1 files changed, 65 insertions, 58 deletions

diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 4d5e84097..51e0d3288 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -7,7 +7,6 @@
  */
 
 #include <linux/module.h>
-
 #include <linux/errno.h>
 #include <linux/interrupt.h>
 #include <linux/tty.h>
@@ -26,6 +25,12 @@
 #include <linux/mutex.h>
 #include <linux/poll.h>
 
+#undef TTY_DEBUG_HANGUP
+#ifdef TTY_DEBUG_HANGUP
+# define tty_debug_hangup(tty, f, args...)	tty_debug(tty, f, ##args)
+#else
+# define tty_debug_hangup(tty, f, args...)	do {} while (0)
+#endif
 
 #ifdef CONFIG_UNIX98_PTYS
 static struct tty_driver *ptm_driver;
@@ -39,7 +44,7 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
 	if (tty->driver->subtype == PTY_TYPE_MASTER)
 		WARN_ON(tty->count > 1);
 	else {
-		if (test_bit(TTY_IO_ERROR, &tty->flags))
+		if (tty_io_error(tty))
 			return;
 		if (tty->count > 2)
 			return;
@@ -54,7 +59,7 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
 	if (!tty->link)
 		return;
 	set_bit(TTY_OTHER_CLOSED, &tty->link->flags);
-	tty_flip_buffer_push(tty->link->port);
+	wake_up_interruptible(&tty->link->read_wait);
 	wake_up_interruptible(&tty->link->write_wait);
 	if (tty->driver->subtype == PTY_TYPE_MASTER) {
 		set_bit(TTY_OTHER_CLOSED, &tty->flags);
@@ -242,9 +247,7 @@ static int pty_open(struct tty_struct *tty, struct file *filp)
 		goto out;
 
 	clear_bit(TTY_IO_ERROR, &tty->flags);
-	/* TTY_OTHER_CLOSED must be cleared before TTY_OTHER_DONE */
 	clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
-	clear_bit(TTY_OTHER_DONE, &tty->link->flags);
 	set_bit(TTY_THROTTLED, &tty->flags);
 	return 0;
 
@@ -258,8 +261,7 @@ static void pty_set_termios(struct tty_struct *tty,
 {
 	/* See if packet mode change of state. */
 	if (tty->link && tty->link->packet) {
-		int extproc = (old_termios->c_lflag & EXTPROC) |
-				(tty->termios.c_lflag & EXTPROC);
+		int extproc = (old_termios->c_lflag & EXTPROC) | L_EXTPROC(tty);
 		int old_flow = ((old_termios->c_iflag & IXON) &&
 				(old_termios->c_cc[VSTOP] == '\023') &&
 				(old_termios->c_cc[VSTART] == '\021'));
@@ -401,13 +403,8 @@ static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,
 	if (legacy) {
 		/* We always use new tty termios data so we can do this
 		   the easy way .. */
-		retval = tty_init_termios(tty);
-		if (retval)
-			goto err_deinit_tty;
-
-		retval = tty_init_termios(o_tty);
-		if (retval)
-			goto err_free_termios;
+		tty_init_termios(tty);
+		tty_init_termios(o_tty);
 
 		driver->other->ttys[idx] = o_tty;
 		driver->ttys[idx] = tty;
@@ -439,12 +436,7 @@ static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,
 	tty->count++;
 	o_tty->count++;
 	return 0;
-err_free_termios:
-	if (legacy)
-		tty_free_termios(tty);
-err_deinit_tty:
-	deinitialize_tty_struct(o_tty);
-	free_tty_struct(o_tty);
+
 err_put_module:
 	module_put(driver->other->owner);
 err:
@@ -495,6 +487,10 @@ static int pty_bsd_ioctl(struct tty_struct *tty,
 }
 
 static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
+/*
+ * not really modular, but the easiest way to keep compat with existing
+ * bootargs behaviour is to continue using module_param here.
+ */
 module_param(legacy_count, int, 0);
 
 /*
@@ -628,7 +624,7 @@ static int pty_unix98_ioctl(struct tty_struct *tty,
  */
 
 static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
-		struct inode *ptm_inode, int idx)
+		struct file *file, int idx)
 {
 	/* Master must be open via /dev/ptmx */
 	return ERR_PTR(-EIO);
@@ -644,12 +640,12 @@ static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
  */
 
 static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
-		struct inode *pts_inode, int idx)
+		struct file *file, int idx)
 {
 	struct tty_struct *tty;
 
 	mutex_lock(&devpts_mutex);
-	tty = devpts_get_priv(pts_inode);
+	tty = devpts_get_priv(file->f_path.dentry);
 	mutex_unlock(&devpts_mutex);
 	/* Master must be open before slave */
 	if (!tty)
@@ -657,22 +653,25 @@ static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
 	return tty;
 }
 
