[PATCH] s390 (5/7): tape driver.

From: Martin Schwidefsky
Date: Fri Mar 26 2004 - 13:33:50 EST

s390 tape driver changes:
- Prevent offline while device is in use.
- Do not use bus_id string in debug feature messages.
- Check for IS_ERR(irb) error conditions in interrupt handler.
- Fix removing tape discipline modules.

diffstat:
drivers/s390/char/tape.h | 5 -
drivers/s390/char/tape_34xx.c | 24 ++---
drivers/s390/char/tape_block.c | 7 +
drivers/s390/char/tape_core.c | 196 +++++++++++++++++++++++++++++++++--------
drivers/s390/char/tape_std.c | 22 +++-
5 files changed, 198 insertions(+), 56 deletions(-)

diff -urN linux-2.6/drivers/s390/char/tape.h linux-2.6-s390/drivers/s390/char/tape.h
--- linux-2.6/drivers/s390/char/tape.h Fri Mar 26 18:24:55 2004
+++ linux-2.6-s390/drivers/s390/char/tape.h Fri Mar 26 18:25:58 2004
@@ -198,6 +198,7 @@
/* entry in tape_device_list */
struct list_head node;

+ int cdev_id;
struct ccw_device * cdev;
struct tape_class_device * nt;
struct tape_class_device * rt;
@@ -263,8 +264,8 @@
extern int tape_mtop(struct tape_device *, int, int);
extern void tape_state_set(struct tape_device *, enum tape_state);

-extern int tape_enable_device(struct tape_device *, struct tape_discipline *);
-extern void tape_disable_device(struct tape_device *device);
+extern int tape_generic_online(struct tape_device *, struct tape_discipline *);
+extern int tape_generic_offline(struct tape_device *device);

/* Externals from tape_devmap.c */
extern int tape_generic_probe(struct ccw_device *);
diff -urN linux-2.6/drivers/s390/char/tape_34xx.c linux-2.6-s390/drivers/s390/char/tape_34xx.c
--- linux-2.6/drivers/s390/char/tape_34xx.c Thu Mar 11 03:55:25 2004
+++ linux-2.6-s390/drivers/s390/char/tape_34xx.c Fri Mar 26 18:25:58 2004
@@ -202,8 +202,7 @@
tape_34xx_delete_sbid_from(device, 0);
tape_34xx_schedule_work(device, TO_MSEN);
} else {
- DBF_EVENT(3, "unsol.irq! dev end: %s\n",
- device->cdev->dev.bus_id);
+ DBF_EVENT(3, "unsol.irq! dev end: %08x\n", device->cdev_id);
PRINT_WARN("Unsolicited IRQ (Device End) caught.\n");
tape_dump_sense(device, NULL, irb);
}
@@ -1314,17 +1313,18 @@
};

static int
-tape_34xx_enable(struct ccw_device *cdev)
+tape_34xx_online(struct ccw_device *cdev)
{
- return tape_enable_device(cdev->dev.driver_data,
- &tape_discipline_34xx);
+ return tape_generic_online(
+ cdev->dev.driver_data,
+ &tape_discipline_34xx
+ );
}

static int
-tape_34xx_disable(struct ccw_device *cdev)
+tape_34xx_offline(struct ccw_device *cdev)
{
- tape_disable_device(cdev->dev.driver_data);
- return 0;
+ return tape_generic_offline(cdev->dev.driver_data);
}

static struct ccw_driver tape_34xx_driver = {
@@ -1333,8 +1333,8 @@
.ids = tape_34xx_ids,
.probe = tape_generic_probe,
.remove = tape_generic_remove,
- .set_online = tape_34xx_enable,
- .set_offline = tape_34xx_disable,
+ .set_online = tape_34xx_online,
+ .set_offline = tape_34xx_offline,
};

static int
@@ -1342,7 +1342,7 @@
{
int rc;

- DBF_EVENT(3, "34xx init: $Revision: 1.18 $\n");
+ DBF_EVENT(3, "34xx init: $Revision: 1.19 $\n");
/* Register driver for 3480/3490 tapes. */
rc = ccw_driver_register(&tape_34xx_driver);
if (rc)
@@ -1361,7 +1361,7 @@
MODULE_DEVICE_TABLE(ccw, tape_34xx_ids);
MODULE_AUTHOR("(C) 2001-2002 IBM Deutschland Entwicklung GmbH");
MODULE_DESCRIPTION("Linux on zSeries channel attached 3480 tape "
- "device driver ($Revision: 1.18 $)");
+ "device driver ($Revision: 1.19 $)");
MODULE_LICENSE("GPL");

module_init(tape_34xx_init);
diff -urN linux-2.6/drivers/s390/char/tape_block.c linux-2.6-s390/drivers/s390/char/tape_block.c
--- linux-2.6/drivers/s390/char/tape_block.c Thu Mar 11 03:55:37 2004
+++ linux-2.6-s390/drivers/s390/char/tape_block.c Fri Mar 26 18:25:58 2004
@@ -274,12 +274,19 @@
flush_scheduled_work();
device->blk_data.requeue_task.data = tape_put_device(device);

