[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>

5 files changed, 296 insertions, 219 deletions

diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c
index ab6c21cd9689..3f798171ed69 100644
--- a/drivers/scsi/device_handler/scsi_dh.c
+++ b/drivers/scsi/device_handler/scsi_dh.c
@@ -33,7 +33,7 @@ static struct scsi_device_handler *get_device_handler(const char *name)
 
         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;
                 }
@@ -42,51 +42,173 @@ static struct scsi_device_handler *get_device_handler(const char *name)
         return found;
 }
 
-static int scsi_dh_notifier_add(struct device *dev, void *data)
+static int device_handler_match(struct scsi_device_handler *tmp,
+                                struct scsi_device *sdev)
 {
-        struct scsi_device_handler *scsi_dh = data;
+        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;
+                }
+        }
 
-        scsi_dh->nb.notifier_call(&scsi_dh->nb, BUS_NOTIFY_ADD_DEVICE, dev);
         return 0;
 }
 
 /*
- * scsi_register_device_handler - register a device handler personality
- *      module.
- * @scsi_dh - device handler to be registered.
+ * 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
  *
- * Returns 0 on success, -EBUSY if handler already registered.
+ * Detach from a device handler. If a device handler is specified,
+ * only detach if the currently attached handler is equal to it.
  */
-int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
+static void scsi_dh_handler_detach(struct scsi_device *sdev,
+                                   struct scsi_device_handler *scsi_dh)
 {
-        int ret = -EBUSY;
-        struct scsi_device_handler *tmp;
+        if (!sdev->scsi_dh_data)
+                return;
 
-        tmp = get_device_handler(scsi_dh->name);
-        if (tmp)
-                goto done;
+        if (scsi_dh && scsi_dh != sdev->scsi_dh_data->scsi_dh)
+                return;
 
-        ret = bus_register_notifier(&scsi_bus_type, &scsi_dh->nb);
+        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);
 
-        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);
+        list_for_each_entry(tmp, &scsi_dh_list, list) {
+                if (device_handler_match(tmp, sdev)) {
+                        devinfo = tmp;
+                        break;
+                }
+        }
         spin_unlock(&list_lock);
 
-done:
-        return ret;
+        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;
 }
-EXPORT_SYMBOL_GPL(scsi_register_device_handler);
 
+/*
+ * 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;
+
+        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);
 
-        scsi_dh->nb.notifier_call(&scsi_dh->nb, BUS_NOTIFY_DEL_DEVICE, dev);
         return 0;
 }
 
 /*
+ * scsi_register_device_handler - register a device handler personality
+ *      module.
+ * @scsi_dh - device handler to be registered.
+ *
+ * Returns 0 on success, -EBUSY if handler already registered.
+ */
+int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
+{
+        if (get_device_handler(scsi_dh->name))
+                return -EBUSY;
+
+        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);
+
+        return SCSI_DH_OK;
+}
+EXPORT_SYMBOL_GPL(scsi_register_device_handler);
+
+/*
  * scsi_unregister_device_handler - register a device handler personality
  *      module.
  * @scsi_dh - device handler to be unregistered.
@@ -95,23 +217,18 @@ static int scsi_dh_notifier_remove(struct device *dev, void *data)
  */
 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 @@ int scsi_dh_handler_exist(const char *name)
 }
 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");
diff --git a/drivers/scsi/device_handler/scsi_dh_emc.c b/drivers/scsi/device_handler/scsi_dh_emc.c
index f2467e936e55..bf0a389c52d8 100644
--- a/drivers/scsi/device_handler/scsi_dh_emc.c
+++ b/drivers/scsi/device_handler/scsi_dh_emc.c
@@ -238,12 +238,12 @@ done:
 }
 
 /*
-* Get block request for REQ_BLOCK_PC command issued to path.  Currently
-* limited to MODE_SELECT (trespass) and INQUIRY (VPD page 0xC0) commands.
-*
-* Uses data and sense buffers in hardware handler context structure and
-* assumes serial servicing of commands, both issuance and completion.
-*/
+ * Get block request for REQ_BLOCK_PC command issued to path.  Currently
+ * limited to MODE_SELECT (trespass) and INQUIRY (VPD page 0xC0) commands.
+ *
+ * Uses data and sense buffers in hardware handler context structure and
+ * assumes serial servicing of commands, both issuance and completion.
+ */
 static struct request *get_req(struct scsi_device *sdev, int cmd)
 {
         struct clariion_dh_data *csdev = get_clariion_data(sdev);
@@ -390,21 +390,21 @@ static int clariion_check_sense(struct scsi_device *sdev,
         return SUCCESS;
 }
 
