Commit 0bfd464d authored by Peter Hurley's avatar Peter Hurley Committed by Greg Kroah-Hartman

tty: Wait interruptibly for tty lock on reopen

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: default avatarPeter Hurley <peter@hurleysoftware.com>
Cc: stable <stable@vger.kernel.org> # 4.4
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 92e963f5
...@@ -2065,7 +2065,12 @@ static int tty_open(struct inode *inode, struct file *filp) ...@@ -2065,7 +2065,12 @@ static int tty_open(struct inode *inode, struct file *filp)
if (tty) { if (tty) {
mutex_unlock(&tty_mutex); 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() */ /* safe to drop the kref from tty_driver_lookup_tty() */
tty_kref_put(tty); tty_kref_put(tty);
retval = tty_reopen(tty); retval = tty_reopen(tty);
...@@ -2152,6 +2157,7 @@ static int tty_open(struct inode *inode, struct file *filp) ...@@ -2152,6 +2157,7 @@ static int tty_open(struct inode *inode, struct file *filp)
return 0; return 0;
err_unlock: err_unlock:
mutex_unlock(&tty_mutex); mutex_unlock(&tty_mutex);
err_unref:
/* after locks to avoid deadlock */ /* after locks to avoid deadlock */
if (!IS_ERR_OR_NULL(driver)) if (!IS_ERR_OR_NULL(driver))
tty_driver_kref_put(driver); tty_driver_kref_put(driver);
......
...@@ -19,6 +19,14 @@ void __lockfunc tty_lock(struct tty_struct *tty) ...@@ -19,6 +19,14 @@ void __lockfunc tty_lock(struct tty_struct *tty)
} }
EXPORT_SYMBOL(tty_lock); 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 __lockfunc tty_unlock(struct tty_struct *tty) void __lockfunc tty_unlock(struct tty_struct *tty)
{ {
if (WARN(tty->magic != TTY_MAGIC, "U Bad %p\n", tty)) if (WARN(tty->magic != TTY_MAGIC, "U Bad %p\n", tty))
......
...@@ -649,6 +649,7 @@ extern long vt_compat_ioctl(struct tty_struct *tty, ...@@ -649,6 +649,7 @@ extern long vt_compat_ioctl(struct tty_struct *tty,
/* tty_mutex.c */ /* tty_mutex.c */
/* functions for preparation of BKL removal */ /* functions for preparation of BKL removal */
extern void __lockfunc tty_lock(struct tty_struct *tty); extern void __lockfunc tty_lock(struct tty_struct *tty);
extern int tty_lock_interruptible(struct tty_struct *tty);
extern void __lockfunc tty_unlock(struct tty_struct *tty); extern void __lockfunc tty_unlock(struct tty_struct *tty);
extern void __lockfunc tty_lock_slave(struct tty_struct *tty); extern void __lockfunc tty_lock_slave(struct tty_struct *tty);
extern void __lockfunc tty_unlock_slave(struct tty_struct *tty); extern void __lockfunc tty_unlock_slave(struct tty_struct *tty);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment