0x80 >> chp;
if (path_event[chp] & PE_PATH_GONE) {
oldopm = device->path_data.opm;
device->path_data.opm &= ~eventlpm;
device->path_data.ppm &= ~eventlpm;
device->path_data.npm &= ~eventlpm;
if (oldopm && !device->path_data.opm)
dasd_generic_last_path_gone(device);
}
if (path_event[chp] & PE_PATH_AVAILABLE) {
device->path_data.opm &= ~eventlpm;
device->path_data.ppm &= ~eventlpm;
device->path_data.npm &= ~eventlpm;
device->path_data.tbvpm |= eventlpm;
dasd_schedule_device_bh(device);
}
}
dasd_put_device(device);
}
EXPORT_SYMBOL_GPL(dasd_generic_path_event);

int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
{
if (!device->path_data.opm && lpm) {
device->path_data.opm = lpm;
dasd_generic_path_operational(device);
} else
device->path_data.opm |= lpm;
return 0;
}
EXPORT_SYMBOL_GPL(dasd_generic_verify_path);


int dasd_generic_pm_freeze(struct ccw_device *cdev)
{
struct dasd_ccw_req *cqr, *n;
Expand Down
16 changes: 8 additions & 8 deletions drivers/s390/block/dasd_3990_erp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -152,9 +152,9 @@ dasd_3990_erp_alternate_path(struct dasd_ccw_req * erp)
spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
opm = ccw_device_get_path_mask(device->cdev);
spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
//FIXME: start with get_opm ?
if (erp->lpm == 0)
erp->lpm = LPM_ANYPATH & ~(erp->irb.esw.esw0.sublog.lpum);
erp->lpm = device->path_data.opm &
~(erp->irb.esw.esw0.sublog.lpum);
else
erp->lpm &= ~(erp->irb.esw.esw0.sublog.lpum);

Expand Down Expand Up @@ -270,10 +270,11 @@ static struct dasd_ccw_req *dasd_3990_erp_action_1(struct dasd_ccw_req *erp)
{
erp->function = dasd_3990_erp_action_1;
dasd_3990_erp_alternate_path(erp);
if (erp->status == DASD_CQR_FAILED) {
if (erp->status == DASD_CQR_FAILED &&
!test_bit(DASD_CQR_VERIFY_PATH, &erp->flags)) {
erp->status = DASD_CQR_FILLED;
erp->retries = 10;
erp->lpm = LPM_ANYPATH;
erp->lpm = erp->startdev->path_data.opm;
erp->function = dasd_3990_erp_action_1_sec;
}
return erp;
Expand Down Expand Up @@ -1907,15 +1908,14 @@ dasd_3990_erp_compound_retry(struct dasd_ccw_req * erp, char *sense)
static void
dasd_3990_erp_compound_path(struct dasd_ccw_req * erp, char *sense)
{

if (sense[25] & DASD_SENSE_BIT_3) {
dasd_3990_erp_alternate_path(erp);

if (erp->status == DASD_CQR_FAILED) {
if (erp->status == DASD_CQR_FAILED &&
!test_bit(DASD_CQR_VERIFY_PATH, &erp->flags)) {
/* reset the lpm and the status to be able to
* try further actions. */

erp->lpm = 0;
erp->lpm = erp->startdev->path_data.opm;
erp->status = DASD_CQR_NEED_ERP;
}
}
Expand Down
1 change: 1 addition & 0 deletions drivers/s390/block/dasd_devmap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -639,6 +639,7 @@ dasd_put_device_wake(struct dasd_device *device)
{
wake_up(&dasd_delete_wq);
}
EXPORT_SYMBOL_GPL(dasd_put_device_wake);

/*
* Return dasd_device structure associated with cdev.
Expand Down
1 change: 1 addition & 0 deletions drivers/s390/block/dasd_diag.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -619,6 +619,7 @@ static struct dasd_discipline dasd_diag_discipline = {
.ebcname = "DIAG",
.max_blocks = DIAG_MAX_BLOCKS,
.check_device = dasd_diag_check_device,
.verify_path = dasd_generic_verify_path,
.fill_geometry = dasd_diag_fill_geometry,
.start_IO = dasd_start_diag,
.term_IO = dasd_diag_term_IO,
Expand Down
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