[PATCH -next v2 15/26] tty: Simplify tty_ldisc_release() interface

Peter Hurley
2014-11-05T17:49:57Z

Passing the 'other' tty to tty_ldisc_release() only makes sense
for a pty pair; make o_tty function local instead.

Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
---
drivers/tty/tty_io.c | 2 +-
drivers/tty/tty_ldisc.c | 15 +++++++--------
include/linux/tty.h | 2 +-
3 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 563ab37..4034e5e 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1901,7 +1901,7 @@ int tty_release(struct inode *inode, struct file *filp)
/*
* Ask the line discipline code to release its structures
*/
- tty_ldisc_release(tty, o_tty);
+ tty_ldisc_release(tty);

/* Wait for pending work before tty destruction commmences */
tty_flush_works(tty);
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 49001fa..1c4d7b6 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -756,18 +756,17 @@ static void tty_ldisc_kill(struct tty_struct *tty)

/**
* tty_ldisc_release - release line discipline
- * @tty: tty being shut down
- * @o_tty: pair tty for pty/tty pairs
- *
- * Called during the final close of a tty/pty pair in order to shut down
- * the line discpline layer. On exit the ldisc assigned is N_TTY and the
- * ldisc has not been opened.
+ * @tty: tty being shut down (or one end of pty pair)
*
- * Holding ldisc_sem write lock serializes tty->ldisc changes.
+ * Called during the final close of a tty or a pty pair in order to shut
+ * down the line discpline layer. On exit, each ldisc assigned is N_TTY and
+ * each ldisc has not been opened.
*/

-void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty)
+void tty_ldisc_release(struct tty_struct *tty)
{
+ struct tty_struct *o_tty = tty->link;
+
/*
* Shutdown this line discipline. As this is the final close,
* it does not race with the set_ldisc code path.
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 35b29f0..af1a7f3 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -557,7 +557,7 @@ extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
extern int tty_unregister_ldisc(int disc);
extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
-extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
+extern void tty_ldisc_release(struct tty_struct *tty);
extern void tty_ldisc_init(struct tty_struct *tty);
extern void tty_ldisc_deinit(struct tty_struct *tty);
extern void tty_ldisc_begin(void);
--
2.1.3