s390/dasd: add shutdown action
Add a mechanism to wait for outstanding IO during shutdown.
Schedule the block_bh and device_bh and wait until our request queues
are empty.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index f350912..2678a83 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -82,6 +82,7 @@
static wait_queue_head_t dasd_init_waitq;
static wait_queue_head_t dasd_flush_wq;
static wait_queue_head_t generic_waitq;
+static wait_queue_head_t shutdown_waitq;
/*
* Allocate memory for a new device structure.
@@ -1994,6 +1995,8 @@
/* Now check if the head of the ccw queue needs to be started. */
__dasd_device_start_head(device);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
+ if (waitqueue_active(&shutdown_waitq))
+ wake_up(&shutdown_waitq);
dasd_put_device(device);
}
@@ -2632,6 +2635,8 @@
__dasd_block_start_head(block);
spin_unlock(&block->queue_lock);
spin_unlock_irq(&block->request_queue_lock);
+ if (waitqueue_active(&shutdown_waitq))
+ wake_up(&shutdown_waitq);
dasd_put_device(block->base);
}
@@ -3474,6 +3479,32 @@
}
EXPORT_SYMBOL_GPL(dasd_get_sense);
+static inline int _wait_for_empty_queues(struct dasd_device *device)
+{
+ if (device->block)
+ return list_empty(&device->ccw_queue) &&
+ list_empty(&device->block->ccw_queue);
+ else
+ return list_empty(&device->ccw_queue);
+}
+
+void dasd_generic_shutdown(struct ccw_device *cdev)
+{
+ struct dasd_device *device;
+
+ device = dasd_device_from_cdev(cdev);
+ if (IS_ERR(device))
+ return;
+
+ if (device->block)
+ dasd_schedule_block_bh(device->block);
+
+ dasd_schedule_device_bh(device);
+
+ wait_event(shutdown_waitq, _wait_for_empty_queues(device));
+}
+EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
+
static int __init dasd_init(void)
{
int rc;
@@ -3481,6 +3512,7 @@
init_waitqueue_head(&dasd_init_waitq);
init_waitqueue_head(&dasd_flush_wq);
init_waitqueue_head(&generic_waitq);
+ init_waitqueue_head(&shutdown_waitq);
/* register 'common' DASD debug area, used for all DBF_XXX calls */
dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));