[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_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index 980c555..789595b 100644
--- a/drivers/s390/block/dasd_ioctl.c
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -7,7 +7,7 @@
* Bugreports.to..: <Linux390@de.ibm.com>
* (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
*
- * $Revision: 1.45 $
+ * $Revision: 1.47 $
*
* i/o controls for the dasd driver.
*/
@@ -296,7 +296,6 @@
{
struct dasd_device *device;
struct format_data_t fdata;
- int feature_ro;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
@@ -308,10 +307,7 @@
if (device == NULL)
return -ENODEV;
- feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
- if (feature_ro < 0)
- return feature_ro;
- if (feature_ro)
+ if (device->features & DASD_FEATURE_READONLY)
return -EROFS;
if (copy_from_user(&fdata, (void __user *) args,
sizeof (struct format_data_t)))
@@ -384,7 +380,7 @@
struct dasd_device *device;
struct dasd_information2_t *dasd_info;
unsigned long flags;
- int rc, feature_ro;
+ int rc;
struct ccw_device *cdev;
device = bdev->bd_disk->private_data;
@@ -394,10 +390,6 @@
if (!device->discipline->fill_info)
return -EINVAL;
- feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
- if (feature_ro < 0)
- return feature_ro;
-
dasd_info = kmalloc(sizeof(struct dasd_information2_t), GFP_KERNEL);
if (dasd_info == NULL)
return -ENOMEM;
@@ -427,7 +419,8 @@
(dasd_check_blocksize(device->bp_block)))
dasd_info->format = DASD_FORMAT_NONE;
- dasd_info->features |= feature_ro;
+ dasd_info->features |=
+ ((device->features & DASD_FEATURE_READONLY) != 0);
if (device->discipline)
memcpy(dasd_info->type, device->discipline->name, 4);