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[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>
This commit is contained in:
Hannes Reinecke
committed by
James Bottomley
James Bottomley
parent
6d49f63b41
commit
765cbc6dad
@@ -33,7 +33,7 @@ static struct scsi_device_handler *get_device_handler(const char *name)
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spin_lock(&list_lock);
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list_for_each_entry(tmp, &scsi_dh_list, list) {
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if (!strcmp(tmp->name, name)) {
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if (!strncmp(tmp->name, name, strlen(tmp->name))) {
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found = tmp;
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break;
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}
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@@ -42,11 +42,147 @@ static struct scsi_device_handler *get_device_handler(const char *name)
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return found;
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}
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static int device_handler_match(struct scsi_device_handler *tmp,
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struct scsi_device *sdev)
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{
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int i;
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for(i = 0; tmp->devlist[i].vendor; i++) {
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if (!strncmp(sdev->vendor, tmp->devlist[i].vendor,
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strlen(tmp->devlist[i].vendor)) &&
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!strncmp(sdev->model, tmp->devlist[i].model,
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strlen(tmp->devlist[i].model))) {
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return 1;
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}
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}
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return 0;
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}
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/*
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* scsi_dh_handler_attach - Attach a device handler to a device
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* @sdev - SCSI device the device handler should attach to
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* @scsi_dh - The device handler to attach
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*/
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static int scsi_dh_handler_attach(struct scsi_device *sdev,
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struct scsi_device_handler *scsi_dh)
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{
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int err = 0;
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if (sdev->scsi_dh_data) {
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if (sdev->scsi_dh_data->scsi_dh != scsi_dh)
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err = -EBUSY;
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} else if (scsi_dh->attach)
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err = scsi_dh->attach(sdev);
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return err;
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}
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/*
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* scsi_dh_handler_detach - Detach a device handler from a device
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* @sdev - SCSI device the device handler should be detached from
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* @scsi_dh - Device handler to be detached
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*
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* Detach from a device handler. If a device handler is specified,
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* only detach if the currently attached handler is equal to it.
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*/
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static void scsi_dh_handler_detach(struct scsi_device *sdev,
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struct scsi_device_handler *scsi_dh)
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{
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if (!sdev->scsi_dh_data)
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return;
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if (scsi_dh && scsi_dh != sdev->scsi_dh_data->scsi_dh)
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return;
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if (!scsi_dh)
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scsi_dh = sdev->scsi_dh_data->scsi_dh;
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if (scsi_dh && scsi_dh->detach)
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scsi_dh->detach(sdev);
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}
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/*
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* scsi_dh_notifier - notifier chain callback
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*/
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static int scsi_dh_notifier(struct notifier_block *nb,
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unsigned long action, void *data)
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{
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struct device *dev = data;
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struct scsi_device *sdev;
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int err = 0;
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struct scsi_device_handler *tmp, *devinfo = NULL;
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if (!scsi_is_sdev_device(dev))
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return 0;
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sdev = to_scsi_device(dev);
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spin_lock(&list_lock);
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list_for_each_entry(tmp, &scsi_dh_list, list) {
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if (device_handler_match(tmp, sdev)) {
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devinfo = tmp;
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break;
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}
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}
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spin_unlock(&list_lock);
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if (!devinfo)
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goto out;
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if (action == BUS_NOTIFY_ADD_DEVICE) {
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err = scsi_dh_handler_attach(sdev, devinfo);
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} else if (action == BUS_NOTIFY_DEL_DEVICE) {
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scsi_dh_handler_detach(sdev, NULL);
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}
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out:
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return err;
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}
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/*
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* scsi_dh_notifier_add - Callback for scsi_register_device_handler
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*/
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static int scsi_dh_notifier_add(struct device *dev, void *data)
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{
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struct scsi_device_handler *scsi_dh = data;
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struct scsi_device *sdev;
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if (!scsi_is_sdev_device(dev))
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return 0;
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if (!get_device(dev))
