[S390] tape: add medium state notifications

Add uevent notifications for tape cartridge load and tape
cartridge unload events.

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

1 files changed, 59 insertions, 9 deletions

diff --git a/drivers/s390/char/tape_core.c b/drivers/s390/char/tape_core.c
index 6c408670e08d..b3a3e8e8656e 100644
--- a/drivers/s390/char/tape_core.c
+++ b/drivers/s390/char/tape_core.c
@@ -209,29 +209,79 @@ tape_state_set(struct tape_device *device, enum tape_state newstate)
         wake_up(&device->state_change_wq);
 }
 
+struct tape_med_state_work_data {
+        struct tape_device *device;
+        enum tape_medium_state state;
+        struct work_struct  work;
+};
+
+static void
+tape_med_state_work_handler(struct work_struct *work)
+{
+        static char env_state_loaded[] = "MEDIUM_STATE=LOADED";
+        static char env_state_unloaded[] = "MEDIUM_STATE=UNLOADED";
+        struct tape_med_state_work_data *p =
+                container_of(work, struct tape_med_state_work_data, work);
+        struct tape_device *device = p->device;
+        char *envp[] = { NULL, NULL };
+
+        switch (p->state) {
+        case MS_UNLOADED:
+                pr_info("%s: The tape cartridge has been successfully "
+                        "unloaded\n", dev_name(&device->cdev->dev));
+                envp[0] = env_state_unloaded;
+                kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
+                break;
+        case MS_LOADED:
+                pr_info("%s: A tape cartridge has been mounted\n",
+                        dev_name(&device->cdev->dev));
+                envp[0] = env_state_loaded;
+                kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
+                break;
+        default:
+                break;
+        }
+        tape_put_device(device);
+        kfree(p);
+}
+
+static void
+tape_med_state_work(struct tape_device *device, enum tape_medium_state state)
+{
+        struct tape_med_state_work_data *p;
+
+        p = kzalloc(sizeof(*p), GFP_ATOMIC);
+        if (p) {
+                INIT_WORK(&p->work, tape_med_state_work_handler);
+                p->device = tape_get_device(device);
+                p->state = state;
+                schedule_work(&p->work);
+        }
+}
+
 void
 tape_med_state_set(struct tape_device *device, enum tape_medium_state newstate)
 {
-        if (device->medium_state == newstate)
+        enum tape_medium_state oldstate;
+
+        oldstate = device->medium_state;
+        if (oldstate == newstate)
                 return;
+        device->medium_state = newstate;
         switch(newstate){
         case MS_UNLOADED:
                 device->tape_generic_status |= GMT_DR_OPEN(~0);
-                if (device->medium_state == MS_LOADED)
-                        pr_info("%s: The tape cartridge has been successfully "
-                                "unloaded\n", dev_name(&device->cdev->dev));
+                if (oldstate == MS_LOADED)
+                        tape_med_state_work(device, MS_UNLOADED);
                 break;
         case MS_LOADED:
                 device->tape_generic_status &= ~GMT_DR_OPEN(~0);
-                if (device->medium_state == MS_UNLOADED)
-                        pr_info("%s: A tape cartridge has been mounted\n",
-                                dev_name(&device->cdev->dev));
+                if (oldstate == MS_UNLOADED)
+                        tape_med_state_work(device, MS_LOADED);
                 break;
         default:
-                // print nothing
                 break;
         }
-        device->medium_state = newstate;
         wake_up(&device->state_change_wq);
 }