From: Peter Hurley <peter@hurleysoftware.com>
Date: Thu, 16 Oct 2014 17:54:36 +0000 (-0400)
Subject: tty: Prevent "read/write wait queue active!" log flooding
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=494c1eac7e73f719af9d474a96ec8494c33efd6a;p=sagit-ice-cold%2Fkernel_xiaomi_msm8998.git

tty: Prevent "read/write wait queue active!" log flooding

Only print one warning when a task is on the read_wait or write_wait
wait queue at final tty release.

Cc: <stable@vger.kernel.org> # 3.4.x+
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 4021c10d9908..0508a1d8e4cd 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1710,6 +1710,7 @@ int tty_release(struct inode *inode, struct file *filp)
 	int	idx;
 	char	buf[64];
 	long	timeout = 0;
+	int	once = 1;
 
 	if (tty_paranoia_check(tty, inode, __func__))
 		return 0;
@@ -1790,8 +1791,11 @@ int tty_release(struct inode *inode, struct file *filp)
 		if (!do_sleep)
 			break;
 
-		printk(KERN_WARNING "%s: %s: read/write wait queue active!\n",
-				__func__, tty_name(tty, buf));
+		if (once) {
+			once = 0;
+			printk(KERN_WARNING "%s: %s: read/write wait queue active!\n",
+			       __func__, tty_name(tty, buf));
+		}
 		tty_unlock_pair(tty, o_tty);
 		mutex_unlock(&tty_mutex);
 		schedule_timeout_killable(timeout);