-static const struct {
-        char *vendor;
-        char *model;
-} clariion_dev_list[] = {
+const struct scsi_dh_devlist clariion_dev_list[] = {
         {"DGC", "RAID"},
         {"DGC", "DISK"},
         {NULL, NULL},
 };
 
-static int clariion_bus_notify(struct notifier_block *, unsigned long, void *);
+static int clariion_bus_attach(struct scsi_device *sdev);
+static void clariion_bus_detach(struct scsi_device *sdev);
 
 static struct scsi_device_handler clariion_dh = {
         .name           = CLARIION_NAME,
         .module         = THIS_MODULE,
-        .nb.notifier_call = clariion_bus_notify,
+        .devlist        = clariion_dev_list,
+        .attach         = clariion_bus_attach,
+        .detach         = clariion_bus_detach,
         .check_sense    = clariion_check_sense,
         .activate       = clariion_activate,
 };
@@ -412,73 +412,50 @@ static struct scsi_device_handler clariion_dh = {
 /*
  * TODO: need some interface so we can set trespass values
  */
-static int clariion_bus_notify(struct notifier_block *nb,
-                                unsigned long action, void *data)
+static int clariion_bus_attach(struct scsi_device *sdev)
 {
-        struct device *dev = data;
-        struct scsi_device *sdev;
         struct scsi_dh_data *scsi_dh_data;
         struct clariion_dh_data *h;
-        int i, found = 0;
         unsigned long flags;
 
-        if (!scsi_is_sdev_device(dev))
-                return 0;
-
-        sdev = to_scsi_device(dev);
-
-        if (action == BUS_NOTIFY_ADD_DEVICE) {
-                for (i = 0; clariion_dev_list[i].vendor; i++) {
-                        if (!strncmp(sdev->vendor, clariion_dev_list[i].vendor,
-                                     strlen(clariion_dev_list[i].vendor)) &&
-                            !strncmp(sdev->model, clariion_dev_list[i].model,
-                                     strlen(clariion_dev_list[i].model))) {
-                                found = 1;
-                                break;
-                        }
-                }
-                if (!found)
-                        goto out;
-
-                scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
-                                + sizeof(*h) , GFP_KERNEL);
-                if (!scsi_dh_data) {
-                        sdev_printk(KERN_ERR, sdev, "Attach failed %s.\n",
-                                    CLARIION_NAME);
-                        goto out;
-                }
+        scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
+                               + sizeof(*h) , GFP_KERNEL);
+        if (!scsi_dh_data) {
+                sdev_printk(KERN_ERR, sdev, "Attach failed %s.\n",
+                            CLARIION_NAME);
+                return -ENOMEM;
+        }
 
-                scsi_dh_data->scsi_dh = &clariion_dh;
-                h = (struct clariion_dh_data *) scsi_dh_data->buf;
-                h->default_sp = CLARIION_UNBOUND_LU;
-                h->current_sp = CLARIION_UNBOUND_LU;
+        scsi_dh_data->scsi_dh = &clariion_dh;
+        h = (struct clariion_dh_data *) scsi_dh_data->buf;
+        h->default_sp = CLARIION_UNBOUND_LU;
+        h->current_sp = CLARIION_UNBOUND_LU;
 
-                spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
-                sdev->scsi_dh_data = scsi_dh_data;
-                spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
+        spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
+        sdev->scsi_dh_data = scsi_dh_data;
+        spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
 
-                sdev_printk(KERN_NOTICE, sdev, "Attached %s.\n", CLARIION_NAME);
-                try_module_get(THIS_MODULE);
+        sdev_printk(KERN_NOTICE, sdev, "Attached %s.\n", CLARIION_NAME);
+        try_module_get(THIS_MODULE);
 
