1 files changed, 57 insertions, 36 deletions

diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index ea09aaa3cab..0cea9782d7d 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>
@@ -238,7 +239,6 @@
 #include <linux/string.h>
 #include <linux/suspend.h>
 #include <linux/utsname.h>
-#include <linux/wait.h>
 
 #include <linux/usb_ch9.h>
 #include <linux/usb_gadget.h>
@@ -250,7 +250,7 @@
 
 #define DRIVER_DESC		"File-backed Storage Gadget"
 #define DRIVER_NAME		"g_file_storage"
-#define DRIVER_VERSION		"20 October 2004"
+#define DRIVER_VERSION		"28 November 2005"
 
 static const char longname[] = DRIVER_DESC;
 static const char shortname[] = DRIVER_NAME;
@@ -335,8 +335,8 @@ MODULE_LICENSE("Dual BSD/GPL");
 #define MAX_LUNS	8
 
 	/* Arggh!  There should be a module_param_array_named macro! */
-static char		*file[MAX_LUNS] = {NULL, };
-static int		ro[MAX_LUNS] = {0, };
+static char		*file[MAX_LUNS];
+static int		ro[MAX_LUNS];
 
 static struct {
 	int		num_filenames;
@@ -587,7 +587,7 @@ enum fsg_buffer_state {
 struct fsg_buffhd {
 	void				*buf;
 	dma_addr_t			dma;
-	volatile enum fsg_buffer_state	state;
+	enum fsg_buffer_state		state;
 	struct fsg_buffhd		*next;
 
 	/* The NetChip 2280 is faster, and handles some protocol faults
@@ -596,9 +596,9 @@ struct fsg_buffhd {
 	unsigned int			bulk_out_intended_length;
 
 	struct usb_request		*inreq;
-	volatile int			inreq_busy;
+	int				inreq_busy;
 	struct usb_request		*outreq;
-	volatile int			outreq_busy;
+	int				outreq_busy;
 };
 
 enum fsg_state {
@@ -631,13 +631,16 @@ 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;
+	unsigned int		ep0_req_tag;
 	const char		*ep0req_name;
 
 	struct usb_request	*intreq;	// For interrupt responses
-	volatile int		intreq_busy;
+	int			intreq_busy;
 	struct fsg_buffhd	*intr_buffhd;
 
  	unsigned int		bulk_out_maxpacket;
@@ -667,7 +670,6 @@ struct fsg_dev {
 	struct fsg_buffhd	*next_buffhd_to_drain;
 	struct fsg_buffhd	buffhds[NUM_BUFFERS];
 
-	wait_queue_head_t	thread_wqh;
 	int			thread_wakeup_needed;
 	struct completion	thread_notifier;
 	struct task_struct	*thread_task;
@@ -694,7 +696,6 @@ struct fsg_dev {
 	unsigned int		nluns;
 	struct lun		*luns;
 	struct lun		*curlun;
-	struct completion	lun_released;
 };
 
 typedef void (*fsg_routine_t)(struct fsg_dev *);
@@ -1073,11 +1074,13 @@ static int populate_config_buf(struct usb_gadget *gadget,
 
 /* These routines may be called in process context or in_irq */
 
+/* Caller must hold fsg->lock */
 static void wakeup_thread(struct fsg_dev *fsg)
 {
 	/* Tell the main thread that something has happened */
 	fsg->thread_wakeup_needed = 1;
-	wake_up_all(&fsg->thread_wqh);
+	if (fsg->thread_task)
+		wake_up_process(fsg->thread_task);
 }
 
 
@@ -1164,11 +1167,12 @@ static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
 		usb_ep_fifo_flush(ep);
 
 	/* Hold the lock while we update the request and buffer states */
+	smp_wmb();
 	spin_lock(&fsg->lock);
 	bh->inreq_busy = 0;
 	bh->state = BUF_STATE_EMPTY;
-	spin_unlock(&fsg->lock);
 	wakeup_thread(fsg);
+	spin_unlock(&fsg->lock);
 }
 
 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
@@ -1185,11 +1189,12 @@ static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
 		usb_ep_fifo_flush(ep);
 
 	/* Hold the lock while we update the request and buffer states */
+	smp_wmb();
 	spin_lock(&fsg->lock);
 	bh->outreq_busy = 0;
 	bh->state = BUF_STATE_FULL;
-	spin_unlock(&fsg->lock);
 	wakeup_thread(fsg);
+	spin_unlock(&fsg->lock);
 }
 
