[patch 08/11] dasd: use a generic wait_queue for sleep_on

Martin Schwidefsky
2008-05-29T13:04:56Z

[-- Attachment #1: 008-dasd-waitqueue.diff --]
[-- Type: text/plain, Size: 4307 bytes --]

From: Stefan Haberland <stefan.haberland@de.ibm.com>

Use a generic wait_queue to prevent the wait_queue in dasd_sleep_on_
functions from being referenced by callback_data while it does not
exist any more.

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

drivers/s390/block/dasd.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)

Index: quilt-2.6/drivers/s390/block/dasd.c
===================================================================
--- quilt-2.6.orig/drivers/s390/block/dasd.c
+++ quilt-2.6/drivers/s390/block/dasd.c
@@ -63,6 +63,7 @@ static void dasd_return_cqr_cb(struct da
*/
static wait_queue_head_t dasd_init_waitq;
static wait_queue_head_t dasd_flush_wq;
+static wait_queue_head_t generic_waitq;

/*
* Allocate memory for a new device structure.
@@ -1151,11 +1152,15 @@ static void __dasd_device_process_final_
struct list_head *l, *n;
struct dasd_ccw_req *cqr;
struct dasd_block *block;
+ void (*callback)(struct dasd_ccw_req *, void *data);
+ void *callback_data;

list_for_each_safe(l, n, final_queue) {
cqr = list_entry(l, struct dasd_ccw_req, devlist);
list_del_init(&cqr->devlist);
block = cqr->block;
+ callback = cqr->callback;
+ callback_data = cqr->callback_data;
if (block)
spin_lock_bh(&block->queue_lock);
switch (cqr->status) {
@@ -1176,7 +1181,7 @@ static void __dasd_device_process_final_
BUG();
}
if (cqr->callback != NULL)
- (cqr->callback)(cqr, cqr->callback_data);
+ (callback)(cqr, callback_data);
if (block)
spin_unlock_bh(&block->queue_lock);
}
@@ -1406,17 +1411,15 @@ static inline int _wait_for_wakeup(struc
*/
int dasd_sleep_on(struct dasd_ccw_req *cqr)
{
- wait_queue_head_t wait_q;
struct dasd_device *device;
int rc;

device = cqr->startdev;

- init_waitqueue_head (&wait_q);
cqr->callback = dasd_wakeup_cb;
- cqr->callback_data = (void *) &wait_q;
+ cqr->callback_data = (void *) &generic_waitq;
dasd_add_request_tail(cqr);
- wait_event(wait_q, _wait_for_wakeup(cqr));
+ wait_event(generic_waitq, _wait_for_wakeup(cqr));

/* Request status is either done or failed. */
rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
@@ -1429,20 +1432,18 @@ int dasd_sleep_on(struct dasd_ccw_req *c
*/
int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
{
- wait_queue_head_t wait_q;
struct dasd_device *device;
int rc;

device = cqr->startdev;
- init_waitqueue_head (&wait_q);
cqr->callback = dasd_wakeup_cb;
- cqr->callback_data = (void *) &wait_q;
+ cqr->callback_data = (void *) &generic_waitq;
dasd_add_request_tail(cqr);
- rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
+ rc = wait_event_interruptible(generic_waitq, _wait_for_wakeup(cqr));
if (rc == -ERESTARTSYS) {
dasd_cancel_req(cqr);
/* wait (non-interruptible) for final status */
- wait_event(wait_q, _wait_for_wakeup(cqr));
+ wait_event(generic_waitq, _wait_for_wakeup(cqr));
}
rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
return rc;
@@ -1466,7 +1467,6 @@ static inline int _dasd_term_running_cqr

int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
{
- wait_queue_head_t wait_q;
struct dasd_device *device;
int rc;

@@ -1478,9 +1478,8 @@ int dasd_sleep_on_immediatly(struct dasd
return rc;
}

- init_waitqueue_head (&wait_q);
cqr->callback = dasd_wakeup_cb;
- cqr->callback_data = (void *) &wait_q;
+ cqr->callback_data = (void *) &generic_waitq;
cqr->status = DASD_CQR_QUEUED;
list_add(&cqr->devlist, &device->ccw_queue);

@@ -1489,7 +1488,7 @@ int dasd_sleep_on_immediatly(struct dasd

spin_unlock_irq(get_ccwdev_lock(device->cdev));

- wait_event(wait_q, _wait_for_wakeup(cqr));
+ wait_event(generic_waitq, _wait_for_wakeup(cqr));

/* Request status is either done or failed. */
rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
@@ -2430,6 +2429,7 @@ static int __init dasd_init(void)

init_waitqueue_head(&dasd_init_waitq);
init_waitqueue_head(&dasd_flush_wq);
+ init_waitqueue_head(&generic_waitq);

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