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[S390] dasd: improve error recovery for internal I/O

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Most of the error conditions reported by a FICON storage server
indicate situations which can be recovered. Sometimes the host just
needs to retry an I/O request, but sometimes the recovery
is more complex and requires the device driver to wait, choose
a different path, etc.

The DASD device driver has a fully featured error recovery
for normal block layer I/O, but not for internal I/O request which
are for example used during the device bring up.
This can lead to situations where the IPL of a system fails because
DASD devices are not properly recognized.
This patch will extend the internal I/O handling to use the existing
error recovery procedures.

Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Stefan Weinhuber
2009-12-07 12:51:51 +01:00
committed by Martin Schwidefsky
parent 626350b63e
commit eb6e199bef
6 changed files with 260 additions and 101 deletions
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drivers/s390/block/dasd_eckd.c
+55 -17
View File
@@ -77,6 +77,11 @@ MODULE_DEVICE_TABLE(ccw, dasd_eckd_ids);
static struct ccw_driver dasd_eckd_driver; /* see below */
#define INIT_CQR_OK 0
#define INIT_CQR_UNFORMATTED 1
#define INIT_CQR_ERROR 2
/* initial attempt at a probe function. this can be simplified once
* the other detection code is gone */
static int
@@ -749,8 +754,7 @@ static struct dasd_ccw_req *dasd_eckd_build_rcd_lpm(struct dasd_device *device,
cqr->block = NULL;
cqr->expires = 10*HZ;
cqr->lpm = lpm;
clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
cqr->retries = 2;
cqr->retries = 256;
cqr->buildclk = get_clock();
cqr->status = DASD_CQR_FILLED;
return cqr;
@@ -949,8 +953,7 @@ static int dasd_eckd_read_features(struct dasd_device *device)
cqr->startdev = device;
cqr->memdev = device;
cqr->block = NULL;
clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
cqr->retries = 5;
cqr->retries = 256;
cqr->expires = 10 * HZ;
/* Prepare for Read Subsystem Data */
@@ -1025,6 +1028,7 @@ static struct dasd_ccw_req *dasd_eckd_build_psf_ssc(struct dasd_device *device,
cqr->startdev = device;
cqr->memdev = device;
cqr->block = NULL;
cqr->retries = 256;
cqr->expires = 10*HZ;
cqr->buildclk = get_clock();
cqr->status = DASD_CQR_FILLED;
@@ -1068,6 +1072,7 @@ static int dasd_eckd_validate_server(struct dasd_device *device)
else
enable_pav = 1;
rc = dasd_eckd_psf_ssc(device, enable_pav);
/* may be requested feature is not available on server,
* therefore just report error and go ahead */
private = (struct dasd_eckd_private *) device->private;
@@ -1265,12 +1270,29 @@ dasd_eckd_analysis_ccw(struct dasd_device *device)
cqr->block = NULL;
cqr->startdev = device;
cqr->memdev = device;
cqr->retries = 0;
cqr->retries = 255;
cqr->buildclk = get_clock();
cqr->status = DASD_CQR_FILLED;
return cqr;
}
/* differentiate between 'no record found' and any other error */
static int dasd_eckd_analysis_evaluation(struct dasd_ccw_req *init_cqr)
{
char *sense;
if (init_cqr->status == DASD_CQR_DONE)
return INIT_CQR_OK;
else if (init_cqr->status == DASD_CQR_NEED_ERP ||
init_cqr->status == DASD_CQR_FAILED) {
sense = dasd_get_sense(&init_cqr->irb);
if (sense && (sense[1] & SNS1_NO_REC_FOUND))
return INIT_CQR_UNFORMATTED;
else
return INIT_CQR_ERROR;
} else
return INIT_CQR_ERROR;
}
/*
* This is the callback function for the init_analysis cqr. It saves
* the status of the initial analysis ccw before it frees it and kicks
@@ -1278,21 +1300,20 @@ dasd_eckd_analysis_ccw(struct dasd_device *device)
* dasd_eckd_do_analysis again (if the devices has not been marked
* for deletion in the meantime).
*/
static void
dasd_eckd_analysis_callback(struct dasd_ccw_req *init_cqr, void *data)
static void dasd_eckd_analysis_callback(struct dasd_ccw_req *init_cqr,
void *data)
{
struct dasd_eckd_private *private;
struct dasd_device *device;
device = init_cqr->startdev;
private = (struct dasd_eckd_private *) device->private;
private->init_cqr_status = init_cqr->status;
private->init_cqr_status = dasd_eckd_analysis_evaluation(init_cqr);
dasd_sfree_request(init_cqr, device);
dasd_kick_device(device);
}
static int
dasd_eckd_start_analysis(struct dasd_block *block)
static int dasd_eckd_start_analysis(struct dasd_block *block)
{
struct dasd_eckd_private *private;
struct dasd_ccw_req *init_cqr;
@@ -1304,27 +1325,44 @@ dasd_eckd_start_analysis(struct dasd_block *block)
init_cqr->callback = dasd_eckd_analysis_callback;
init_cqr->callback_data = NULL;
init_cqr->expires = 5*HZ;
/* first try without ERP, so we can later handle unformatted
* devices as special case
*/
clear_bit(DASD_CQR_FLAGS_USE_ERP, &init_cqr->flags);
init_cqr->retries = 0;
dasd_add_request_head(init_cqr);
return -EAGAIN;
}
static int
dasd_eckd_end_analysis(struct dasd_block *block)
static int dasd_eckd_end_analysis(struct dasd_block *block)
{
struct dasd_device *device;
struct dasd_eckd_private *private;
struct eckd_count *count_area;
unsigned int sb, blk_per_trk;
int status, i;
struct dasd_ccw_req *init_cqr;
device = block->base;
private = (struct dasd_eckd_private *) device->private;
status = private->init_cqr_status;
private->init_cqr_status = -1;
if (status != DASD_CQR_DONE) {
dev_warn(&device->cdev->dev,
"The DASD is not formatted\n");
if (status == INIT_CQR_ERROR) {
/* try again, this time with full ERP */
init_cqr = dasd_eckd_analysis_ccw(device);
dasd_sleep_on(init_cqr);
status = dasd_eckd_analysis_evaluation(init_cqr);
dasd_sfree_request(init_cqr, device);
}
if (status == INIT_CQR_UNFORMATTED) {
dev_warn(&device->cdev->dev, "The DASD is not formatted\n");
return -EMEDIUMTYPE;
} else if (status == INIT_CQR_ERROR) {
dev_err(&device->cdev->dev,
"Detecting the DASD disk layout failed because "
"of an I/O error\n");
return -EIO;
}
private->uses_cdl = 1;
@@ -1616,8 +1654,7 @@ dasd_eckd_format_device(struct dasd_device * device,
}
fcp->startdev = device;
fcp->memdev = device;
clear_bit(DASD_CQR_FLAGS_USE_ERP, &fcp->flags);
fcp->retries = 5; /* set retry counter to enable default ERP */
fcp->retries = 256;
fcp->buildclk = get_clock();
fcp->status = DASD_CQR_FILLED;
return fcp;
@@ -2699,6 +2736,7 @@ dasd_eckd_performance(struct dasd_device *device, void __user *argp)
cqr->startdev = device;
cqr->memdev = device;
cqr->retries = 0;
clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
cqr->expires = 10 * HZ;
/* Prepare for Read Subsystem Data */