+ if (!device->blk_data.disk) {
+ PRINT_ERR("(%s): No gendisk to clean up!\n",
+ device->cdev->dev.bus_id);
+ goto cleanup_queue;
+ }
+
del_gendisk(device->blk_data.disk);
device->blk_data.disk->private_data =
tape_put_device(device->blk_data.disk->private_data);
put_disk(device->blk_data.disk);

device->blk_data.disk = NULL;
+cleanup_queue:
device->blk_data.request_queue->queuedata = tape_put_device(device);

blk_cleanup_queue(device->blk_data.request_queue);
diff -urN linux-2.6/drivers/s390/char/tape_core.c linux-2.6-s390/drivers/s390/char/tape_core.c
--- linux-2.6/drivers/s390/char/tape_core.c Thu Mar 11 03:55:24 2004
+++ linux-2.6-s390/drivers/s390/char/tape_core.c Fri Mar 26 18:25:58 2004
@@ -69,6 +69,34 @@
[TO_UNASSIGN] = "UAS"
};

+static inline int
+busid_to_int(char *bus_id)
+{
+ int dec;
+ int d;
+ char * s;
+
+ for(s = bus_id, d = 0; *s != '\0' && *s != '.'; s++)
+ d = (d * 10) + (*s - '0');
+ dec = d;
+ for(s++, d = 0; *s != '\0' && *s != '.'; s++)
+ d = (d * 10) + (*s - '0');
+ dec = (dec << 8) + d;
+
+ for(s++; *s != '\0'; s++) {
+ if (*s >= '0' && *s <= '9') {
+ d = *s - '0';
+ } else if (*s >= 'a' && *s <= 'f') {
+ d = *s - 'a' + 10;
+ } else {
+ d = *s - 'A' + 10;
+ }
+ dec = (dec << 4) + d;
+ }
+
+ return dec;
+}
+
/*
* Some channel attached tape specific attributes.
*
@@ -296,10 +324,15 @@
}

/*
- * Enable tape device
+ * Set a device online.
+ *
+ * This function is called by the common I/O layer to move a device from the
+ * detected but offline into the online state.
+ * If we return an error (RC < 0) the device remains in the offline state. This
+ * can happen if the device is assigned somewhere else, for example.
*/
int
-tape_enable_device(struct tape_device *device,
+tape_generic_online(struct tape_device *device,
struct tape_discipline *discipline)
{
int rc;
@@ -328,6 +361,9 @@
goto out_char;

tape_state_set(device, TS_UNUSED);
+
+ DBF_LH(3, "(%08x): Drive set online\n", device->cdev_id);
+
return 0;

out_char:
@@ -342,37 +378,49 @@
}

/*
- * Disable tape device. Check if there is a running request and
- * terminate it. Post all queued requests with -EIO.
+ * Set device offline.
+ *
+ * Called by the common I/O layer if the drive should set offline on user
+ * request. We may prevent this by returning an error.
+ * Manual offline is only allowed while the drive is not in use.
*/
-void
-tape_disable_device(struct tape_device *device)
+int
+tape_generic_offline(struct tape_device *device)
{
- struct list_head *l, *n;
- struct tape_request *request;
+ if (!device) {
+ PRINT_ERR("tape_generic_offline: no such device\n");
+ return -ENODEV;
+ }
+
+ DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
+ device->cdev_id, device);

spin_lock_irq(get_ccwdev_lock(device->cdev));
- /* Post remaining requests with -EIO */
- list_for_each_safe(l, n, &device->req_queue) {
- request = list_entry(l, struct tape_request, list);
- if (request->status == TAPE_REQUEST_IN_IO)
- __tape_halt_io(device, request);
- list_del(&request->list);
- /* Decrease ref_count for removed request. */
- request->device = tape_put_device(device);
- request->rc = -EIO;
- if (request->callback != NULL)
- request->callback(request, request->callback_data);
+ switch (device->tape_state) {
+ case TS_INIT:
+ case TS_NOT_OPER:
+ break;
+ case TS_UNUSED:
+ tapeblock_cleanup_device(device);
+ tapechar_cleanup_device(device);
+ device->discipline->cleanup_device(device);
+ tape_remove_minor(device);
+ default:
+ DBF_EVENT(3, "(%08x): Set offline failed "
+ "- drive in use.\n",
+ device->cdev_id);
+ PRINT_WARN("(%s): Set offline failed "
+ "- drive in use.\n",
+ device->cdev->dev.bus_id);
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+ return -EBUSY;
}
spin_unlock_irq(get_ccwdev_lock(device->cdev));

