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[S390] dasd: fix device shutdown process.
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Fix clear_IO handling (need to wait for interrupt) and
introduced error-handling in shutdown processing.

Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Horst Hummel authored and Martin Schwidefsky committed Aug 30, 2006
1 parent af313e5 commit 8f61701
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Showing 2 changed files with 137 additions and 65 deletions.
192 changes: 131 additions & 61 deletions drivers/s390/block/dasd.c
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Original file line number Diff line number Diff line change
Expand Up @@ -52,14 +52,15 @@ static void dasd_setup_queue(struct dasd_device * device);
static void dasd_free_queue(struct dasd_device * device);
static void dasd_flush_request_queue(struct dasd_device *);
static void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
static void dasd_flush_ccw_queue(struct dasd_device *, int);
static int dasd_flush_ccw_queue(struct dasd_device *, int);
static void dasd_tasklet(struct dasd_device *);
static void do_kick_device(void *data);

/*
* SECTION: Operations on the device structure.
*/
static wait_queue_head_t dasd_init_waitq;
static wait_queue_head_t dasd_flush_wq;

/*
* Allocate memory for a new device structure.
Expand Down Expand Up @@ -121,7 +122,7 @@ dasd_free_device(struct dasd_device *device)
/*
* Make a new device known to the system.
*/
static inline int
static int
dasd_state_new_to_known(struct dasd_device *device)
{
int rc;
Expand All @@ -145,7 +146,7 @@ dasd_state_new_to_known(struct dasd_device *device)
/*
* Let the system forget about a device.
*/
static inline void
static int
dasd_state_known_to_new(struct dasd_device * device)
{
/* Disable extended error reporting for this device. */
Expand All @@ -163,12 +164,13 @@ dasd_state_known_to_new(struct dasd_device * device)

/* Give up reference we took in dasd_state_new_to_known. */
dasd_put_device(device);
return 0;
}

/*
* Request the irq line for the device.
*/
static inline int
static int
dasd_state_known_to_basic(struct dasd_device * device)
{
int rc;
Expand All @@ -192,17 +194,23 @@ dasd_state_known_to_basic(struct dasd_device * device)
/*
* Release the irq line for the device. Terminate any running i/o.
*/
static inline void
static int
dasd_state_basic_to_known(struct dasd_device * device)
{
int rc;

dasd_gendisk_free(device);
dasd_flush_ccw_queue(device, 1);
rc = dasd_flush_ccw_queue(device, 1);
if (rc)
return rc;

DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
if (device->debug_area != NULL) {
debug_unregister(device->debug_area);
device->debug_area = NULL;
}
device->state = DASD_STATE_KNOWN;
return 0;
}

/*
Expand All @@ -219,7 +227,7 @@ dasd_state_basic_to_known(struct dasd_device * device)
* In case the analysis returns an error, the device setup is stopped
* (a fake disk was already added to allow formatting).
*/
static inline int
static int
dasd_state_basic_to_ready(struct dasd_device * device)
{
int rc;
Expand Down Expand Up @@ -247,33 +255,39 @@ dasd_state_basic_to_ready(struct dasd_device * device)
* Forget format information. Check if the target level is basic
* and if it is create fake disk for formatting.
*/
static inline void
static int
dasd_state_ready_to_basic(struct dasd_device * device)
{
dasd_flush_ccw_queue(device, 0);
int rc;

rc = dasd_flush_ccw_queue(device, 0);
if (rc)
return rc;
dasd_destroy_partitions(device);
dasd_flush_request_queue(device);
device->blocks = 0;
device->bp_block = 0;
device->s2b_shift = 0;
device->state = DASD_STATE_BASIC;
return 0;
}

/*
* Back to basic.
*/
static inline void
static int
dasd_state_unfmt_to_basic(struct dasd_device * device)
{
device->state = DASD_STATE_BASIC;
return 0;
}

/*
* Make the device online and schedule the bottom half to start
* the requeueing of requests from the linux request queue to the
* ccw queue.
*/
static inline int
static int
dasd_state_ready_to_online(struct dasd_device * device)
{
device->state = DASD_STATE_ONLINE;
Expand All @@ -284,16 +298,17 @@ dasd_state_ready_to_online(struct dasd_device * device)
/*
* Stop the requeueing of requests again.
*/
static inline void
static int
dasd_state_online_to_ready(struct dasd_device * device)
{
device->state = DASD_STATE_READY;
return 0;
}

