[S390] cio: split PGID settings and status

Split setting (driver wants feature enabled) and status (feature
setup was successful) for PGID related ccw device features so that
setup errors can be detected. Previously, incorrectly handled setup
errors could in rare cases lead to erratic I/O behavior and
permanently unusuable devices.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/drivers/s390/cio/device_ops.c b/drivers/s390/cio/device_ops.c
index 5ab90ec..d4be16a 100644
--- a/drivers/s390/cio/device_ops.c
+++ b/drivers/s390/cio/device_ops.c
@@ -46,6 +46,7 @@ int ccw_device_set_options_mask(struct ccw_device *cdev, unsigned long flags)
 	cdev->private->options.repall = (flags & CCWDEV_REPORT_ALL) != 0;
 	cdev->private->options.pgroup = (flags & CCWDEV_DO_PATHGROUP) != 0;
 	cdev->private->options.force = (flags & CCWDEV_ALLOW_FORCE) != 0;
+	cdev->private->options.mpath = (flags & CCWDEV_DO_MULTIPATH) != 0;
 	return 0;
 }
 
@@ -74,6 +75,7 @@ int ccw_device_set_options(struct ccw_device *cdev, unsigned long flags)
 	cdev->private->options.repall |= (flags & CCWDEV_REPORT_ALL) != 0;
 	cdev->private->options.pgroup |= (flags & CCWDEV_DO_PATHGROUP) != 0;
 	cdev->private->options.force |= (flags & CCWDEV_ALLOW_FORCE) != 0;
+	cdev->private->options.mpath |= (flags & CCWDEV_DO_MULTIPATH) != 0;
 	return 0;
 }
 
@@ -90,9 +92,34 @@ void ccw_device_clear_options(struct ccw_device *cdev, unsigned long flags)
 	cdev->private->options.repall &= (flags & CCWDEV_REPORT_ALL) == 0;
 	cdev->private->options.pgroup &= (flags & CCWDEV_DO_PATHGROUP) == 0;
 	cdev->private->options.force &= (flags & CCWDEV_ALLOW_FORCE) == 0;
+	cdev->private->options.mpath &= (flags & CCWDEV_DO_MULTIPATH) == 0;
 }
 
 /**
+ * ccw_device_is_pathgroup - determine if paths to this device are grouped
+ * @cdev: ccw device
+ *
+ * Return non-zero if there is a path group, zero otherwise.
+ */
+int ccw_device_is_pathgroup(struct ccw_device *cdev)
+{
+	return cdev->private->flags.pgroup;
+}
+EXPORT_SYMBOL(ccw_device_is_pathgroup);
+
+/**
+ * ccw_device_is_multipath - determine if device is operating in multipath mode
+ * @cdev: ccw device
+ *
+ * Return non-zero if device is operating in multipath mode, zero otherwise.
+ */
+int ccw_device_is_multipath(struct ccw_device *cdev)
+{
+	return cdev->private->flags.mpath;
+}
+EXPORT_SYMBOL(ccw_device_is_multipath);
+
+/**
  * ccw_device_clear() - terminate I/O request processing
  * @cdev: target ccw device
  * @intparm: interruption parameter; value is only used if no I/O is