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authorHorst Hummel <horst.hummel@de.ibm.com>2005-09-03 15:57:58 -0700
committerLinus Torvalds <torvalds@evo.osdl.org>2005-09-05 00:06:26 -0700
commitc6eb7b7703ac4b3401b74f411c8c51ded214bf19 (patch)
tree1cb3563cb83f80347dbc3e4bd30c4635d401e87a /drivers/s390/block/dasd_devmap.c
parent942eaabd5d77522223a311ed9bddaaa3cefde27d (diff)
[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>
Diffstat (limited to 'drivers/s390/block/dasd_devmap.c')
-rw-r--r--drivers/s390/block/dasd_devmap.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index d948566bb24a..bda896d9d788 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -11,7 +11,7 @@
* functions may not be called from interrupt context. In particular
* dasd_get_device is a no-no from interrupt context.
*
- * $Revision: 1.40 $
+ * $Revision: 1.43 $
*/
#include <linux/config.h>
@@ -513,6 +513,7 @@ dasd_create_device(struct ccw_device *cdev)
if (!devmap->device) {
devmap->device = device;
device->devindex = devmap->devindex;
+ device->features = devmap->features;
get_device(&cdev->dev);
device->cdev = cdev;
rc = 0;
@@ -643,6 +644,8 @@ dasd_ro_store(struct device *dev, struct device_attribute *attr, const char *buf
devmap->features |= DASD_FEATURE_READONLY;
else
devmap->features &= ~DASD_FEATURE_READONLY;
+ if (devmap->device)
+ devmap->device->features = devmap->features;
if (devmap->device && devmap->device->gdp)
set_disk_ro(devmap->device->gdp, ro_flag);
spin_unlock(&dasd_devmap_lock);
@@ -758,7 +761,8 @@ dasd_set_feature(struct ccw_device *cdev, int feature, int flag)
devmap->features |= feature;
else
devmap->features &= ~feature;
-
+ if (devmap->device)
+ devmap->device->features = devmap->features;
spin_unlock(&dasd_devmap_lock);
return 0;
}