n_hdlc: invert conditions in n_hdlc_tty_close and n_hdlc_tty_poll

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@suse.cz>
Link: https://lore.kernel.org/r/20200219084118.26491-8-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index 07ba42badd7a21ecb3cf9394d0e8409a0507ed9b..e40561caa45034bfbc9987459ca6932a143baaaf 100644 (file)
--- 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() */