1 files changed, 62 insertions, 10 deletions

diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c
index 0119b8147797..23149b9e297c 100644
--- a/drivers/scsi/device_handler/scsi_dh.c
+++ b/drivers/scsi/device_handler/scsi_dh.c
@@ -22,6 +22,7 @@
  */
 
 #include <linux/slab.h>
+#include <linux/module.h>
 #include <scsi/scsi_dh.h>
 #include "../scsi_priv.h"
 
@@ -60,6 +61,46 @@ static struct scsi_device_handler *get_device_handler_by_idx(int idx)
 }
 
 /*
+ * device_handler_match_function - Match a device handler to a device
+ * @sdev - SCSI device to be tested
+ *
+ * Tests @sdev against the match function of all registered device_handler.
+ * Returns the found device handler or NULL if not found.
+ */
+static struct scsi_device_handler *
+device_handler_match_function(struct scsi_device *sdev)
+{
+        struct scsi_device_handler *tmp_dh, *found_dh = NULL;
+
+        spin_lock(&list_lock);
+        list_for_each_entry(tmp_dh, &scsi_dh_list, list) {
+                if (tmp_dh->match && tmp_dh->match(sdev)) {
+                        found_dh = tmp_dh;
+                        break;
+                }
+        }
+        spin_unlock(&list_lock);
+        return found_dh;
+}
+
+/*
+ * device_handler_match_devlist - Match a device handler to a device
+ * @sdev - SCSI device to be tested
+ *
+ * Tests @sdev against all device_handler registered in the devlist.
+ * Returns the found device handler or NULL if not found.
+ */
+static struct scsi_device_handler *
+device_handler_match_devlist(struct scsi_device *sdev)
+{
+        int idx;
+
+        idx = scsi_get_device_flags_keyed(sdev, sdev->vendor, sdev->model,
+                                          SCSI_DEVINFO_DH);
+        return get_device_handler_by_idx(idx);
+}
+
+/*
  * device_handler_match - Attach a device handler to a device
  * @scsi_dh - The device handler to match against or NULL
  * @sdev - SCSI device to be tested against @scsi_dh
@@ -72,12 +113,11 @@ static struct scsi_device_handler *
 device_handler_match(struct scsi_device_handler *scsi_dh,
                      struct scsi_device *sdev)
 {
-        struct scsi_device_handler *found_dh = NULL;
-        int idx;
+        struct scsi_device_handler *found_dh;
 
-        idx = scsi_get_device_flags_keyed(sdev, sdev->vendor, sdev->model,
-                                          SCSI_DEVINFO_DH);
-        found_dh = get_device_handler_by_idx(idx);
+        found_dh = device_handler_match_function(sdev);
+        if (!found_dh)
+                found_dh = device_handler_match_devlist(sdev);
 
         if (scsi_dh && found_dh != scsi_dh)
                 found_dh = NULL;
@@ -151,6 +191,10 @@ store_dh_state(struct device *dev, struct device_attribute *attr,
         struct scsi_device_handler *scsi_dh;
         int err = -EINVAL;
 
+        if (sdev->sdev_state == SDEV_CANCEL ||
+            sdev->sdev_state == SDEV_DEL)
+                return -ENODEV;
+
         if (!sdev->scsi_dh_data) {
                 /*
                  * Attach to a device handler
@@ -327,7 +371,7 @@ int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
         list_add(&scsi_dh->list, &scsi_dh_list);
         spin_unlock(&list_lock);
 
-        for (i = 0; scsi_dh->devlist[i].vendor; i++) {
+        for (i = 0; scsi_dh->devlist && scsi_dh->devlist[i].vendor; i++) {
                 scsi_dev_info_list_add_keyed(0,
                                         scsi_dh->devlist[i].vendor,
                                         scsi_dh->devlist[i].model,
@@ -360,7 +404,7 @@ int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh)
         bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh,
                          scsi_dh_notifier_remove);
 
-        for (i = 0; scsi_dh->devlist[i].vendor; i++) {
+        for (i = 0; scsi_dh->devlist && scsi_dh->devlist[i].vendor; i++) {
                 scsi_dev_info_list_del_keyed(scsi_dh->devlist[i].vendor,
                                              scsi_dh->devlist[i].model,
                                              SCSI_DEVINFO_DH);
@@ -398,7 +442,15 @@ int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data)
 
         spin_lock_irqsave(q->queue_lock, flags);
         sdev = q->queuedata;
-        if (sdev && sdev->scsi_dh_data)
+        if (!sdev) {
+                spin_unlock_irqrestore(q->queue_lock, flags);
+                err = SCSI_DH_NOSYS;
+                if (fn)
+                        fn(data, err);
+                return err;
+        }
+
+        if (sdev->scsi_dh_data)
                 scsi_dh = sdev->scsi_dh_data->scsi_dh;
         dev = get_device(&sdev->sdev_gendev);
         if (!scsi_dh || !dev ||
@@ -468,7 +520,7 @@ int scsi_dh_handler_exist(const char *name)
 EXPORT_SYMBOL_GPL(scsi_dh_handler_exist);
 
 /*
- * scsi_dh_handler_attach - Attach device handler
+ * scsi_dh_attach - Attach device handler
  * @sdev - sdev the handler should be attached to
  * @name - name of the handler to attach
  */
@@ -498,7 +550,7 @@ int scsi_dh_attach(struct request_queue *q, const char *name)
 EXPORT_SYMBOL_GPL(scsi_dh_attach);
 
 /*
- * scsi_dh_handler_detach - Detach device handler
+ * scsi_dh_detach - Detach device handler
  * @sdev - sdev the handler should be detached from
  *
  * This function will detach the device handler only