USB: mark "reject" field of struct urb as atomic_t

It is enough to protect accesses to reject field of urb
by marking it as atomic_t,also it is the only reason of
existence of usb_reject_lock,so remove the lock to make
code more clean.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index a007987..3c711db 100644 (file)
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1010,7 +1010,7 @@ int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
        spin_lock(&hcd_urb_list_lock);
 
        /* Check that the URB isn't being killed */
-       if (unlikely(urb->reject)) {
+       if (unlikely(atomic_read(&urb->reject))) {
                rc = -EPERM;
                goto done;
        }
@@ -1340,7 +1340,7 @@ int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
                INIT_LIST_HEAD(&urb->urb_list);
                atomic_dec(&urb->use_count);
                atomic_dec(&urb->dev->urbnum);
-               if (urb->reject)
+               if (atomic_read(&urb->reject))
                        wake_up(&usb_kill_urb_queue);
                usb_put_urb(urb);
        }
@@ -1444,7 +1444,7 @@ void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
        urb->status = status;
        urb->complete (urb);
        atomic_dec (&urb->use_count);
-       if (unlikely (urb->reject))
+       if (unlikely(atomic_read(&urb->reject)))
                wake_up (&usb_kill_urb_queue);
        usb_put_urb (urb);
 }

diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c
index 1f68af9..b5e9948 100644 (file)
--- a/drivers/usb/core/urb.c
+++ b/drivers/usb/core/urb.c
@@ -10,7 +10,6 @@
 
 #define to_urb(d) container_of(d, struct urb, kref)
 
-static DEFINE_SPINLOCK(usb_reject_lock);
 
 static void urb_destroy(struct kref *kref)
 {
@@ -131,9 +130,7 @@ void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor)
        urb->anchor = anchor;
 
        if (unlikely(anchor->poisoned)) {
-               spin_lock(&usb_reject_lock);
-               urb->reject++;
-               spin_unlock(&usb_reject_lock);
+               atomic_inc(&urb->reject);
        }
 
        spin_unlock_irqrestore(&anchor->lock, flags);
@@ -565,16 +562,12 @@ void usb_kill_urb(struct urb *urb)
        might_sleep();
        if (!(urb && urb->dev && urb->ep))
                return;
-       spin_lock_irq(&usb_reject_lock);
-       ++urb->reject;
-       spin_unlock_irq(&usb_reject_lock);
+       atomic_inc(&urb->reject);
 
        usb_hcd_unlink_urb(urb, -ENOENT);
        wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0);
 
-       spin_lock_irq(&usb_reject_lock);
-       --urb->reject;
-       spin_unlock_irq(&usb_reject_lock);
+       atomic_dec(&urb->reject);
 }
 EXPORT_SYMBOL_GPL(usb_kill_urb);
 
@@ -606,9 +599,7 @@ void usb_poison_urb(struct urb *urb)
        might_sleep();
        if (!(urb && urb->dev && urb->ep))
                return;
-       spin_lock_irq(&usb_reject_lock);
-       ++urb->reject;
-       spin_unlock_irq(&usb_reject_lock);
+       atomic_inc(&urb->reject);
 
        usb_hcd_unlink_urb(urb, -ENOENT);
        wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0);
@@ -617,14 +608,10 @@ EXPORT_SYMBOL_GPL(usb_poison_urb);
 
 void usb_unpoison_urb(struct urb *urb)
 {
-       unsigned long flags;
-
        if (!urb)
                return;
 
-       spin_lock_irqsave(&usb_reject_lock, flags);
-       --urb->reject;
-       spin_unlock_irqrestore(&usb_reject_lock, flags);
+       atomic_dec(&urb->reject);
 }
 EXPORT_SYMBOL_GPL(usb_unpoison_urb);
 

diff --git a/include/linux/usb.h b/include/linux/usb.h
index e9d6356..4e8654a 100644 (file)
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -1340,7 +1340,7 @@ struct urb {
        struct kref kref;               /* reference count of the URB */
        void *hcpriv;                   /* private data for host controller */
        atomic_t use_count;             /* concurrent submissions counter */
-       u8 reject;                      /* submissions will fail */
+       atomic_t reject;                /* submissions will fail */
        int unlinked;                   /* unlink error code */
 
        /* public: documented fields in the urb that can be used by drivers */