-        } else if (action == BUS_NOTIFY_DEL_DEVICE) {
-                if (sdev->scsi_dh_data == NULL ||
-                                sdev->scsi_dh_data->scsi_dh != &clariion_dh)
-                        goto out;
+        return 0;
+}
 
-                spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
-                scsi_dh_data = sdev->scsi_dh_data;
-                sdev->scsi_dh_data = NULL;
-                spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
+static void clariion_bus_detach(struct scsi_device *sdev)
+{
+        struct scsi_dh_data *scsi_dh_data;
+        unsigned long flags;
 
-                sdev_printk(KERN_NOTICE, sdev, "Dettached %s.\n",
-                            CLARIION_NAME);
+        spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
+        scsi_dh_data = sdev->scsi_dh_data;
+        sdev->scsi_dh_data = NULL;
+        spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
 
-                kfree(scsi_dh_data);
-                module_put(THIS_MODULE);
-        }
+        sdev_printk(KERN_NOTICE, sdev, "Detached %s.\n",
+                    CLARIION_NAME);
 
-out:
-        return 0;
+        kfree(scsi_dh_data);
+        module_put(THIS_MODULE);
 }
 
 static int __init clariion_init(void)
diff --git a/drivers/scsi/device_handler/scsi_dh_hp_sw.c b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
index ae6be87d6a83..78259bc5dfc9 100644
--- a/drivers/scsi/device_handler/scsi_dh_hp_sw.c
+++ b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
@@ -108,85 +108,63 @@ done:
         return ret;
 }
 
-static const struct {
-        char *vendor;
-        char *model;
-} hp_sw_dh_data_list[] = {
+const struct scsi_dh_devlist hp_sw_dh_data_list[] = {
         {"COMPAQ", "MSA"},
         {"HP", "HSV"},
         {"DEC", "HSG80"},
         {NULL, NULL},
 };
 
-static int hp_sw_bus_notify(struct notifier_block *, unsigned long, void *);
+static int hp_sw_bus_attach(struct scsi_device *sdev);
+static void hp_sw_bus_detach(struct scsi_device *sdev);
 
 static struct scsi_device_handler hp_sw_dh = {
         .name           = HP_SW_NAME,
         .module         = THIS_MODULE,
-        .nb.notifier_call = hp_sw_bus_notify,
+        .devlist        = hp_sw_dh_data_list,
+        .attach         = hp_sw_bus_attach,
+        .detach         = hp_sw_bus_detach,
         .activate       = hp_sw_activate,
 };
 
-static int hp_sw_bus_notify(struct notifier_block *nb,
-                            unsigned long action, void *data)
+static int hp_sw_bus_attach(struct scsi_device *sdev)
 {
-        struct device *dev = data;
-        struct scsi_device *sdev;
         struct scsi_dh_data *scsi_dh_data;
-        int i, found = 0;
         unsigned long flags;
 
-        if (!scsi_is_sdev_device(dev))
+        scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
+                               + sizeof(struct hp_sw_dh_data) , GFP_KERNEL);
+        if (!scsi_dh_data) {
+                sdev_printk(KERN_ERR, sdev, "Attach Failed %s.\n",
+                            HP_SW_NAME);
                 return 0;
+        }
 
-        sdev = to_scsi_device(dev);
-
-        if (action == BUS_NOTIFY_ADD_DEVICE) {
-                for (i = 0; hp_sw_dh_data_list[i].vendor; i++) {
-                        if (!strncmp(sdev->vendor, hp_sw_dh_data_list[i].vendor,
-                                     strlen(hp_sw_dh_data_list[i].vendor)) &&
-                            !strncmp(sdev->model, hp_sw_dh_data_list[i].model,
-                                     strlen(hp_sw_dh_data_list[i].model))) {
-                                found = 1;
-                                break;
-                        }
-                }
-                if (!found)
-                        goto out;
-
-                scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
-                                + sizeof(struct hp_sw_dh_data) , GFP_KERNEL);
-                if (!scsi_dh_data) {
-                        sdev_printk(KERN_ERR, sdev, "Attach Failed %s.\n",
-                                    HP_SW_NAME);
-                        goto out;
-                }
+        scsi_dh_data->scsi_dh = &hp_sw_dh;
+        spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
+        sdev->scsi_dh_data = scsi_dh_data;
+        spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
+        try_module_get(THIS_MODULE);
 
