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Date: Tue, 20 Mar 2007 19:42:54 +0000 (GMT)
From: Hugh Dickins <hugh@veritas.com>
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To: Andrew Morton <akpm@linux-foundation.org>
cc: "Eric W. Biederman" <ebiederm@xmission.com>, linux-kernel@vger.kernel.org
Subject: 2.6.21-rc4-mm1: init hangs on tty_mutex
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I get a hang at startup or shutdown: tiocsctty() holds tty_mutex, and
now with Eric's tty-in-tiocsctty-when-we-steal-a-tty-hang-it-up.patch
it can end up calling con_close(), which tries to take tty_mutex.
So best revert that in hot-fixes, until Eric provides a better.

Signed-off-by: Hugh Dickins <hugh@veritas.com>

--- 2.6.21-rc4-mm1/drivers/char/tty_io.c	2007-03-20 12:49:34.000000000 +0000
+++ linux/drivers/char/tty_io.c	2007-03-20 18:14:53.000000000 +0000
@@ -2980,7 +2980,9 @@ static int tiocsctty(struct tty_struct *
 			/*
 			 * Steal it away
 			 */
-			tty_vhangup(tty);
+			read_lock(&tasklist_lock);
+			session_clear_tty(tty->session);
+			read_unlock(&tasklist_lock);
 		} else {
 			ret = -EPERM;
 			goto unlock;