[SCSI] iscsi_ibft, be2iscsi, iscsi_boot: fix boot kobj data lifetime management

be2iscsi passes the boot functions its phba object which is
allocated in the shost, but iscsi_ibft passes in a object
allocated for each item to display. The problem is that
iscsi_boot_sysfs was managing the lifetime of the object
passed in and doing a kfree on release. This causes a double
free for be2iscsi which frees the shost in its pci_remove.

This patch fixes the problem by adding a release callback
which the drivers can call kfree or a put() type of function
(needed for be2iscsi which will do a get/put on the shost).

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 19 insertions, 9 deletions

diff --git a/drivers/scsi/iscsi_boot_sysfs.c b/drivers/scsi/iscsi_boot_sysfs.c
index 4274ce93d8f2..89700cbca16e 100644
--- a/drivers/scsi/iscsi_boot_sysfs.c
+++ b/drivers/scsi/iscsi_boot_sysfs.c
@@ -64,7 +64,8 @@ static void iscsi_boot_kobj_release(struct kobject *kobj)
 	struct iscsi_boot_kobj *boot_kobj =
 			container_of(kobj, struct iscsi_boot_kobj, kobj);
 
-	kfree(boot_kobj->data);
+	if (boot_kobj->release)
+		boot_kobj->release(boot_kobj->data);
 	kfree(boot_kobj);
 }
 
@@ -305,7 +306,8 @@ iscsi_boot_create_kobj(struct iscsi_boot_kset *boot_kset,
 		       struct attribute_group *attr_group,
 		       const char *name, int index, void *data,
 		       ssize_t (*show) (void *data, int type, char *buf),
-		       mode_t (*is_visible) (void *data, int type))
+		       mode_t (*is_visible) (void *data, int type),
+		       void (*release) (void *data))
 {
 	struct iscsi_boot_kobj *boot_kobj;
 
@@ -323,6 +325,7 @@ iscsi_boot_create_kobj(struct iscsi_boot_kset *boot_kset,
 	boot_kobj->data = data;
 	boot_kobj->show = show;
 	boot_kobj->is_visible = is_visible;
+	boot_kobj->release = release;
 
 	if (sysfs_create_group(&boot_kobj->kobj, attr_group)) {
 		/*
@@ -331,7 +334,7 @@ iscsi_boot_create_kobj(struct iscsi_boot_kset *boot_kset,
 		 * the boot kobj was not setup and the normal release
 		 * path is not being run.
 		 */
-		boot_kobj->data = NULL;
+		boot_kobj->release = NULL;
 		kobject_put(&boot_kobj->kobj);
 		return NULL;
 	}
@@ -357,6 +360,7 @@ static void iscsi_boot_remove_kobj(struct iscsi_boot_kobj *boot_kobj)
  * @data: driver specific data for target
  * @show: attr show function
  * @is_visible: attr visibility function
+ * @release: release function
  *
  * Note: The boot sysfs lib will free the data passed in for the caller
  * when all refs to the target kobject have been released.
@@ -365,10 +369,12 @@ struct iscsi_boot_kobj *
 iscsi_boot_create_target(struct iscsi_boot_kset *boot_kset, int index,
 			 void *data,
 			 ssize_t (*show) (void *data, int type, char *buf),
-			 mode_t (*is_visible) (void *data, int type))
+			 mode_t (*is_visible) (void *data, int type),
+			 void (*release) (void *data))
 {
 	return iscsi_boot_create_kobj(boot_kset, &iscsi_boot_target_attr_group,
-				      "target%d", index, data, show, is_visible);
+				      "target%d", index, data, show, is_visible,
+				      release);
 }
 EXPORT_SYMBOL_GPL(iscsi_boot_create_target);
 
@@ -379,6 +385,7 @@ EXPORT_SYMBOL_GPL(iscsi_boot_create_target);
  * @data: driver specific data
  * @show: attr show function
  * @is_visible: attr visibility function
+ * @release: release function
  *
  * Note: The boot sysfs lib will free the data passed in for the caller
  * when all refs to the initiator kobject have been released.
@@ -387,12 +394,13 @@ struct iscsi_boot_kobj *
 iscsi_boot_create_initiator(struct iscsi_boot_kset *boot_kset, int index,
 			    void *data,
 			    ssize_t (*show) (void *data, int type, char *buf),
-			    mode_t (*is_visible) (void *data, int type))
+			    mode_t (*is_visible) (void *data, int type),
+			    void (*release) (void *data))
 {
 	return iscsi_boot_create_kobj(boot_kset,
 				      &iscsi_boot_initiator_attr_group,
 				      "initiator", index, data, show,
-				      is_visible);
+				      is_visible, release);
 }
 EXPORT_SYMBOL_GPL(iscsi_boot_create_initiator);
 
@@ -403,6 +411,7 @@ EXPORT_SYMBOL_GPL(iscsi_boot_create_initiator);
  * @data: driver specific data
  * @show: attr show function
  * @is_visible: attr visibility function
+ * @release: release function
  *
  * Note: The boot sysfs lib will free the data passed in for the caller
  * when all refs to the ethernet kobject have been released.
@@ -411,12 +420,13 @@ struct iscsi_boot_kobj *
 iscsi_boot_create_ethernet(struct iscsi_boot_kset *boot_kset, int index,
 			   void *data,
 			   ssize_t (*show) (void *data, int type, char *buf),
-			   mode_t (*is_visible) (void *data, int type))
+			   mode_t (*is_visible) (void *data, int type),
+			   void (*release) (void *data))
 {
 	return iscsi_boot_create_kobj(boot_kset,
 				      &iscsi_boot_ethernet_attr_group,
 				      "ethernet%d", index, data, show,
-				      is_visible);
+				      is_visible, release);
 }
 EXPORT_SYMBOL_GPL(iscsi_boot_create_ethernet);