-                scsi_dh_data->scsi_dh = &hp_sw_dh;
-                spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
-                sdev->scsi_dh_data = scsi_dh_data;
-                spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
-                try_module_get(THIS_MODULE);
+        sdev_printk(KERN_NOTICE, sdev, "Attached %s.\n", HP_SW_NAME);
 
-                sdev_printk(KERN_NOTICE, sdev, "Attached %s.\n", HP_SW_NAME);
-        } else if (action == BUS_NOTIFY_DEL_DEVICE) {
-                if (sdev->scsi_dh_data == NULL ||
-                                sdev->scsi_dh_data->scsi_dh != &hp_sw_dh)
-                        goto out;
+        return 0;
+}
 
-                spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
-                scsi_dh_data = sdev->scsi_dh_data;
-                sdev->scsi_dh_data = NULL;
-                spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
-                module_put(THIS_MODULE);
+static void hp_sw_bus_detach( struct scsi_device *sdev )
+{
+        struct scsi_dh_data *scsi_dh_data;
+        unsigned long flags;
 
-                sdev_printk(KERN_NOTICE, sdev, "Dettached %s.\n", HP_SW_NAME);
+        spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
+        scsi_dh_data = sdev->scsi_dh_data;
+        sdev->scsi_dh_data = NULL;
+        spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
+        module_put(THIS_MODULE);
 
-                kfree(scsi_dh_data);
-        }
+        sdev_printk(KERN_NOTICE, sdev, "Detached %s\n", HP_SW_NAME);
 
-out:
-        return 0;
+        kfree(scsi_dh_data);
 }
 
 static int __init hp_sw_init(void)
diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c
index fdf34b0ec6e1..0e25a6e9c82d 100644
--- a/drivers/scsi/device_handler/scsi_dh_rdac.c
+++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
@@ -569,10 +569,7 @@ static int rdac_check_sense(struct scsi_device *sdev,
         return SCSI_RETURN_NOT_HANDLED;
 }
 
-static const struct {
-        char *vendor;
-        char *model;
-} rdac_dev_list[] = {
+const struct scsi_dh_devlist rdac_dev_list[] = {
         {"IBM", "1722"},
         {"IBM", "1724"},
         {"IBM", "1726"},
@@ -590,89 +587,69 @@ static const struct {
         {NULL, NULL},
 };
 
-static int rdac_bus_notify(struct notifier_block *, unsigned long, void *);
+static int rdac_bus_attach(struct scsi_device *sdev);
+static void rdac_bus_detach(struct scsi_device *sdev);
 
 static struct scsi_device_handler rdac_dh = {
         .name = RDAC_NAME,
         .module = THIS_MODULE,
-        .nb.notifier_call = rdac_bus_notify,
+        .devlist = rdac_dev_list,
         .prep_fn = rdac_prep_fn,
         .check_sense = rdac_check_sense,
+        .attach = rdac_bus_attach,
+        .detach = rdac_bus_detach,
         .activate = rdac_activate,
 };
 
-/*
- * TODO: need some interface so we can set trespass values
- */
-static int rdac_bus_notify(struct notifier_block *nb,
-                            unsigned long action, void *data)
+static int rdac_bus_attach(struct scsi_device *sdev)
 {
-        struct device *dev = data;
-        struct scsi_device *sdev;
         struct scsi_dh_data *scsi_dh_data;
         struct rdac_dh_data *h;
-        int i, found = 0;
         unsigned long flags;
 
-        if (!scsi_is_sdev_device(dev))
+        scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
+                               + sizeof(*h) , GFP_KERNEL);
+        if (!scsi_dh_data) {
+                sdev_printk(KERN_ERR, sdev, "Attach failed %s.\n",
+                            RDAC_NAME);
                 return 0;
+        }
 
