tty: invert return values of tty_{,un}throttle_safe()

If tty_{,un}throttle_safe() returned true on success (similar to
*_trylock()), it would make the conditions in callers more obvious. So
perform the switch to these inverted values (and fix the callers).

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230919085156.1578-8-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index b34e661..f252d0b 100644 (file)
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -253,7 +253,7 @@ static void n_tty_check_throttle(struct tty_struct *tty)
                tty_set_flow_change(tty, TTY_THROTTLE_SAFE);
                if (N_TTY_BUF_SIZE - read_cnt(ldata) >= TTY_THRESHOLD_THROTTLE)
                        break;
-       } while (tty_throttle_safe(tty));
+       } while (!tty_throttle_safe(tty));
 
        __tty_set_flow_change(tty, 0);
 }
@@ -282,7 +282,7 @@ static void n_tty_check_unthrottle(struct tty_struct *tty)
                        break;
 
                n_tty_kick_worker(tty);
-       } while (tty_unthrottle_safe(tty));
+       } while (!tty_unthrottle_safe(tty));
 
        __tty_set_flow_change(tty, 0);
 }

diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
index ba60fcf..fb2f1ac 100644 (file)
--- a/drivers/tty/tty_ioctl.c
+++ b/drivers/tty/tty_ioctl.c
@@ -124,16 +124,16 @@ EXPORT_SYMBOL(tty_unthrottle);
  *     conditions when throttling is conditional on factors evaluated prior to
  *     throttling.
  *
- *     Returns false if tty is throttled (or was already throttled)
+ *     Returns true if tty is throttled (or was already throttled)
  */
 bool tty_throttle_safe(struct tty_struct *tty)
 {
-       bool ret = false;
+       bool ret = true;
 
        mutex_lock(&tty->throttle_mutex);
        if (!tty_throttled(tty)) {
                if (tty->flow_change != TTY_THROTTLE_SAFE)
-                       ret = true;
+                       ret = false;
                else {
                        set_bit(TTY_THROTTLED, &tty->flags);
                        if (tty->ops->throttle)
@@ -154,16 +154,16 @@ bool tty_throttle_safe(struct tty_struct *tty)
  *     unthrottle due to race conditions when unthrottling is conditional
  *     on factors evaluated prior to unthrottling.
  *
- *     Returns false if tty is unthrottled (or was already unthrottled)
+ *     Returns true if tty is unthrottled (or was already unthrottled)
  */
 bool tty_unthrottle_safe(struct tty_struct *tty)
 {
-       bool ret = false;
+       bool ret = true;
 
        mutex_lock(&tty->throttle_mutex);
        if (tty_throttled(tty)) {
                if (tty->flow_change != TTY_UNTHROTTLE_SAFE)
-                       ret = true;
+                       ret = false;
                else {
                        clear_bit(TTY_THROTTLED, &tty->flags);
                        if (tty->ops->unthrottle)