2 files changed, 38 insertions, 16 deletions

diff --git a/drivers/misc/enclosure.c b/drivers/misc/enclosure.c
index 348443bdb23b..789d12128c24 100644
--- a/drivers/misc/enclosure.c
+++ b/drivers/misc/enclosure.c
@@ -33,24 +33,44 @@ static DEFINE_MUTEX(container_list_lock);
 static struct class enclosure_class;
 
 /**
- * enclosure_find - find an enclosure given a device
- * @dev:	the device to find for
+ * enclosure_find - find an enclosure given a parent device
+ * @dev:	the parent to match against
+ * @start:	Optional enclosure device to start from (NULL if none)
  *
- * Looks through the list of registered enclosures to see
- * if it can find a match for a device.  Returns NULL if no
- * enclosure is found. Obtains a reference to the enclosure class
- * device which must be released with device_put().
+ * Looks through the list of registered enclosures to find all those
+ * with @dev as a parent.  Returns NULL if no enclosure is
+ * found. @start can be used as a starting point to obtain multiple
+ * enclosures per parent (should begin with NULL and then be set to
+ * each returned enclosure device). Obtains a reference to the
+ * enclosure class device which must be released with device_put().
+ * If @start is not NULL, a reference must be taken on it which is
+ * released before returning (this allows a loop through all
+ * enclosures to exit with only the reference on the enclosure of
+ * interest held).  Note that the @dev may correspond to the actual
+ * device housing the enclosure, in which case no iteration via @start
+ * is required.
  */
-struct enclosure_device *enclosure_find(struct device *dev)
+struct enclosure_device *enclosure_find(struct device *dev,
+					struct enclosure_device *start)
 {
 	struct enclosure_device *edev;
 
 	mutex_lock(&container_list_lock);
-	list_for_each_entry(edev, &container_list, node) {
-		if (edev->edev.parent == dev) {
-			get_device(&edev->edev);
-			mutex_unlock(&container_list_lock);
-			return edev;
+	edev = list_prepare_entry(start, &container_list, node);
+	if (start)
+		put_device(&start->edev);
+
+	list_for_each_entry_continue(edev, &container_list, node) {
+		struct device *parent = edev->edev.parent;
+		/* parent might not be immediate, so iterate up to
+		 * the root of the tree if necessary */
+		while (parent) {
+			if (parent == dev) {
+				get_device(&edev->edev);
+				mutex_unlock(&container_list_lock);
+				return edev;
+			}
+			parent = parent->parent;
 		}
 	}
 	mutex_unlock(&container_list_lock);
diff --git a/drivers/scsi/ses.c b/drivers/scsi/ses.c
index 4f618f487356..e1b8c828f03a 100644
--- a/drivers/scsi/ses.c
+++ b/drivers/scsi/ses.c
@@ -413,10 +413,11 @@ static int ses_intf_add(struct device *cdev,
 
 	if (!scsi_device_enclosure(sdev)) {
 		/* not an enclosure, but might be in one */
-		edev = enclosure_find(&sdev->host->shost_gendev);
-		if (edev) {
+		struct enclosure_device *prev = NULL;
+
+		while ((edev = enclosure_find(&sdev->host->shost_gendev, prev)) != NULL) {
 			ses_match_to_enclosure(edev, sdev);
-			put_device(&edev->edev);
+			prev = edev;
 		}
 		return -ENODEV;
 	}
@@ -625,7 +626,8 @@ static void ses_intf_remove(struct device *cdev,
 	if (!scsi_device_enclosure(sdev))
 		return;
 
-	edev = enclosure_find(cdev->parent);
+	/*  exact match to this enclosure */
+	edev = enclosure_find(cdev->parent, NULL);
 	if (!edev)
 		return;