[04/15] timers: Get rid of del_singleshot_timer_sync()

Commit Message

Thomas Gleixner Nov. 15, 2022, 8:28 p.m. UTC

del_singleshot_timer_sync() used to be an optimization for deleting timers
which are not rearmed from the timer callback function.

This optimization turned out to be broken and got mapped to
del_timer_sync() about 17 years ago.

Get rid of the undocumented indirection and use del_timer_sync() directly.

No functional change.

Signed-off-by: Thomas Gleixner <[e-mail]>
---
 drivers/char/tpm/tpm-dev-common.c     |    4 ++--
 drivers/staging/wlan-ng/hfa384x_usb.c |    4 ++--
 drivers/staging/wlan-ng/prism2usb.c   |    6 +++---
 include/linux/timer.h                 |    2 --
 kernel/time/timer.c                   |    2 +-
 net/sunrpc/xprt.c                     |    2 +-
 6 files changed, 9 insertions(+), 11 deletions(-)

Comments

Steven Rostedt Nov. 21, 2022, 8:08 p.m. UTC | #1

On Tue, 15 Nov 2022 21:28:39 +0100 (CET)
Thomas Gleixner <[e-mail]> wrote:

> del_singleshot_timer_sync() used to be an optimization for deleting timers
> which are not rearmed from the timer callback function.
> 
> This optimization turned out to be broken and got mapped to
> del_timer_sync() about 17 years ago.
> 
> Get rid of the undocumented indirection and use del_timer_sync() directly.
> 
> No functional change.
> 
> Signed-off-by: Thomas Gleixner <[e-mail]>
>


> --- a/net/sunrpc/xprt.c
> +++ b/net/sunrpc/xprt.c
> @@ -1164,7 +1164,7 @@ xprt_request_enqueue_receive(struct rpc_
>  	spin_unlock(&xprt->queue_lock);
>  
>  	/* Turn off autodisconnect */
> -	del_singleshot_timer_sync(&xprt->timer);
> +	del_timer_sync(&xprt->timer);

And this was not even a single shot timer. It used the
del_singleshot_timer_sync() function because of incorrect assumptions.

Link: https://lore.kernel.org/all/[e-mail]/

  0f9dc2b16884b ("RPC: Clean up socket autodisconnect")
  55c888d6d09a0 ("timers fixes/improvements")

Reviewed-by: Steven Rostedt (Google) <[e-mail]>

-- Steve


>  	return 0;
>  }
>

Patch

--- a/drivers/char/tpm/tpm-dev-common.c
+++ b/drivers/char/tpm/tpm-dev-common.c
@@ -155,7 +155,7 @@  ssize_t tpm_common_read(struct file *fil
 out:
 	if (!priv->response_length) {
 		*off = 0;
-		del_singleshot_timer_sync(&priv->user_read_timer);
+		del_timer_sync(&priv->user_read_timer);
 		flush_work(&priv->timeout_work);
 	}
 	mutex_unlock(&priv->buffer_mutex);
@@ -262,7 +262,7 @@  ssize_t tpm_common_write(struct file *fi
 void tpm_common_release(struct file *file, struct file_priv *priv)
 {
 	flush_work(&priv->async_work);
-	del_singleshot_timer_sync(&priv->user_read_timer);
+	del_timer_sync(&priv->user_read_timer);
 	flush_work(&priv->timeout_work);
 	file->private_data = NULL;
 	priv->response_length = 0;
--- a/drivers/staging/wlan-ng/hfa384x_usb.c
+++ b/drivers/staging/wlan-ng/hfa384x_usb.c
@@ -1116,8 +1116,8 @@  static int hfa384x_usbctlx_complete_sync
 		if (ctlx == get_active_ctlx(hw)) {
 			spin_unlock_irqrestore(&hw->ctlxq.lock, flags);
 
-			del_singleshot_timer_sync(&hw->reqtimer);
-			del_singleshot_timer_sync(&hw->resptimer);
+			del_timer_sync(&hw->reqtimer);
+			del_timer_sync(&hw->resptimer);
 			hw->req_timer_done = 1;
 			hw->resp_timer_done = 1;
 			usb_kill_urb(&hw->ctlx_urb);
--- a/drivers/staging/wlan-ng/prism2usb.c
+++ b/drivers/staging/wlan-ng/prism2usb.c
@@ -170,9 +170,9 @@  static void prism2sta_disconnect_usb(str
 		 */
 		prism2sta_ifstate(wlandev, P80211ENUM_ifstate_disable);
 
-		del_singleshot_timer_sync(&hw->throttle);
-		del_singleshot_timer_sync(&hw->reqtimer);
-		del_singleshot_timer_sync(&hw->resptimer);
+		del_timer_sync(&hw->throttle);
+		del_timer_sync(&hw->reqtimer);
+		del_timer_sync(&hw->resptimer);
 
 		/* Unlink all the URBs. This "removes the wheels"
 		 * from the entire CTLX handling mechanism.
--- a/include/linux/timer.h
+++ b/include/linux/timer.h
@@ -190,8 +190,6 @@  extern int try_to_del_timer_sync(struct
 # define del_timer_sync(t)		del_timer(t)
 #endif
 
-#define del_singleshot_timer_sync(t) del_timer_sync(t)
-
 extern void init_timers(void);
 struct hrtimer;
 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -1933,7 +1933,7 @@  signed long __sched schedule_timeout(sig
 	timer_setup_on_stack(&timer.timer, process_timeout, 0);
 	__mod_timer(&timer.timer, expire, MOD_TIMER_NOTPENDING);
 	schedule();
-	del_singleshot_timer_sync(&timer.timer);
+	del_timer_sync(&timer.timer);
 
 	/* Remove the timer from the object tracker */
 	destroy_timer_on_stack(&timer.timer);
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -1164,7 +1164,7 @@  xprt_request_enqueue_receive(struct rpc_
 	spin_unlock(&xprt->queue_lock);
 
 	/* Turn off autodisconnect */
-	del_singleshot_timer_sync(&xprt->timer);
+	del_timer_sync(&xprt->timer);
 	return 0;
 }