n_tty_read() is a very long function doing too much of different stuff.
Extract the "cookie" (continuation read) handling to a separate
function: n_tty_continue_cookie().
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@xxxxxxxxxx>
---
drivers/tty/n_tty.c | 66 ++++++++++++++++++++++++---------------------
1 file changed, 36 insertions(+), 30 deletions(-)
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 43ba740792d9..88aa5f9cbe5e 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -2111,6 +2111,39 @@ static int job_control(struct tty_struct *tty, struct file *file)
return __tty_check_change(tty, SIGTTIN);
}
+/*
+ * We still hold the atomic_read_lock and the termios_rwsem, and can just
+ * continue to copy data.
+ */
+static ssize_t n_tty_continue_cookie(struct tty_struct *tty, u8 *kbuf,
+ size_t nr, void **cookie)
+{
+ struct n_tty_data *ldata = tty->disc_data;
+ u8 *kb = kbuf;
+
+ if (ldata->icanon && !L_EXTPROC(tty)) {
+ /*
+ * If we have filled the user buffer, see if we should skip an
+ * EOF character before releasing the lock and returning done.
+ */
+ if (!nr)
+ canon_skip_eof(ldata);
+ else if (canon_copy_from_read_buf(tty, &kb, &nr))
+ return kb - kbuf;
+ } else {
+ if (copy_from_read_buf(tty, &kb, &nr))
+ return kb - kbuf;
+ }
+
+ /* No more data - release locks and stop retries */
+ n_tty_kick_worker(tty);
+ n_tty_check_unthrottle(tty);
+ up_read(&tty->termios_rwsem);
+ mutex_unlock(&ldata->atomic_read_lock);
+ *cookie = NULL;
+
+ return kb - kbuf;
+}
/**
* n_tty_read - read function for tty
@@ -2144,36 +2177,9 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, u8 *kbuf,
bool packet;
size_t old_tail;
- /*
- * Is this a continuation of a read started earler?
- *
- * If so, we still hold the atomic_read_lock and the
- * termios_rwsem, and can just continue to copy data.
- */
- if (*cookie) {
- if (ldata->icanon && !L_EXTPROC(tty)) {
- /*
- * If we have filled the user buffer, see
- * if we should skip an EOF character before
- * releasing the lock and returning done.
- */
- if (!nr)
- canon_skip_eof(ldata);
- else if (canon_copy_from_read_buf(tty, &kb, &nr))
- return kb - kbuf;
- } else {
- if (copy_from_read_buf(tty, &kb, &nr))
- return kb - kbuf;
- }
-
- /* No more data - release locks and stop retries */
- n_tty_kick_worker(tty);
- n_tty_check_unthrottle(tty);
- up_read(&tty->termios_rwsem);
- mutex_unlock(&ldata->atomic_read_lock);
- *cookie = NULL;
- return kb - kbuf;
- }
+ /* Is this a continuation of a read started earlier? */
+ if (*cookie)
+ return n_tty_continue_cookie(tty, kbuf, nr, cookie);
retval = job_control(tty, file);
if (retval < 0)
--
2.48.1
