tree e8ca124d3b1e01ce592a382572dd962317e3dd61
parent 5d93e748957336de1f28e7356bb43d6da01718bc
author Peter Hurley <peter@hurleysoftware.com> 1415207568 -0500
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1415240650 -0800

tty: Check tty->count instead of TTY_CLOSING in tty_reopen()

Although perhaps not obvious, the TTY_CLOSING bit is set when the
tty count has been decremented to 0 (which occurs while holding
tty_lock). The only other case when tty count is 0 during a re-open
is when a legacy BSD pty master has been opened in parallel but
after the pty slave, which is unsupported and returns an error.

Thus !tty->count contains the complete set of degenerate conditions
under which a tty open fails.

Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>