[PATCH 07/15] tty: invert return values of tty_{,un}throttle_safe()

From: Jiri Slaby (SUSE)
Date: Tue Sep 19 2023 - 04:52:33 EST


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@xxxxxxxxxx>
---
drivers/tty/n_tty.c | 4 ++--
drivers/tty/tty_ioctl.c | 12 ++++++------
2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index b34e6612aef6..f252d0b5a434 100644
--- 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 ba60fcf518e0..fb2f1ac5172f 100644
--- 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)
--
2.42.0