/*
* Device startup state changes.
*/
static inline int
static int
dasd_increase_state(struct dasd_device *device)
{
int rc;
Expand Down Expand Up @@ -329,30 +344,37 @@ dasd_increase_state(struct dasd_device *device)
/*
* Device shutdown state changes.
*/
static inline int
static int
dasd_decrease_state(struct dasd_device *device)
{
int rc;

rc = 0;
if (device->state == DASD_STATE_ONLINE &&
device->target <= DASD_STATE_READY)
dasd_state_online_to_ready(device);
rc = dasd_state_online_to_ready(device);

if (device->state == DASD_STATE_READY &&
if (!rc &&
device->state == DASD_STATE_READY &&
device->target <= DASD_STATE_BASIC)
dasd_state_ready_to_basic(device);
rc = dasd_state_ready_to_basic(device);

if (device->state == DASD_STATE_UNFMT &&
if (!rc &&
device->state == DASD_STATE_UNFMT &&
device->target <= DASD_STATE_BASIC)
dasd_state_unfmt_to_basic(device);
rc = dasd_state_unfmt_to_basic(device);

if (device->state == DASD_STATE_BASIC &&
if (!rc &&
device->state == DASD_STATE_BASIC &&
device->target <= DASD_STATE_KNOWN)
dasd_state_basic_to_known(device);
rc = dasd_state_basic_to_known(device);

if (device->state == DASD_STATE_KNOWN &&
if (!rc &&
device->state == DASD_STATE_KNOWN &&
device->target <= DASD_STATE_NEW)
dasd_state_known_to_new(device);
rc = dasd_state_known_to_new(device);

return 0;
return rc;
}

/*
Expand Down Expand Up @@ -701,6 +723,7 @@ dasd_term_IO(struct dasd_ccw_req * cqr)
cqr->retries--;
cqr->status = DASD_CQR_CLEAR;
cqr->stopclk = get_clock();
cqr->starttime = 0;
DBF_DEV_EVENT(DBF_DEBUG, device,
"terminate cqr %p successful",
cqr);
Expand Down Expand Up @@ -978,6 +1001,7 @@ dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
cqr->status = DASD_CQR_QUEUED;
dasd_clear_timer(device);
wake_up(&dasd_flush_wq);
dasd_schedule_bh(device);
return;
}
Expand Down Expand Up @@ -1241,6 +1265,10 @@ __dasd_check_expire(struct dasd_device * device)
cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
if (cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) {
if (time_after_eq(jiffies, cqr->expires + cqr->starttime)) {
DEV_MESSAGE(KERN_ERR, device,
"internal error - timeout (%is) expired "
"for cqr %p (%i retries left)",
(cqr->expires/HZ), cqr, cqr->retries);
if (device->discipline->term_IO(cqr) != 0)
/* Hmpf, try again in 1/10 sec */
dasd_set_timer(device, 10);
Expand Down Expand Up @@ -1285,46 +1313,100 @@ __dasd_start_head(struct dasd_device * device)
dasd_set_timer(device, 50);
}

static inline int
_wait_for_clear(struct dasd_ccw_req *cqr)
{
return (cqr->status == DASD_CQR_QUEUED);
}

/*
* Remove requests from the ccw queue.
* Remove all requests from the ccw queue (all = '1') or only block device
* requests in case all = '0'.
* Take care of the erp-chain (chained via cqr->refers) and remove either
* the whole erp-chain or none of the erp-requests.
* If a request is currently running, term_IO is called and the request
* is re-queued. Prior to removing the terminated request we need to wait
* for the clear-interrupt.
* In case termination is not possible we stop processing and just finishing
* the already moved requests.
*/
static void
static int
dasd_flush_ccw_queue(struct dasd_device * device, int all)
{
struct dasd_ccw_req *cqr, *orig, *n;
int rc, i;

struct list_head flush_queue;
struct list_head *l, *n;
struct dasd_ccw_req *cqr;

INIT_LIST_HEAD(&flush_queue);
spin_lock_irq(get_ccwdev_lock(device->cdev));
list_for_each_safe(l, n, &device->ccw_queue) {
cqr = list_entry(l, struct dasd_ccw_req, list);
rc = 0;
restart:
list_for_each_entry_safe(cqr, n, &device->ccw_queue, list) {
/* get original request of erp request-chain */
for (orig = cqr; orig->refers != NULL; orig = orig->refers);

