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authorStefan Weinhuber <wein@de.ibm.com>2010-03-08 12:26:24 +0100
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>2010-03-08 12:26:27 +0100
commit33b62a30f78536b976183cc764c08038ac011e0a (patch)
tree60a18b4478c68082835fa6fee9a24bb1e7e8b312 /drivers/s390/block/dasd_devmap.c
parent584dfddfce1bd81d877f14de2b56d4bc747af821 (diff)
[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>
Diffstat (limited to 'drivers/s390/block/dasd_devmap.c')
-rw-r--r--drivers/s390/block/dasd_devmap.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index d49766f3b94..8e23919c870 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -742,6 +742,7 @@ dasd_ro_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct dasd_devmap *devmap;
+ struct dasd_device *device;
int val;
char *endp;
@@ -758,12 +759,14 @@ dasd_ro_store(struct device *dev, struct device_attribute *attr,
devmap->features |= DASD_FEATURE_READONLY;
else
devmap->features &= ~DASD_FEATURE_READONLY;
- if (devmap->device)
- devmap->device->features = devmap->features;
- if (devmap->device && devmap->device->block
- && devmap->device->block->gdp)
- set_disk_ro(devmap->device->block->gdp, val);
+ device = devmap->device;
+ if (device) {
+ device->features = devmap->features;
+ val = val || test_bit(DASD_FLAG_DEVICE_RO, &device->flags);
+ }
spin_unlock(&dasd_devmap_lock);
+ if (device && device->block && device->block->gdp)
+ set_disk_ro(device->block->gdp, val);
return count;
}