| From | Peter Hurley <> | Subject | [PATCH -next 10/27] tty: Don't take tty_mutex for tty count changes | Date | Thu, 16 Oct 2014 16:25:08 -0400 |
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Holding tty_mutex is no longer required to serialize changes to the tty_count or to prevent concurrent opens of closing ttys; tty_lock() is sufficient.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> --- drivers/tty/tty_io.c | 6 ------ 1 file changed, 6 deletions(-)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 55f9931..7b40247 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1805,10 +1805,6 @@ int tty_release(struct inode *inode, struct file *filp) * each iteration we avoid any problems. */ while (1) { - /* Guard against races with tty->count changes elsewhere and - opens on /dev/tty */ - - mutex_lock(&tty_mutex); tty_lock_pair(tty, o_tty); tty_closing = tty->count <= 1; o_tty_closing = o_tty && @@ -1844,7 +1840,6 @@ int tty_release(struct inode *inode, struct file *filp) __func__, tty_name(tty, buf)); } tty_unlock_pair(tty, o_tty); - mutex_unlock(&tty_mutex); schedule_timeout_killable(timeout); if (timeout < 120 * HZ) timeout = 2 * timeout + 1; @@ -1899,7 +1894,6 @@ int tty_release(struct inode *inode, struct file *filp) read_unlock(&tasklist_lock); } - mutex_unlock(&tty_mutex); tty_unlock_pair(tty, o_tty); /* At this point, the tty->count == 0 should ensure a dead tty cannot be re-opened by a racing opener */ -- 2.1.1
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