n_tty_read() is a very long function doing too much of different stuff.
Extract the "wait for input" to a separate function:
n_tty_wait_for_input(). It returns an error (< 0), no input (0), or has
potential input (1).
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@xxxxxxxxxx>
---
drivers/tty/n_tty.c | 57 ++++++++++++++++++++++++---------------------
1 file changed, 31 insertions(+), 26 deletions(-)
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 88aa5f9cbe5e..0e3eb18490f0 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -2145,6 +2145,33 @@ static ssize_t n_tty_continue_cookie(struct tty_struct *tty, u8 *kbuf,
return kb - kbuf;
}
+static int n_tty_wait_for_input(struct tty_struct *tty, struct file *file,
+ struct wait_queue_entry *wait, long *timeout)
+{
+ if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+ return -EIO;
+ if (tty_hung_up_p(file))
+ return 0;
+ /*
+ * Abort readers for ttys which never actually get hung up.
+ * See __tty_hangup().
+ */
+ if (test_bit(TTY_HUPPING, &tty->flags))
+ return 0;
+ if (!*timeout)
+ return 0;
+ if (tty_io_nonblock(tty, file))
+ return -EAGAIN;
+ if (signal_pending(current))
+ return -ERESTARTSYS;
+
+ up_read(&tty->termios_rwsem);
+ *timeout = wait_woken(wait, TASK_INTERRUPTIBLE, *timeout);
+ down_read(&tty->termios_rwsem);
+
+ return 1;
+}
+
/**
* n_tty_read - read function for tty
* @tty: tty device
@@ -2234,34 +2261,12 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, u8 *kbuf,
tty_buffer_flush_work(tty->port);
down_read(&tty->termios_rwsem);
if (!input_available_p(tty, 0)) {
- if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
- retval = -EIO;
+ int ret = n_tty_wait_for_input(tty, file, &wait,
+ &timeout);
+ if (ret <= 0) {
+ retval = ret;
break;
}
- if (tty_hung_up_p(file))
- break;
- /*
- * Abort readers for ttys which never actually
- * get hung up. See __tty_hangup().
- */
- if (test_bit(TTY_HUPPING, &tty->flags))
- break;
- if (!timeout)
- break;
- if (tty_io_nonblock(tty, file)) {
- retval = -EAGAIN;
- break;
- }
- if (signal_pending(current)) {
- retval = -ERESTARTSYS;
- break;
- }
- up_read(&tty->termios_rwsem);
-
- timeout = wait_woken(&wait, TASK_INTERRUPTIBLE,
- timeout);
-
- down_read(&tty->termios_rwsem);
continue;
}
}
--
2.48.1
