[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>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/s390/block/dasd_3990_erp.c b/drivers/s390/block/dasd_3990_erp.c
index 44796ba4eb9b..51224f76b980 100644
--- a/drivers/s390/block/dasd_3990_erp.c
+++ b/drivers/s390/block/dasd_3990_erp.c
@@ -1045,6 +1045,10 @@ dasd_3990_erp_com_rej(struct dasd_ccw_req * erp, char *sense)
 
                 erp->retries = 5;
 
+        } else if (sense[1] & SNS1_WRITE_INHIBITED) {
+                dev_err(&device->cdev->dev, "An I/O request was rejected"
+                        " because writing is inhibited\n");
+                erp = dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
         } else {
                 /* fatal error -  set status to FAILED
                    internal error 09 - Command Reject */