[S390] dasd: do path verification for paths added at runtime

When a new path is added at runtime, the CIO layer will call the drivers
path_event callback. The DASD device driver uses this callback to trigger
a path verification for the new path. The driver will use only those
paths for I/O, which have been successfully verified.

Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index 500678d7116c..ba038ef57606 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -231,6 +231,7 @@ struct dasd_ccw_req {
 /* per dasd_ccw_req flags */
 #define DASD_CQR_FLAGS_USE_ERP   0      /* use ERP for this request */
 #define DASD_CQR_FLAGS_FAILFAST  1      /* FAILFAST */
+#define DASD_CQR_VERIFY_PATH     2      /* path verification request */
 
 /* Signature for error recovery functions. */
 typedef struct dasd_ccw_req *(*dasd_erp_fn_t) (struct dasd_ccw_req *);
@@ -287,6 +288,14 @@ struct dasd_discipline {
         int (*do_analysis) (struct dasd_block *);
 
         /*
+         * This function is called, when new paths become available.
+         * Disciplins may use this callback to do necessary setup work,
+         * e.g. verify that new path is compatible with the current
+         * configuration.
+         */
+        int (*verify_path)(struct dasd_device *, __u8);
+
+        /*
          * Last things to do when a device is set online, and first things
          * when it is set offline.
          */
@@ -362,6 +371,13 @@ extern struct dasd_discipline *dasd_diag_discipline_pointer;
 #define DASD_EER_STATECHANGE 3
 #define DASD_EER_PPRCSUSPEND 4
 
+struct dasd_path {
+        __u8 opm;
+        __u8 tbvpm;
+        __u8 ppm;
+        __u8 npm;
+};
+
 struct dasd_device {
         /* Block device stuff. */
         struct dasd_block *block;
@@ -377,6 +393,7 @@ struct dasd_device {
         struct dasd_discipline *discipline;
         struct dasd_discipline *base_discipline;
         char *private;
+        struct dasd_path path_data;
 
         /* Device state and target state. */
         int state, target;
@@ -620,10 +637,15 @@ void dasd_generic_remove (struct ccw_device *cdev);
 int dasd_generic_set_online(struct ccw_device *, struct dasd_discipline *);
 int dasd_generic_set_offline (struct ccw_device *cdev);
 int dasd_generic_notify(struct ccw_device *, int);
+int dasd_generic_last_path_gone(struct dasd_device *);
+int dasd_generic_path_operational(struct dasd_device *);
+
 void dasd_generic_handle_state_change(struct dasd_device *);
 int dasd_generic_pm_freeze(struct ccw_device *);
 int dasd_generic_restore_device(struct ccw_device *);
 enum uc_todo dasd_generic_uc_handler(struct ccw_device *, struct irb *);
+void dasd_generic_path_event(struct ccw_device *, int *);
+int dasd_generic_verify_path(struct dasd_device *, __u8);
 
 int dasd_generic_read_dev_chars(struct dasd_device *, int, void *, int);
 char *dasd_get_sense(struct irb *);