On 07/22/2013 12:27 PM, Gianluca Anzolin wrote:
Remove the device from rfcomm_dev_list in the tty_port destructor. Signed-off-by: Gianluca Anzolin <gianluca@xxxxxxxxxxxxxx> --- net/bluetooth/rfcomm/tty.c | 27 ++++++--------------------- 1 file changed, 6 insertions(+), 21 deletions(-) diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c index 1258678..17e5faa 100644 --- a/net/bluetooth/rfcomm/tty.c +++ b/net/bluetooth/rfcomm/tty.c @@ -75,13 +75,6 @@ static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig); /* ---- Device functions ---- */ -/* - * The reason this isn't actually a race, as you no doubt have a little voice - * screaming at you in your head, is that the refcount should never actually - * reach zero unless the device has already been taken off the list, in - * rfcomm_dev_del(). And if that's not true, we'll hit the BUG() in - * rfcomm_dev_destruct() anyway. - */ static void rfcomm_dev_destruct(struct tty_port *port) { struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port); @@ -89,10 +82,9 @@ static void rfcomm_dev_destruct(struct tty_port *port) BT_DBG("dev %p dlc %p", dev, dlc); - /* Refcount should only hit zero when called from rfcomm_dev_del() - which will have taken us off the list. Everything else are - refcounting bugs. */ - BUG_ON(!list_empty(&dev->list)); + spin_lock(&rfcomm_dev_lock); + list_del(&dev->list); + spin_unlock(&rfcomm_dev_lock); rfcomm_dlc_lock(dlc); /* Detach DLC if it's owned by this dev */ @@ -295,7 +287,9 @@ out: dev->id, NULL); if (IS_ERR(dev->tty_dev)) { err = PTR_ERR(dev->tty_dev); + spin_lock(&rfcomm_dev_lock); list_del(&dev->list); + spin_unlock(&rfcomm_dev_lock); goto free; } @@ -328,10 +322,6 @@ static void rfcomm_dev_del(struct rfcomm_dev *dev) } spin_unlock_irqrestore(&dev->port.lock, flags); - spin_lock(&rfcomm_dev_lock); - list_del_init(&dev->list); - spin_unlock(&rfcomm_dev_lock); - tty_port_put(&dev->port); } @@ -753,13 +743,8 @@ static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp) tty_port_close(&dev->port, tty, filp); - if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags)) { - spin_lock(&rfcomm_dev_lock); - list_del_init(&dev->list); - spin_unlock(&rfcomm_dev_lock); -
Gianluca, I think you may have missed my comment that this patch should be earlier in the series. That way you wouldn't be adding code in 4/7 that you're removing here. Regards, Peter Hurley
+ if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags)) tty_port_put(&dev->port); - } } static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
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