-/* We have no need to install and remove our tty objects as devpts does all
-   the work for us */
-
 static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
 {
 	return pty_common_install(driver, tty, false);
 }
 
+/* this is called once with whichever end is closed last */
 static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
 {
-}
+	struct pts_fs_info *fsi;
 
-/* this is called once with whichever end is closed last */
-static void pty_unix98_shutdown(struct tty_struct *tty)
-{
-	devpts_kill_index(tty->driver_data, tty->index);
+	if (tty->driver->subtype == PTY_TYPE_MASTER)
+		fsi = tty->driver_data;
+	else
+		fsi = tty->link->driver_data;
+
+	if (fsi) {
+		devpts_kill_index(fsi, tty->index);
+		devpts_release(fsi);
+	}
 }
 
 static const struct tty_operations ptm_unix98_ops = {
@@ -688,7 +687,6 @@ static const struct tty_operations ptm_unix98_ops = {
 	.unthrottle = pty_unthrottle,
 	.ioctl = pty_unix98_ioctl,
 	.resize = pty_resize,
-	.shutdown = pty_unix98_shutdown,
 	.cleanup = pty_cleanup
 };
 
@@ -706,7 +704,6 @@ static const struct tty_operations pty_unix98_ops = {
 	.set_termios = pty_set_termios,
 	.start = pty_start,
 	.stop = pty_stop,
-	.shutdown = pty_unix98_shutdown,
 	.cleanup = pty_cleanup,
 };
 
@@ -724,8 +721,9 @@ static const struct tty_operations pty_unix98_ops = {
 
 static int ptmx_open(struct inode *inode, struct file *filp)
 {
+	struct pts_fs_info *fsi;
 	struct tty_struct *tty;
-	struct inode *slave_inode;
+	struct dentry *dentry;
 	int retval;
 	int index;
 
@@ -738,57 +736,66 @@ static int ptmx_open(struct inode *inode, struct file *filp)
 	if (retval)
 		return retval;
 
-	/* find a device that is not in use. */
-	mutex_lock(&devpts_mutex);
-	index = devpts_new_index(inode);
-	if (index < 0) {
-		retval = index;
-		mutex_unlock(&devpts_mutex);
-		goto err_file;
+	fsi = devpts_acquire(filp);
+	if (IS_ERR(fsi)) {
+		retval = PTR_ERR(fsi);
+		goto out_free_file;
 	}
 
+	/* find a device that is not in use. */
+	mutex_lock(&devpts_mutex);
+	index = devpts_new_index(fsi);
 	mutex_unlock(&devpts_mutex);
 
-	mutex_lock(&tty_mutex);
-	tty = tty_init_dev(ptm_driver, index);
+	retval = index;
+	if (index < 0)
+		goto out_put_fsi;
 
-	if (IS_ERR(tty)) {
-		retval = PTR_ERR(tty);
-		goto out;
-	}
 
+	mutex_lock(&tty_mutex);
+	tty = tty_init_dev(ptm_driver, index);
 	/* The tty returned here is locked so we can safely
 	   drop the mutex */
 	mutex_unlock(&tty_mutex);
 
+	retval = PTR_ERR(tty);
+	if (IS_ERR(tty))
+		goto out;
+
+	/*
+	 * From here on out, the tty is "live", and the index and
+	 * fsi will be killed/put by the tty_release()
+	 */
 	set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
-	tty->driver_data = inode;
+	tty->driver_data = fsi;
 
 	tty_add_file(tty, filp);
 
-	slave_inode = devpts_pty_new(inode,
-			MKDEV(UNIX98_PTY_SLAVE_MAJOR, index), index,
-			tty->link);
-	if (IS_ERR(slave_inode)) {
-		retval = PTR_ERR(slave_inode);
+	dentry = devpts_pty_new(fsi, index, tty->link);
+	if (IS_ERR(dentry)) {
+		retval = PTR_ERR(dentry);
 		goto err_release;
 	}
-	tty->link->driver_data = slave_inode;
+	tty->link->driver_data = dentry;
 
 	retval = ptm_driver->ops->open(tty, filp);
 	if (retval)
 		goto err_release;
 
+	tty_debug_hangup(tty, "opening (count=%d)\n", tty->count);
+
 	tty_unlock(tty);
 	return 0;
 err_release:
 	tty_unlock(tty);
+	// This will also put-ref the fsi
 	tty_release(inode, filp);
 	return retval;
 out:
-	mutex_unlock(&tty_mutex);
-	devpts_kill_index(inode, index);
-err_file:
+	devpts_kill_index(fsi, index);
+out_put_fsi:
+	devpts_release(fsi);
+out_free_file:
 	tty_free_file(filp);
 	return retval;
 }
@@ -869,4 +876,4 @@ static int __init pty_init(void)
 	unix98_pty_init();
 	return 0;
 }
-module_init(pty_init);
+device_initcall(pty_init);