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TTY: rfcomm/tty, use count from tty_port
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This means converting an atomic counter to a counter protected by
lock. This is the first step needed to convert the rest of the code to
the tty_port helpers.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Jiri Slaby authored and Greg Kroah-Hartman committed Apr 9, 2012
1 parent b2c4be3 commit f997a01
Showing 1 changed file with 21 additions and 9 deletions.
30 changes: 21 additions & 9 deletions net/bluetooth/rfcomm/tty.c
Original file line number Diff line number Diff line change
Expand Up @@ -54,7 +54,6 @@ struct rfcomm_dev {
char name[12];
int id;
unsigned long flags;
atomic_t opened;
int err;

bdaddr_t src;
Expand Down Expand Up @@ -240,8 +239,6 @@ static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
dev->flags = req->flags &
((1 << RFCOMM_RELEASE_ONHUP) | (1 << RFCOMM_REUSE_DLC));

atomic_set(&dev->opened, 0);

tty_port_init(&dev->port);
dev->port.ops = &rfcomm_port_ops;
init_waitqueue_head(&dev->wait);
Expand Down Expand Up @@ -311,12 +308,17 @@ static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)

static void rfcomm_dev_del(struct rfcomm_dev *dev)
{
unsigned long flags;
BT_DBG("dev %p", dev);

BUG_ON(test_and_set_bit(RFCOMM_TTY_RELEASED, &dev->flags));

if (atomic_read(&dev->opened) > 0)
spin_lock_irqsave(&dev->port.lock, flags);
if (dev->port.count > 0) {
spin_unlock_irqrestore(&dev->port.lock, flags);
return;
}
spin_unlock_irqrestore(&dev->port.lock, flags);

spin_lock(&rfcomm_dev_lock);
list_del_init(&dev->list);
Expand Down Expand Up @@ -651,6 +653,7 @@ static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
DECLARE_WAITQUEUE(wait, current);
struct rfcomm_dev *dev;
struct rfcomm_dlc *dlc;
unsigned long flags;
int err, id;

id = tty->index;
Expand All @@ -666,10 +669,14 @@ static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
return -ENODEV;

BT_DBG("dev %p dst %s channel %d opened %d", dev, batostr(&dev->dst),
dev->channel, atomic_read(&dev->opened));
dev->channel, dev->port.count);

if (atomic_inc_return(&dev->opened) > 1)
spin_lock_irqsave(&dev->port.lock, flags);
if (++dev->port.count > 1) {
spin_unlock_irqrestore(&dev->port.lock, flags);
return 0;
}
spin_unlock_irqrestore(&dev->port.lock, flags);

dlc = dev->dlc;

Expand Down Expand Up @@ -724,13 +731,17 @@ static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
{
struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
unsigned long flags;

if (!dev)
return;

BT_DBG("tty %p dev %p dlc %p opened %d", tty, dev, dev->dlc,
atomic_read(&dev->opened));
dev->port.count);

if (atomic_dec_and_test(&dev->opened)) {
spin_lock_irqsave(&dev->port.lock, flags);
if (!--dev->port.count) {
spin_unlock_irqrestore(&dev->port.lock, flags);
if (dev->tty_dev->parent)
device_move(dev->tty_dev, NULL, DPM_ORDER_DEV_LAST);

Expand All @@ -751,7 +762,8 @@ static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)

tty_port_put(&dev->port);
}
}
} else
spin_unlock_irqrestore(&dev->port.lock, flags);

tty_port_put(&dev->port);
}
Expand Down

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