[SCSI] scsi_dh: Implement common device table handling
Instead of having each and every driver implement its own
device table scanning code we should rather implement a common
routine and scan the device tables there.
This allows us also to implement a general notifier chain
callback for all device handler instead for one per handler.
[sekharan: Fix rejections caused by conflicting bug fix]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c
index ab6c21c..3f79817 100644
--- a/drivers/scsi/device_handler/scsi_dh.c
+++ b/drivers/scsi/device_handler/scsi_dh.c
@@ -33,7 +33,7 @@
spin_lock(&list_lock);
list_for_each_entry(tmp, &scsi_dh_list, list) {
- if (!strcmp(tmp->name, name)) {
+ if (!strncmp(tmp->name, name, strlen(tmp->name))) {
found = tmp;
break;
}
@@ -42,11 +42,147 @@
return found;
}
+static int device_handler_match(struct scsi_device_handler *tmp,
+ struct scsi_device *sdev)
+{
+ int i;
+
+ for(i = 0; tmp->devlist[i].vendor; i++) {
+ if (!strncmp(sdev->vendor, tmp->devlist[i].vendor,
+ strlen(tmp->devlist[i].vendor)) &&
+ !strncmp(sdev->model, tmp->devlist[i].model,
+ strlen(tmp->devlist[i].model))) {
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * scsi_dh_handler_attach - Attach a device handler to a device
+ * @sdev - SCSI device the device handler should attach to
+ * @scsi_dh - The device handler to attach
+ */
+static int scsi_dh_handler_attach(struct scsi_device *sdev,
+ struct scsi_device_handler *scsi_dh)
+{
+ int err = 0;
+
+ if (sdev->scsi_dh_data) {
+ if (sdev->scsi_dh_data->scsi_dh != scsi_dh)
+ err = -EBUSY;
+ } else if (scsi_dh->attach)
+ err = scsi_dh->attach(sdev);
+
+ return err;
+}
+
+/*
+ * scsi_dh_handler_detach - Detach a device handler from a device
+ * @sdev - SCSI device the device handler should be detached from
+ * @scsi_dh - Device handler to be detached
+ *
+ * Detach from a device handler. If a device handler is specified,
+ * only detach if the currently attached handler is equal to it.
+ */
+static void scsi_dh_handler_detach(struct scsi_device *sdev,
+ struct scsi_device_handler *scsi_dh)
+{
+ if (!sdev->scsi_dh_data)
+ return;
+
+ if (scsi_dh && scsi_dh != sdev->scsi_dh_data->scsi_dh)
+ return;
+
+ if (!scsi_dh)
+ scsi_dh = sdev->scsi_dh_data->scsi_dh;
+
+ if (scsi_dh && scsi_dh->detach)
+ scsi_dh->detach(sdev);
+}
+
+/*
+ * scsi_dh_notifier - notifier chain callback
+ */
+static int scsi_dh_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct device *dev = data;
+ struct scsi_device *sdev;
+ int err = 0;
+ struct scsi_device_handler *tmp, *devinfo = NULL;
+
+ if (!scsi_is_sdev_device(dev))
+ return 0;
+
+ sdev = to_scsi_device(dev);
+
+ spin_lock(&list_lock);
+ list_for_each_entry(tmp, &scsi_dh_list, list) {
+ if (device_handler_match(tmp, sdev)) {
+ devinfo = tmp;
+ break;
+ }
+ }
+ spin_unlock(&list_lock);
+
+ if (!devinfo)
+ goto out;
+
+ if (action == BUS_NOTIFY_ADD_DEVICE) {
+ err = scsi_dh_handler_attach(sdev, devinfo);
+ } else if (action == BUS_NOTIFY_DEL_DEVICE) {
+ scsi_dh_handler_detach(sdev, NULL);
+ }
+out:
+ return err;
+}
+
+/*
+ * scsi_dh_notifier_add - Callback for scsi_register_device_handler
+ */
static int scsi_dh_notifier_add(struct device *dev, void *data)
{
struct scsi_device_handler *scsi_dh = data;
+ struct scsi_device *sdev;
- scsi_dh->nb.notifier_call(&scsi_dh->nb, BUS_NOTIFY_ADD_DEVICE, dev);
+ if (!scsi_is_sdev_device(dev))
+ return 0;
+
+ if (!get_device(dev))
+ return 0;
+
+ sdev = to_scsi_device(dev);
+
+ if (device_handler_match(scsi_dh, sdev))
+ scsi_dh_handler_attach(sdev, scsi_dh);
+
+ put_device(dev);
+
+ return 0;
+}
+
+/*
+ * scsi_dh_notifier_remove - Callback for scsi_unregister_device_handler
+ */
+static int scsi_dh_notifier_remove(struct device *dev, void *data)
+{
+ struct scsi_device_handler *scsi_dh = data;
+ struct scsi_device *sdev;
+
+ if (!scsi_is_sdev_device(dev))
+ return 0;
+
+ if (!get_device(dev))
+ return 0;
+
+ sdev = to_scsi_device(dev);
+
+ scsi_dh_handler_detach(sdev, scsi_dh);
+
+ put_device(dev);
+
return 0;
}
@@ -59,33 +195,19 @@
*/
int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
{
- int ret = -EBUSY;
- struct scsi_device_handler *tmp;
+ if (get_device_handler(scsi_dh->name))
+ return -EBUSY;
- tmp = get_device_handler(scsi_dh->name);
- if (tmp)
- goto done;
-
- ret = bus_register_notifier(&scsi_bus_type, &scsi_dh->nb);
-
- bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, scsi_dh_notifier_add);
spin_lock(&list_lock);
list_add(&scsi_dh->list, &scsi_dh_list);
spin_unlock(&list_lock);
+ bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, scsi_dh_notifier_add);
+ printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name);
-done:
- return ret;
+ return SCSI_DH_OK;
}
EXPORT_SYMBOL_GPL(scsi_register_device_handler);
-static int scsi_dh_notifier_remove(struct device *dev, void *data)
-{
- struct scsi_device_handler *scsi_dh = data;
-
- scsi_dh->nb.notifier_call(&scsi_dh->nb, BUS_NOTIFY_DEL_DEVICE, dev);
- return 0;
-}
-
/*
* scsi_unregister_device_handler - register a device handler personality
* module.
@@ -95,23 +217,18 @@
*/
int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh)
{
- int ret = -ENODEV;
- struct scsi_device_handler *tmp;
-
- tmp = get_device_handler(scsi_dh->name);
- if (!tmp)
- goto done;
-
- ret = bus_unregister_notifier(&scsi_bus_type, &scsi_dh->nb);
+ if (!get_device_handler(scsi_dh->name))
+ return -ENODEV;
bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh,
- scsi_dh_notifier_remove);
+ scsi_dh_notifier_remove);
+
spin_lock(&list_lock);
list_del(&scsi_dh->list);
spin_unlock(&list_lock);
+ printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name);
-done:
- return ret;
+ return SCSI_DH_OK;
}
EXPORT_SYMBOL_GPL(scsi_unregister_device_handler);
@@ -157,6 +274,27 @@
}
EXPORT_SYMBOL_GPL(scsi_dh_handler_exist);
+static struct notifier_block scsi_dh_nb = {
+ .notifier_call = scsi_dh_notifier
+};
+
+static int __init scsi_dh_init(void)
+{
+ int r;
+
+ r = bus_register_notifier(&scsi_bus_type, &scsi_dh_nb);
+
+ return r;
+}
+
+static void __exit scsi_dh_exit(void)
+{
+ bus_unregister_notifier(&scsi_bus_type, &scsi_dh_nb);
+}
+
+module_init(scsi_dh_init);
+module_exit(scsi_dh_exit);
+
MODULE_DESCRIPTION("SCSI device handler");
MODULE_AUTHOR("Chandra Seetharaman <sekharan@us.ibm.com>");
MODULE_LICENSE("GPL");