- tapeblock_cleanup_device(device);
- tapechar_cleanup_device(device);
- device->discipline->cleanup_device(device);
- tape_remove_minor(device);
-
tape_med_state_set(device, MS_UNKNOWN);
- device->tape_state = TS_INIT;
+
+ DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
+ return 0;
}

/*
@@ -479,14 +527,14 @@
tape_generic_probe(struct ccw_device *cdev)
{
struct tape_device *device;
- char *bus_id = cdev->dev.bus_id;

device = tape_alloc_device();
if (IS_ERR(device))
return -ENODEV;
- PRINT_INFO("tape device %s found\n", bus_id);
+ PRINT_INFO("tape device %s found\n", cdev->dev.bus_id);
cdev->dev.driver_data = device;
device->cdev = cdev;
+ device->cdev_id = busid_to_int(cdev->dev.bus_id);
cdev->handler = __tape_do_irq;

ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
@@ -497,15 +545,58 @@

/*
* Driverfs tape remove function.
+ *
+ * This function is called whenever the common I/O layer detects the device
+ * gone. This can happen at any time and we cannot refuse.
*/
void
tape_generic_remove(struct ccw_device *cdev)
{
- ccw_device_set_offline(cdev);
+ struct tape_device * device;
+ struct tape_request * request;
+ struct list_head * l, *n;
+
+ device = cdev->dev.driver_data;
+ DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
+
+ /*
+ * No more requests may be processed. So just post them as i/o errors.
+ */
+ spin_lock_irq(get_ccwdev_lock(device->cdev));
+ list_for_each_safe(l, n, &device->req_queue) {
+ request = list_entry(l, struct tape_request, list);
+ if (request->status == TAPE_REQUEST_IN_IO)
+ request->status = TAPE_REQUEST_DONE;
+ list_del(&request->list);
+
+ /* Decrease ref_count for removed request. */
+ request->device = tape_put_device(device);
+ request->rc = -EIO;
+ if (request->callback != NULL)
+ request->callback(request, request->callback_data);
+ }
+
+ if (device->tape_state != TS_UNUSED && device->tape_state != TS_INIT) {
+ DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
+ device->cdev_id);
+ PRINT_WARN("(%s): Drive in use vanished - expect trouble!\n",
+ device->cdev->dev.bus_id);
+ PRINT_WARN("State was %i\n", device->tape_state);
+ device->tape_state = TS_NOT_OPER;
+ tapeblock_cleanup_device(device);
+ tapechar_cleanup_device(device);
+ device->discipline->cleanup_device(device);
+ tape_remove_minor(device);
+ }
+ device->tape_state = TS_NOT_OPER;
+ tape_med_state_set(device, MS_UNKNOWN);
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+
if (cdev->dev.driver_data != NULL) {
sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
cdev->dev.driver_data = tape_put_device(cdev->dev.driver_data);
}
+
}

/*
@@ -665,7 +756,7 @@
op = "---";
DBF_EVENT(3, "DSTAT : %02x CSTAT: %02x\n",
irb->scsw.dstat,irb->scsw.cstat);
- DBF_EVENT(3, "DEVICE: %s OP\t: %s\n", device->cdev->dev.bus_id,op);
+ DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
sptr = (unsigned int *) irb->ecw;
DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
@@ -815,7 +906,7 @@
spin_lock_irq(get_ccwdev_lock(device->cdev));
rc = __tape_halt_io(device, request);
if (rc == 0) {
- DBF_EVENT(3, "IO stopped on %s\n", device->cdev->dev.bus_id);
+ DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
rc = -ERESTARTSYS;
}
spin_unlock_irq(get_ccwdev_lock(device->cdev));
@@ -823,6 +914,24 @@
}

/*
+ * Handle requests that return an i/o error in the irb.
+ */
+static inline void
+tape_handle_killed_request(
+ struct tape_device *device,
+ struct tape_request *request)
+{
+ if(request != NULL) {
+ /* Set ending status. FIXME: Should the request be retried? */
+ request->rc = -EIO;
+ request->status = TAPE_REQUEST_DONE;
+ __tape_remove_request(device, request);
+ } else {
+ __tape_do_io_list(device);
+ }
+}
+
+/*
* Tape interrupt routine, called from the ccw_device layer
*/
static void
@@ -835,7 +944,7 @@

device = (struct tape_device *) cdev->dev.driver_data;
if (device == NULL) {
- PRINT_ERR("could not get device structure for bus_id %s "
+ PRINT_ERR("could not get device structure for %s "
"in interrupt\n", cdev->dev.bus_id);
return;
}
@@ -843,6 +952,23 @@

DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);

+ /* On special conditions irb is an error pointer */
+ if (IS_ERR(irb)) {
+ switch (PTR_ERR(irb)) {
+ case -ETIMEDOUT:
+ PRINT_WARN("(%s): Request timed out\n",
+ cdev->dev.bus_id);
+ case -EIO:
+ tape_handle_killed_request(device, request);
+ break;
+ default:
+ PRINT_ERR("(%s): Unexpected i/o error %li\n",
+ cdev->dev.bus_id,
+ PTR_ERR(irb));
+ }
+ return;
+ }
+
/* May be an unsolicited irq */
if(request != NULL)
request->rescnt = irb->scsw.count;
@@ -1023,7 +1149,7 @@
#ifdef DBF_LIKE_HELL
debug_set_level(tape_dbf_area, 6);
#endif
- DBF_EVENT(3, "tape init: ($Revision: 1.44 $)\n");
+ DBF_EVENT(3, "tape init: ($Revision: 1.48 $)\n");
tape_proc_init();
tapechar_init ();
tapeblock_init ();
@@ -1048,7 +1174,7 @@
MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
"Michael Holzheu (cotte@xxxxxxxxxx,holzheu@xxxxxxxxxx)");
MODULE_DESCRIPTION("Linux on zSeries channel attached "
- "tape device driver ($Revision: 1.44 $)");
+ "tape device driver ($Revision: 1.48 $)");
MODULE_LICENSE("GPL");

module_init(tape_init);
@@ -1056,9 +1182,9 @@

EXPORT_SYMBOL(tape_dbf_area);
EXPORT_SYMBOL(tape_generic_remove);
-EXPORT_SYMBOL(tape_disable_device);
EXPORT_SYMBOL(tape_generic_probe);
-EXPORT_SYMBOL(tape_enable_device);
+EXPORT_SYMBOL(tape_generic_online);
+EXPORT_SYMBOL(tape_generic_offline);
EXPORT_SYMBOL(tape_put_device);
EXPORT_SYMBOL(tape_get_device_reference);
EXPORT_SYMBOL(tape_state_verbose);
diff -urN linux-2.6/drivers/s390/char/tape_std.c linux-2.6-s390/drivers/s390/char/tape_std.c
--- linux-2.6/drivers/s390/char/tape_std.c Thu Mar 11 03:55:20 2004
+++ linux-2.6-s390/drivers/s390/char/tape_std.c Fri Mar 26 18:25:58 2004
@@ -42,8 +42,8 @@

spin_lock_irq(get_ccwdev_lock(device->cdev));
if (request->callback != NULL) {
- DBF_EVENT(3, "%s: Assignment timeout. Device busy.\n",
- device->cdev->dev.bus_id);
+ DBF_EVENT(3, "%08x: Assignment timeout. Device busy.\n",
+ device->cdev_id);
PRINT_ERR("%s: Assignment timeout. Device busy.\n",
device->cdev->dev.bus_id);
ccw_device_clear(device->cdev, (long) request);
@@ -84,10 +84,10 @@
if (rc != 0) {
PRINT_WARN("%s: assign failed - device might be busy\n",
device->cdev->dev.bus_id);
- DBF_EVENT(3, "%s: assign failed - device might be busy\n",
- device->cdev->dev.bus_id);
+ DBF_EVENT(3, "%08x: assign failed - device might be busy\n",
+ device->cdev_id);
} else {
- DBF_EVENT(3, "%s: Tape assigned\n", device->cdev->dev.bus_id);
+ DBF_EVENT(3, "%08x: Tape assigned\n", device->cdev_id);
}
tape_free_request(request);
return rc;
@@ -102,6 +102,14 @@
int rc;
struct tape_request *request;

+ if (device->tape_state == TS_NOT_OPER) {
+ DBF_EVENT(3, "(%08x): Can't unassign device\n",
+ device->cdev_id);
+ PRINT_WARN("(%s): Can't unassign device - device gone\n",
+ device->cdev->dev.bus_id);
+ return -EIO;
+ }
+
request = tape_alloc_request(2, 11);
if (IS_ERR(request))
return PTR_ERR(request);
@@ -111,10 +119,10 @@
tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);

if ((rc = tape_do_io(device, request)) != 0) {
- DBF_EVENT(3, "%s: Unassign failed\n", device->cdev->dev.bus_id);
+ DBF_EVENT(3, "%08x: Unassign failed\n", device->cdev_id);
PRINT_WARN("%s: Unassign failed\n", device->cdev->dev.bus_id);
} else {
- DBF_EVENT(3, "%s: Tape unassigned\n", device->cdev->dev.bus_id);
+ DBF_EVENT(3, "%08x: Tape unassigned\n", device->cdev_id);
}
tape_free_request(request);
return rc;
-
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