/* Flush all request or only block device requests? */
if (all == 0 && cqr->callback == dasd_end_request_cb)
if (all == 0 && cqr->callback != dasd_end_request_cb &&
orig->callback != dasd_end_request_cb) {
continue;
if (cqr->status == DASD_CQR_IN_IO)
device->discipline->term_IO(cqr);
if (cqr->status != DASD_CQR_DONE ||
cqr->status != DASD_CQR_FAILED) {
cqr->status = DASD_CQR_FAILED;
}
/* Check status and move request to flush_queue */
switch (cqr->status) {
case DASD_CQR_IN_IO:
rc = device->discipline->term_IO(cqr);
if (rc) {
/* unable to terminate requeust */
DEV_MESSAGE(KERN_ERR, device,
"dasd flush ccw_queue is unable "
" to terminate request %p",
cqr);
/* stop flush processing */
goto finished;
}
break;
case DASD_CQR_QUEUED:
case DASD_CQR_ERROR:
/* set request to FAILED */
cqr->stopclk = get_clock();
cqr->status = DASD_CQR_FAILED;
break;
default: /* do not touch the others */
break;
}
/* Rechain request (including erp chain) */
for (i = 0; cqr != NULL; cqr = cqr->refers, i++) {
cqr->endclk = get_clock();
list_move_tail(&cqr->list, &flush_queue);
}
if (i > 1)
/* moved more than one request - need to restart */
goto restart;
}

finished:
spin_unlock_irq(get_ccwdev_lock(device->cdev));
/* Now call the callback function of flushed requests */
restart_cb:
list_for_each_entry_safe(cqr, n, &flush_queue, list) {
if (cqr->status == DASD_CQR_CLEAR) {
/* wait for clear interrupt! */
wait_event(dasd_flush_wq, _wait_for_clear(cqr));
cqr->status = DASD_CQR_FAILED;
}
/* Process finished ERP request. */
if (cqr->refers) {
__dasd_process_erp(device, cqr);
continue;
/* restart list_for_xx loop since dasd_process_erp
* might remove multiple elements */
goto restart_cb;
}
/* Rechain request on device request queue */
/* call the callback function */
cqr->endclk = get_clock();
list_move_tail(&cqr->list, &flush_queue);
}
spin_unlock_irq(get_ccwdev_lock(device->cdev));
/* Now call the callback function of flushed requests */
list_for_each_safe(l, n, &flush_queue) {
cqr = list_entry(l, struct dasd_ccw_req, list);
if (cqr->callback != NULL)
(cqr->callback)(cqr, cqr->callback_data);
}
return rc;
}

/*
Expand Down Expand Up @@ -1510,10 +1592,8 @@ dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
if (device->discipline->term_IO) {
cqr->retries = -1;
device->discipline->term_IO(cqr);
/*nished =
* wait (non-interruptible) for final status
* because signal ist still pending
*/
/* wait (non-interruptible) for final status
* because signal ist still pending */
spin_unlock_irq(get_ccwdev_lock(device->cdev));
wait_event(wait_q, _wait_for_wakeup(cqr));
spin_lock_irq(get_ccwdev_lock(device->cdev));
Expand Down Expand Up @@ -1546,19 +1626,11 @@ static inline int
_dasd_term_running_cqr(struct dasd_device *device)
{
struct dasd_ccw_req *cqr;
int rc;

if (list_empty(&device->ccw_queue))
return 0;
cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
rc = device->discipline->term_IO(cqr);
if (rc == 0) {
/* termination successful */
cqr->status = DASD_CQR_QUEUED;
cqr->startclk = cqr->stopclk = 0;
cqr->starttime = 0;
}
return rc;
return device->discipline->term_IO(cqr);
}

int
Expand Down Expand Up @@ -1726,10 +1798,7 @@ dasd_flush_request_queue(struct dasd_device * device)
return;

spin_lock_irq(&device->request_queue_lock);
while (!list_empty(&device->request_queue->queue_head)) {
req = elv_next_request(device->request_queue);
if (req == NULL)
break;
while ((req = elv_next_request(device->request_queue))) {
blkdev_dequeue_request(req);
dasd_end_request(req, 0);
}
Expand Down Expand Up @@ -2091,6 +2160,7 @@ dasd_init(void)
int rc;

init_waitqueue_head(&dasd_init_waitq);
init_waitqueue_head(&dasd_flush_wq);

/* register 'common' DASD debug area, used for all DBF_XXX calls */
dasd_debug_area = debug_register("dasd", 1, 2, 8 * sizeof (long));
Expand Down
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