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>

1 files changed, 6 insertions, 2 deletions

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);