Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6

* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] correct address of _stext with CONFIG_SHARED_KERNEL=y
  [S390] ptrace: fix return value of do_syscall_trace_enter()
  [S390] dasd: fix race between tasklet and dasd_sleep_on

1 files changed, 10 insertions, 7 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index acf222f91f5a..fa2339cb1681 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -37,6 +37,9 @@
  */
 #define DASD_CHANQ_MAX_SIZE 4
 
+#define DASD_SLEEPON_START_TAG  (void *) 1
+#define DASD_SLEEPON_END_TAG    (void *) 2
+
 /*
  * SECTION: exported variables of dasd.c
  */
@@ -1472,7 +1475,10 @@ void dasd_add_request_tail(struct dasd_ccw_req *cqr)
  */
 static void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
 {
-        wake_up((wait_queue_head_t *) data);
+        spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
+        cqr->callback_data = DASD_SLEEPON_END_TAG;
+        spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
+        wake_up(&generic_waitq);
 }
 
 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
@@ -1482,10 +1488,7 @@ static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
 
         device = cqr->startdev;
         spin_lock_irq(get_ccwdev_lock(device->cdev));
-        rc = ((cqr->status == DASD_CQR_DONE ||
-               cqr->status == DASD_CQR_NEED_ERP ||
-               cqr->status == DASD_CQR_TERMINATED) &&
-              list_empty(&cqr->devlist));
+        rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
         spin_unlock_irq(get_ccwdev_lock(device->cdev));
         return rc;
 }
@@ -1573,7 +1576,7 @@ static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
                         wait_event(generic_waitq, !(device->stopped));
 
                 cqr->callback = dasd_wakeup_cb;
-                cqr->callback_data = (void *) &generic_waitq;
+                cqr->callback_data = DASD_SLEEPON_START_TAG;
                 dasd_add_request_tail(cqr);
                 if (interruptible) {
                         rc = wait_event_interruptible(
@@ -1652,7 +1655,7 @@ int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
         }
 
         cqr->callback = dasd_wakeup_cb;
-        cqr->callback_data = (void *) &generic_waitq;
+        cqr->callback_data = DASD_SLEEPON_START_TAG;
         cqr->status = DASD_CQR_QUEUED;
         list_add(&cqr->devlist, &device->ccw_queue);