Merge "USB: f_fs: Move ep completion out of stack"

drivers/usb/gadget/f_fs.c

@@ -141,6 +141,8 @@ struct ffs_data {
 	struct usb_request		*ep0req;		/* P: mutex */
 	struct completion		ep0req_completion;	/* P: mutex */
 	int				ep0req_status;		/* P: mutex */
+	struct completion		epin_completion;
+	struct completion		epout_completion;
 
 	/* reference counter */
 	atomic_t			ref;
@@ -749,8 +751,11 @@ static const struct file_operations ffs_ep0_operations = {
 
 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
 {
+	struct ffs_ep *ep = _ep->driver_data;
 	ENTER();
-	if (likely(req->context)) {
+
+	/* req may be freed during unbind */
+	if (ep && ep->req && likely(req->context)) {
 		struct ffs_ep *ep = _ep->driver_data;
 		ep->status = req->status ? req->status : req->actual;
 		complete(req->context);
@@ -762,6 +767,7 @@ static ssize_t ffs_epfile_io(struct file *file,
 {
 	struct ffs_epfile *epfile = file->private_data;
 	struct ffs_ep *ep;
+	struct ffs_data *ffs = epfile->ffs;
 	char *data = NULL;
 	ssize_t ret;
 	int halt;
@@ -860,21 +866,27 @@ static ssize_t ffs_epfile_io(struct file *file,
 		ret = -EBADMSG;
 	} else {
 		/* Fire the request */
-		DECLARE_COMPLETION_ONSTACK(done);
+		struct completion *done;
 
 		struct usb_request *req = ep->req;
-		req->context  = &done;
 		req->complete = ffs_epfile_io_complete;
 		req->buf      = data;
 		req->length   = buffer_len;
 
+		if (read) {
+			INIT_COMPLETION(ffs->epout_completion);
+			req->context  = done = &ffs->epout_completion;
+		} else {
+			INIT_COMPLETION(ffs->epin_completion);
+			req->context  = done = &ffs->epin_completion;
+		}
 		ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
 
 		spin_unlock_irq(&epfile->ffs->eps_lock);
 
 		if (unlikely(ret < 0)) {
 			ret = -EIO;
-		} else if (unlikely(wait_for_completion_interruptible(&done))) {
+		} else if (unlikely(wait_for_completion_interruptible(done))) {
 			spin_lock_irq(&epfile->ffs->eps_lock);
 			/*
 			 * While we were acquiring lock endpoint got disabled
@@ -1365,6 +1377,8 @@ static struct ffs_data *ffs_data_new(void)
 	spin_lock_init(&ffs->eps_lock);
 	init_waitqueue_head(&ffs->ev.waitq);
 	init_completion(&ffs->ep0req_completion);
+	init_completion(&ffs->epout_completion);
+	init_completion(&ffs->epin_completion);
 
 	/* XXX REVISIT need to update it in some places, or do we? */
 	ffs->ev.can_stall = 1;