-        sdev = to_scsi_device(dev);
-
-        if (action == BUS_NOTIFY_ADD_DEVICE) {
-                for (i = 0; rdac_dev_list[i].vendor; i++) {
-                        if (!strncmp(sdev->vendor, rdac_dev_list[i].vendor,
-                                     strlen(rdac_dev_list[i].vendor)) &&
-                            !strncmp(sdev->model, rdac_dev_list[i].model,
-                                     strlen(rdac_dev_list[i].model))) {
-                                found = 1;
-                                break;
-                        }
-                }
-                if (!found)
-                        goto out;
-
-                scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
-                                + sizeof(*h) , GFP_KERNEL);
-                if (!scsi_dh_data) {
-                        sdev_printk(KERN_ERR, sdev, "Attach failed %s.\n",
-                                    RDAC_NAME);
-                        goto out;
-                }
+        scsi_dh_data->scsi_dh = &rdac_dh;
+        h = (struct rdac_dh_data *) scsi_dh_data->buf;
+        h->lun = UNINITIALIZED_LUN;
+        h->state = RDAC_STATE_ACTIVE;
+        spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
+        sdev->scsi_dh_data = scsi_dh_data;
+        spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
+        try_module_get(THIS_MODULE);
 
-                scsi_dh_data->scsi_dh = &rdac_dh;
-                h = (struct rdac_dh_data *) scsi_dh_data->buf;
-                h->lun = UNINITIALIZED_LUN;
-                h->state = RDAC_STATE_ACTIVE;
-                spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
-                sdev->scsi_dh_data = scsi_dh_data;
-                spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
-                try_module_get(THIS_MODULE);
-
-                sdev_printk(KERN_NOTICE, sdev, "Attached %s.\n", RDAC_NAME);
-
-        } else if (action == BUS_NOTIFY_DEL_DEVICE) {
-                if (sdev->scsi_dh_data == NULL ||
-                                sdev->scsi_dh_data->scsi_dh != &rdac_dh)
-                        goto out;
-
-                spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
-                scsi_dh_data = sdev->scsi_dh_data;
-                sdev->scsi_dh_data = NULL;
-                spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
-
-                h = (struct rdac_dh_data *) scsi_dh_data->buf;
-                if (h->ctlr)
-                        kref_put(&h->ctlr->kref, release_controller);
-                kfree(scsi_dh_data);
-                module_put(THIS_MODULE);
-                sdev_printk(KERN_NOTICE, sdev, "Dettached %s.\n", RDAC_NAME);
-        }
+        sdev_printk(KERN_NOTICE, sdev, "Attached %s\n", RDAC_NAME);
 
-out:
         return 0;
 }
 
+static void rdac_bus_detach( struct scsi_device *sdev )
+{
+        struct scsi_dh_data *scsi_dh_data;
+        struct rdac_dh_data *h;
+        unsigned long flags;
+
+        spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
+        scsi_dh_data = sdev->scsi_dh_data;
+        sdev->scsi_dh_data = NULL;
+        spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
+
+        h = (struct rdac_dh_data *) scsi_dh_data->buf;
+        if (h->ctlr)
+                kref_put(&h->ctlr->kref, release_controller);
+        kfree(scsi_dh_data);
+        module_put(THIS_MODULE);
+        sdev_printk(KERN_NOTICE, sdev, "Detached %s\n", RDAC_NAME);
+}
+
+
+
 static int __init rdac_init(void)
 {
         int r;
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 6467f78b191f..4deb9349eebf 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -167,15 +167,22 @@ struct scsi_device {
         unsigned long           sdev_data[0];
 } __attribute__((aligned(sizeof(unsigned long))));
 
+struct scsi_dh_devlist {
+        char *vendor;
+        char *model;
+};
+
 struct scsi_device_handler {
         /* Used by the infrastructure */
         struct list_head list; /* list of scsi_device_handlers */
-        struct notifier_block nb;
 
         /* Filled by the hardware handler */
         struct module *module;
         const char *name;
+        const struct scsi_dh_devlist *devlist;
         int (*check_sense)(struct scsi_device *, struct scsi_sense_hdr *);
+        int (*attach)(struct scsi_device *);
+        void (*detach)(struct scsi_device *);
         int (*activate)(struct scsi_device *);
         int (*prep_fn)(struct scsi_device *, struct request *);
 };