[S390] dasd: automatic recognition of read-only devices
In z/VM it is possible to attach a device as read-only. To prevent
unintentional write requests and subsequent I/O errors, we can detect
this configuration using the z/VM DIAG 210 interface and set the
respective linux block device to read-only as well.
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c
index 94f92a1..30a1ca3 100644
--- a/drivers/s390/block/dasd_genhd.c
+++ b/drivers/s390/block/dasd_genhd.c
@@ -70,7 +70,8 @@
}
len += sprintf(gdp->disk_name + len, "%c", 'a'+(base->devindex%26));
- if (block->base->features & DASD_FEATURE_READONLY)
+ if (base->features & DASD_FEATURE_READONLY ||
+ test_bit(DASD_FLAG_DEVICE_RO, &base->flags))
set_disk_ro(gdp, 1);
gdp->private_data = block;
gdp->queue = block->request_queue;