 
@@ -1206,11 +1211,12 @@ static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
 		usb_ep_fifo_flush(ep);
 
 	/* Hold the lock while we update the request and buffer states */
+	smp_wmb();
 	spin_lock(&fsg->lock);
 	fsg->intreq_busy = 0;
 	bh->state = BUF_STATE_EMPTY;
-	spin_unlock(&fsg->lock);
 	wakeup_thread(fsg);
+	spin_unlock(&fsg->lock);
 }
 
 #else
@@ -1261,8 +1267,8 @@ static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
 	fsg->cbbuf_cmnd_size = req->actual;
 	memcpy(fsg->cbbuf_cmnd, req->buf, fsg->cbbuf_cmnd_size);
 
-	spin_unlock(&fsg->lock);
 	wakeup_thread(fsg);
+	spin_unlock(&fsg->lock);
 }
 
 #else
@@ -1514,8 +1520,8 @@ static int fsg_setup(struct usb_gadget *gadget,
 
 /* Use this for bulk or interrupt transfers, not ep0 */
 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
-		struct usb_request *req, volatile int *pbusy,
-		volatile enum fsg_buffer_state *state)
+		struct usb_request *req, int *pbusy,
+		enum fsg_buffer_state *state)
 {
 	int	rc;
 
@@ -1523,8 +1529,11 @@ static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
 		dump_msg(fsg, "bulk-in", req->buf, req->length);
 	else if (ep == fsg->intr_in)
 		dump_msg(fsg, "intr-in", req->buf, req->length);
+
+	spin_lock_irq(&fsg->lock);
 	*pbusy = 1;
 	*state = BUF_STATE_BUSY;
+	spin_unlock_irq(&fsg->lock);
 	rc = usb_ep_queue(ep, req, GFP_KERNEL);
 	if (rc != 0) {
 		*pbusy = 0;
@@ -1544,14 +1553,23 @@ static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
 
 static int sleep_thread(struct fsg_dev *fsg)
 {
-	int	rc;
+	int	rc = 0;
 
 	/* Wait until a signal arrives or we are woken up */
-	rc = wait_event_interruptible(fsg->thread_wqh,
-			fsg->thread_wakeup_needed);
+	for (;;) {
+		try_to_freeze();
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (signal_pending(current)) {
+			rc = -EINTR;
+			break;
+		}
+		if (fsg->thread_wakeup_needed)
+			break;
+		schedule();
+	}
+	__set_current_state(TASK_RUNNING);
 	fsg->thread_wakeup_needed = 0;
-	try_to_freeze();
-	return (rc ? -EINTR : 0);
+	return rc;
 }
 
 
@@ -1788,6 +1806,7 @@ static int do_write(struct fsg_dev *fsg)
 		if (bh->state == BUF_STATE_EMPTY && !get_some_more)
 			break;			// We stopped early
 		if (bh->state == BUF_STATE_FULL) {
+			smp_rmb();
 			fsg->next_buffhd_to_drain = bh->next;
 			bh->state = BUF_STATE_EMPTY;
 
@@ -2356,6 +2375,7 @@ static int throw_away_data(struct fsg_dev *fsg)
 
 		/* Throw away the data in a filled buffer */
 		if (bh->state == BUF_STATE_FULL) {
+			smp_rmb();
 			bh->state = BUF_STATE_EMPTY;
 			fsg->next_buffhd_to_drain = bh->next;
 
@@ -3021,6 +3041,7 @@ static int get_next_command(struct fsg_dev *fsg)
 			if ((rc = sleep_thread(fsg)) != 0)
 				return rc;
 			}
+		smp_rmb();
 		rc = received_cbw(fsg, bh);
 		bh->state = BUF_STATE_EMPTY;
 
@@ -3642,11 +3663,19 @@ 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 +3689,12 @@ 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 +3873,7 @@ 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]) {
@@ -4061,7 +4089,7 @@ static int __init fsg_alloc(void)
 		return -ENOMEM;
 	spin_lock_init(&fsg->lock);
 	init_rwsem(&fsg->filesem);
-	init_waitqueue_head(&fsg->thread_wqh);
+	kref_init(&fsg->ref);
 	init_completion(&fsg->thread_notifier);
 
 	the_fsg = fsg;
@@ -4069,13 +4097,6 @@ 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 +4106,7 @@ 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 +4124,6 @@ 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);