From: Peter Hurley <peter@hurleysoftware.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>,
linux-kernel@vger.kernel.org,
Peter Hurley <peter@hurleysoftware.com>
Subject: [PATCH 07/12] tty: Wait interruptibly for tty lock on reopen
Date: Fri, 27 Nov 2015 21:25:52 -0500 [thread overview]
Message-ID: <1448677557-16420-8-git-send-email-peter@hurleysoftware.com> (raw)
In-Reply-To: <1448677557-16420-1-git-send-email-peter@hurleysoftware.com>
Allow a signal to interrupt the wait for a tty reopen; eg., if
the tty has starting final close and is waiting for the device to
drain.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
---
drivers/tty/tty_io.c | 8 +++++++-
drivers/tty/tty_mutex.c | 8 ++++++++
include/linux/tty.h | 1 +
3 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 64978ca..afd378e 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2064,7 +2064,12 @@ retry_open:
if (tty) {
mutex_unlock(&tty_mutex);
- tty_lock(tty);
+ retval = tty_lock_interruptible(tty);
+ if (retval) {
+ if (retval == -EINTR)
+ retval = -ERESTARTSYS;
+ goto err_unref;
+ }
/* safe to drop the kref from tty_driver_lookup_tty() */
tty_kref_put(tty);
retval = tty_reopen(tty);
@@ -2151,6 +2156,7 @@ retry_open:
return 0;
err_unlock:
mutex_unlock(&tty_mutex);
+err_unref:
/* after locks to avoid deadlock */
if (!IS_ERR_OR_NULL(driver))
tty_driver_kref_put(driver);
diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c
index 79dac6f..75351e4 100644
--- a/drivers/tty/tty_mutex.c
+++ b/drivers/tty/tty_mutex.c
@@ -19,6 +19,14 @@ void tty_lock(struct tty_struct *tty)
}
EXPORT_SYMBOL(tty_lock);
+int tty_lock_interruptible(struct tty_struct *tty)
+{
+ if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
+ return -EIO;
+ tty_kref_get(tty);
+ return mutex_lock_interruptible(&tty->legacy_mutex);
+}
+
void tty_unlock(struct tty_struct *tty)
{
if (WARN(tty->magic != TTY_MAGIC, "U Bad %p\n", tty))
diff --git a/include/linux/tty.h b/include/linux/tty.h
index c3ea90a..c7c5d3c 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -645,6 +645,7 @@ extern long vt_compat_ioctl(struct tty_struct *tty,
/* tty_mutex.c */
/* functions for preparation of BKL removal */
extern void tty_lock(struct tty_struct *tty);
+extern int tty_lock_interruptible(struct tty_struct *tty);
extern void tty_unlock(struct tty_struct *tty);
extern void tty_lock_slave(struct tty_struct *tty);
extern void tty_unlock_slave(struct tty_struct *tty);
--
2.6.3
next prev parent reply other threads:[~2015-11-28 2:26 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-28 2:25 [PATCH 00/12] Rework tty_reopen() Peter Hurley
2015-11-28 2:25 ` [PATCH 01/12] tty: Fix ldisc leak in failed tty_init_dev() Peter Hurley
2015-11-28 2:25 ` [PATCH 02/12] tty: Remove !tty check from free_tty_struct() Peter Hurley
2015-11-28 2:25 ` [PATCH 03/12] tty: Fix tty_init_termios() declaration Peter Hurley
2015-11-28 2:25 ` [PATCH 04/12] tty: Re-declare tty_driver_remove_tty() file scope Peter Hurley
2015-11-28 2:25 ` [PATCH 05/12] pty: Remove pty_unix98_shutdown() Peter Hurley
2015-11-28 2:25 ` [PATCH 06/12] tty: Remove __lockfunc annotation from tty lock functions Peter Hurley
2015-11-28 2:25 ` Peter Hurley [this message]
2015-11-28 2:25 ` [PATCH 08/12] pty: Prepare to redefine tty driver remove() interface Peter Hurley
2015-11-28 2:25 ` [PATCH 09/12] tty: Re-define " Peter Hurley
2015-11-28 2:25 ` [PATCH 10/12] tty: Consolidate noctty checks in tty_open() Peter Hurley
2015-11-28 2:25 ` [PATCH 11/12] tty: Refactor tty_open() Peter Hurley
2015-11-28 2:25 ` [PATCH 12/12] tty: Retry failed reopen if tty teardown in-progress Peter Hurley
2015-12-16 15:43 ` [PATCH 00/12] Rework tty_reopen() Peter Hurley
2015-12-17 5:53 ` Pratyush Anand
2015-12-17 7:15 ` Greg Kroah-Hartman
2016-01-10 5:13 ` [PATCH v2 00/10] " Peter Hurley
2016-01-10 5:13 ` [PATCH v2 01/10] tty: Wait interruptibly for tty lock on reopen Peter Hurley
2016-01-10 5:13 ` [PATCH v2 02/10] tty: Retry failed reopen if tty teardown in-progress Peter Hurley
2016-01-10 5:13 ` [PATCH v2 03/10] tty: Fix ldisc leak in failed tty_init_dev() Peter Hurley
2016-01-10 5:13 ` [PATCH v2 04/10] tty: Remove !tty check from free_tty_struct() Peter Hurley
2016-01-10 5:13 ` [PATCH v2 05/10] tty: Fix tty_init_termios() declaration Peter Hurley
2016-01-19 9:17 ` Johan Hovold
2016-01-10 5:13 ` [PATCH v2 06/10] tty: Re-declare tty_driver_remove_tty() file scope Peter Hurley
2016-01-10 5:13 ` [PATCH v2 07/10] pty: Remove pty_unix98_shutdown() Peter Hurley
2016-01-10 5:13 ` [PATCH v2 08/10] tty: Remove __lockfunc annotation from tty lock functions Peter Hurley
2016-01-10 5:13 ` [PATCH v2 09/10] tty: Consolidate noctty checks in tty_open() Peter Hurley
2016-03-26 17:58 ` Richard Weinberger
2016-03-26 19:06 ` Peter Hurley
2016-03-26 19:14 ` Richard Weinberger
2016-03-26 19:14 ` [uml-devel] " Richard Weinberger
2016-01-10 5:13 ` [PATCH v2 10/10] tty: Refactor tty_open() Peter Hurley
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