[PATCH 08/24] n_hdlc: invert conditions in n_hdlc_tty_close and n_hdlc_tty_poll

From: Jiri Slaby
Date: Wed Feb 19 2020 - 03:41:31 EST


This makes the functions return immediatelly on invalid state. And we
can push the indent of the later code one level left.

Pass "-w" to "git show" to see we are changing only the conditions (and
whitespace).

Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/tty/n_hdlc.c | 72 +++++++++++++++++++++++---------------------
1 file changed, 38 insertions(+), 34 deletions(-)

diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index 07ba42badd7a..e40561caa450 100644
--- a/drivers/tty/n_hdlc.c
+++ b/drivers/tty/n_hdlc.c
@@ -258,24 +258,25 @@ static void n_hdlc_tty_close(struct tty_struct *tty)
{
struct n_hdlc *n_hdlc = tty2n_hdlc (tty);

- if (n_hdlc != NULL) {
- if (n_hdlc->magic != HDLC_MAGIC) {
- printk (KERN_WARNING"n_hdlc: trying to close unopened tty!\n");
- return;
- }
+ if (!n_hdlc)
+ return;
+
+ if (n_hdlc->magic != HDLC_MAGIC) {
+ printk(KERN_WARNING "n_hdlc: trying to close unopened tty!\n");
+ return;
+ }
#if defined(TTY_NO_WRITE_SPLIT)
- clear_bit(TTY_NO_WRITE_SPLIT,&tty->flags);
+ clear_bit(TTY_NO_WRITE_SPLIT,&tty->flags);
#endif
- tty->disc_data = NULL;
- if (tty == n_hdlc->backup_tty)
- n_hdlc->backup_tty = NULL;
- if (tty != n_hdlc->tty)
- return;
- if (n_hdlc->backup_tty) {
- n_hdlc->tty = n_hdlc->backup_tty;
- } else {
- n_hdlc_release (n_hdlc);
- }
+ tty->disc_data = NULL;
+ if (tty == n_hdlc->backup_tty)
+ n_hdlc->backup_tty = NULL;
+ if (tty != n_hdlc->tty)
+ return;
+ if (n_hdlc->backup_tty) {
+ n_hdlc->tty = n_hdlc->backup_tty;
+ } else {
+ n_hdlc_release (n_hdlc);
}
} /* end of n_hdlc_tty_close() */

@@ -737,24 +738,27 @@ static __poll_t n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp,
struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
__poll_t mask = 0;

- if (n_hdlc && n_hdlc->magic == HDLC_MAGIC && tty == n_hdlc->tty) {
- /* queue current process into any wait queue that */
- /* may awaken in the future (read and write) */
-
- poll_wait(filp, &tty->read_wait, wait);
- poll_wait(filp, &tty->write_wait, wait);
-
- /* set bits for operations that won't block */
- if (!list_empty(&n_hdlc->rx_buf_list.list))
- mask |= EPOLLIN | EPOLLRDNORM; /* readable */
- if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
- mask |= EPOLLHUP;
- if (tty_hung_up_p(filp))
- mask |= EPOLLHUP;
- if (!tty_is_writelocked(tty) &&
- !list_empty(&n_hdlc->tx_free_buf_list.list))
- mask |= EPOLLOUT | EPOLLWRNORM; /* writable */
- }
+ if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC || tty != n_hdlc->tty)
+ return 0;
+
+ /*
+ * queue the current process into any wait queue that may awaken in the
+ * future (read and write)
+ */
+ poll_wait(filp, &tty->read_wait, wait);
+ poll_wait(filp, &tty->write_wait, wait);
+
+ /* set bits for operations that won't block */
+ if (!list_empty(&n_hdlc->rx_buf_list.list))
+ mask |= EPOLLIN | EPOLLRDNORM; /* readable */
+ if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+ mask |= EPOLLHUP;
+ if (tty_hung_up_p(filp))
+ mask |= EPOLLHUP;
+ if (!tty_is_writelocked(tty) &&
+ !list_empty(&n_hdlc->tx_free_buf_list.list))
+ mask |= EPOLLOUT | EPOLLWRNORM; /* writable */
+
return mask;
} /* end of n_hdlc_tty_poll() */

--
2.25.0