SCSI: add asynchronous event notification API

Originally based on a patch by Kristen Carlson Accardi @ Intel.
Copious input from James Bottomley.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 47 insertions, 0 deletions

diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index d531ceeb0d8c..f374fdcb6815 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -268,6 +268,7 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work)
         struct scsi_device *sdev;
         struct device *parent;
         struct scsi_target *starget;
+        struct list_head *this, *tmp;
         unsigned long flags;
 
         sdev = container_of(work, struct scsi_device, ew.work);
@@ -282,6 +283,16 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work)
         list_del(&sdev->starved_entry);
         spin_unlock_irqrestore(sdev->host->host_lock, flags);
 
+        cancel_work_sync(&sdev->event_work);
+
+        list_for_each_safe(this, tmp, &sdev->event_list) {
+                struct scsi_event *evt;
+
+                evt = list_entry(this, struct scsi_event, node);
+                list_del(&evt->node);
+                kfree(evt);
+        }
+
         if (sdev->request_queue) {
                 sdev->request_queue->queuedata = NULL;
                 /* user context needed to free queue */
@@ -614,6 +625,41 @@ sdev_show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
 }
 static DEVICE_ATTR(modalias, S_IRUGO, sdev_show_modalias, NULL);
 
+#define DECLARE_EVT_SHOW(name, Cap_name)                                \
+static ssize_t                                                          \
+sdev_show_evt_##name(struct device *dev, struct device_attribute *attr, \
+                                char *buf)                              \
+{                                                                       \
+        struct scsi_device *sdev = to_scsi_device(dev);                 \
+        int val = test_bit(SDEV_EVT_##Cap_name, sdev->supported_events);\
+        return snprintf(buf, 20, "%d\n", val);                          \
+}
+
+#define DECLARE_EVT_STORE(name, Cap_name)                               \
+static ssize_t                                                          \
+sdev_store_evt_##name(struct device *dev, struct device_attribute *attr, \
+                      const char *buf, size_t count)                    \
+{                                                                       \
+        struct scsi_device *sdev = to_scsi_device(dev);                 \
+        int val = simple_strtoul(buf, NULL, 0);                         \
+        if (val == 0)                                                   \
+                clear_bit(SDEV_EVT_##Cap_name, sdev->supported_events); \
+        else if (val == 1)                                              \
+                set_bit(SDEV_EVT_##Cap_name, sdev->supported_events);   \
+        else                                                            \
+                return -EINVAL;                                         \
+        return count;                                                   \
+}
+
+#define DECLARE_EVT(name, Cap_name)                                     \
+        DECLARE_EVT_SHOW(name, Cap_name)                                \
+        DECLARE_EVT_STORE(name, Cap_name)                               \
+        static DEVICE_ATTR(evt_##name, S_IRUGO, sdev_show_evt_##name,   \
+                           sdev_store_evt_##name);
+#define REF_EVT(name) &dev_attr_evt_##name.attr
+
+DECLARE_EVT(media_change, MEDIA_CHANGE)
+
 /* Default template for device attributes.  May NOT be modified */
 static struct attribute *scsi_sdev_attrs[] = {
         &dev_attr_device_blocked.attr,
@@ -631,6 +677,7 @@ static struct attribute *scsi_sdev_attrs[] = {
         &dev_attr_iodone_cnt.attr,
         &dev_attr_ioerr_cnt.attr,
         &dev_attr_modalias.attr,
+        REF_EVT(media_change),
         NULL
 };