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return 0;
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sdev = to_scsi_device(dev);
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if (device_handler_match(scsi_dh, sdev))
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scsi_dh_handler_attach(sdev, scsi_dh);
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put_device(dev);
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return 0;
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}
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/*
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* scsi_dh_notifier_remove - Callback for scsi_unregister_device_handler
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*/
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static int scsi_dh_notifier_remove(struct device *dev, void *data)
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{
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struct scsi_device_handler *scsi_dh = data;
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struct scsi_device *sdev;
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if (!scsi_is_sdev_device(dev))
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return 0;
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if (!get_device(dev))
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return 0;
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sdev = to_scsi_device(dev);
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scsi_dh_handler_detach(sdev, scsi_dh);
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put_device(dev);
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scsi_dh->nb.notifier_call(&scsi_dh->nb, BUS_NOTIFY_ADD_DEVICE, dev);
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return 0;
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}
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@@ -59,33 +195,19 @@ static int scsi_dh_notifier_add(struct device *dev, void *data)
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*/
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int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
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{
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int ret = -EBUSY;
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struct scsi_device_handler *tmp;
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if (get_device_handler(scsi_dh->name))
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return -EBUSY;
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tmp = get_device_handler(scsi_dh->name);
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if (tmp)
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goto done;
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ret = bus_register_notifier(&scsi_bus_type, &scsi_dh->nb);
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bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, scsi_dh_notifier_add);
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spin_lock(&list_lock);
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list_add(&scsi_dh->list, &scsi_dh_list);
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spin_unlock(&list_lock);
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bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, scsi_dh_notifier_add);
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printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name);
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done:
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return ret;
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return SCSI_DH_OK;
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}
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EXPORT_SYMBOL_GPL(scsi_register_device_handler);
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static int scsi_dh_notifier_remove(struct device *dev, void *data)
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{
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struct scsi_device_handler *scsi_dh = data;
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scsi_dh->nb.notifier_call(&scsi_dh->nb, BUS_NOTIFY_DEL_DEVICE, dev);
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return 0;
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}
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/*
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* scsi_unregister_device_handler - register a device handler personality
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* module.
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@@ -95,23 +217,18 @@ static int scsi_dh_notifier_remove(struct device *dev, void *data)
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*/
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int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh)
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{
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int ret = -ENODEV;
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struct scsi_device_handler *tmp;
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tmp = get_device_handler(scsi_dh->name);
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if (!tmp)
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goto done;
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ret = bus_unregister_notifier(&scsi_bus_type, &scsi_dh->nb);
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if (!get_device_handler(scsi_dh->name))
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return -ENODEV;
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bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh,
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scsi_dh_notifier_remove);
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scsi_dh_notifier_remove);
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spin_lock(&list_lock);
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list_del(&scsi_dh->list);
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spin_unlock(&list_lock);
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printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name);
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done:
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return ret;
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return SCSI_DH_OK;
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}
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EXPORT_SYMBOL_GPL(scsi_unregister_device_handler);
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@@ -157,6 +274,27 @@ int scsi_dh_handler_exist(const char *name)
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}
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EXPORT_SYMBOL_GPL(scsi_dh_handler_exist);
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static struct notifier_block scsi_dh_nb = {
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.notifier_call = scsi_dh_notifier
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};
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static int __init scsi_dh_init(void)
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{
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int r;
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r = bus_register_notifier(&scsi_bus_type, &scsi_dh_nb);
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return r;
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}
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static void __exit scsi_dh_exit(void)
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{
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bus_unregister_notifier(&scsi_bus_type, &scsi_dh_nb);
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}
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module_init(scsi_dh_init);
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module_exit(scsi_dh_exit);
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MODULE_DESCRIPTION("SCSI device handler");
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MODULE_AUTHOR("Chandra Seetharaman <sekharan@us.ibm.com>");
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MODULE_LICENSE("GPL");
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