[PATCH] s390: deadlock in dasd_devmap
Reintroduce a read-only copy of the devmap features in the device struct.
This is necessary to solve a deadlock on the dasd_devmap_lock which is
acquired by dasd_get_features called from the dasd tasklet. The current
implementation of devmap doesn't allow to call any devmap function from
interrupt or softirq context.
Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index d5f5398..8fc891a 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -7,7 +7,7 @@
* Bugreports.to..: <Linux390@de.ibm.com>
* (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
*
- * $Revision: 1.165 $
+ * $Revision: 1.167 $
*/
#include <linux/config.h>
@@ -1131,17 +1131,13 @@
request_queue_t *queue;
struct request *req;
struct dasd_ccw_req *cqr;
- int nr_queued, feature_ro;
+ int nr_queued;
queue = device->request_queue;
/* No queue ? Then there is nothing to do. */
if (queue == NULL)
return;
- feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
- if (feature_ro < 0) /* no devmap */
- return;
-
/*
* We requeue request from the block device queue to the ccw
* queue only in two states. In state DASD_STATE_READY the
@@ -1162,7 +1158,8 @@
nr_queued < DASD_CHANQ_MAX_SIZE) {
req = elv_next_request(queue);
- if (feature_ro && rq_data_dir(req) == WRITE) {
+ if (device->features & DASD_FEATURE_READONLY &&
+ rq_data_dir(req) == WRITE) {
DBF_DEV_EVENT(DBF_ERR, device,
"Rejecting write request %p",
req);
@@ -1814,17 +1811,13 @@
{
struct dasd_device *device;
- int feature_diag, rc;
+ int rc;
device = dasd_create_device(cdev);
if (IS_ERR(device))
return PTR_ERR(device);
- feature_diag = dasd_get_feature(cdev, DASD_FEATURE_USEDIAG);
- if (feature_diag < 0)
- return feature_diag;
-
- if (feature_diag) {
+ if (device->features & DASD_FEATURE_USEDIAG) {
if (!dasd_diag_discipline_pointer) {
printk (KERN_WARNING
"dasd_generic couldn't online device %s "