1 files changed, 17 insertions, 13 deletions

diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index ea09aaa3cab6..f6f0b2aa1145 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -224,6 +224,7 @@
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/kref.h>
 #include <linux/kthread.h>
 #include <linux/limits.h>
 #include <linux/list.h>
@@ -631,6 +632,9 @@ struct fsg_dev {
         /* filesem protects: backing files in use */
         struct rw_semaphore     filesem;
 
+        /* reference counting: wait until all LUNs are released */
+        struct kref             ref;
+
         struct usb_ep           *ep0;           // Handy copy of gadget->ep0
         struct usb_request      *ep0req;        // For control responses
         volatile unsigned int   ep0_req_tag;
@@ -694,7 +698,6 @@ struct fsg_dev {
         unsigned int            nluns;
         struct lun              *luns;
         struct lun              *curlun;
-        struct completion       lun_released;
 };
 
 typedef void (*fsg_routine_t)(struct fsg_dev *);
@@ -3642,11 +3645,19 @@ static DEVICE_ATTR(file, 0444, show_file, NULL);
 
 /*-------------------------------------------------------------------------*/
 
+static void fsg_release(struct kref *ref)
+{
+        struct fsg_dev  *fsg = container_of(ref, struct fsg_dev, ref);
+
+        kfree(fsg->luns);
+        kfree(fsg);
+}
+
 static void lun_release(struct device *dev)
 {
         struct fsg_dev  *fsg = (struct fsg_dev *) dev_get_drvdata(dev);
 
-        complete(&fsg->lun_released);
+        kref_put(&fsg->ref, fsg_release);
 }
 
 static void fsg_unbind(struct usb_gadget *gadget)
@@ -3660,14 +3671,12 @@ static void fsg_unbind(struct usb_gadget *gadget)
         clear_bit(REGISTERED, &fsg->atomic_bitflags);
 
         /* Unregister the sysfs attribute files and the LUNs */
-        init_completion(&fsg->lun_released);
         for (i = 0; i < fsg->nluns; ++i) {
                 curlun = &fsg->luns[i];
                 if (curlun->registered) {
                         device_remove_file(&curlun->dev, &dev_attr_ro);
                         device_remove_file(&curlun->dev, &dev_attr_file);
                         device_unregister(&curlun->dev);
-                        wait_for_completion(&fsg->lun_released);
                         curlun->registered = 0;
                 }
         }
@@ -3846,6 +3855,7 @@ static int __init fsg_bind(struct usb_gadget *gadget)
                         curlun->dev.release = lun_release;
                         device_create_file(&curlun->dev, &dev_attr_ro);
                         device_create_file(&curlun->dev, &dev_attr_file);
+                        kref_get(&fsg->ref);
                 }
 
                 if (file[i] && *file[i]) {
@@ -4061,6 +4071,7 @@ static int __init fsg_alloc(void)
                 return -ENOMEM;
         spin_lock_init(&fsg->lock);
         init_rwsem(&fsg->filesem);
+        kref_init(&fsg->ref);
         init_waitqueue_head(&fsg->thread_wqh);
         init_completion(&fsg->thread_notifier);
 
@@ -4069,13 +4080,6 @@ static int __init fsg_alloc(void)
 }
 
 
-static void fsg_free(struct fsg_dev *fsg)
-{
-        kfree(fsg->luns);
-        kfree(fsg);
-}
-
-
 static int __init fsg_init(void)
 {
         int             rc;
@@ -4085,7 +4089,7 @@ static int __init fsg_init(void)
                 return rc;
         fsg = the_fsg;
         if ((rc = usb_gadget_register_driver(&fsg_driver)) != 0)
-                fsg_free(fsg);
+                kref_put(&fsg->ref, fsg_release);
         return rc;
 }
 module_init(fsg_init);
@@ -4103,6 +4107,6 @@ static void __exit fsg_cleanup(void)
         wait_for_completion(&fsg->thread_notifier);
 
         close_all_backing_files(fsg);
-        fsg_free(fsg);
+        kref_put(&fsg->ref, fsg_release);
 }
 module_exit(fsg_cleanup);