spin_unlock(&tty->files_lock);
}
-/**
+/*
* tty_free_file - free file->private_data
*
* This shall be used only for fail path handling when tty_add_file was not
static DEFINE_SPINLOCK(redirect_lock);
static struct file *redirect;
-extern void tty_sysctl_init(void);
-
/**
* tty_wakeup - request more data
* @tty: terminal
EXPORT_SYMBOL_GPL(tty_wakeup);
+/**
+ * tty_release_redirect - Release a redirect on a pty if present
+ * @tty: tty device
+ *
+ * This is available to the pty code so if the master closes, if the
+ * slave is a redirect it can release the redirect. It returns the
+ * filp for the redirect, which must be fput when the operations on
+ * the tty are completed.
+ */
+struct file *tty_release_redirect(struct tty_struct *tty)
+{
+ struct file *f = NULL;
+
+ spin_lock(&redirect_lock);
+ if (redirect && file_tty(redirect) == tty) {
+ f = redirect;
+ redirect = NULL;
+ }
+ spin_unlock(&redirect_lock);
+
+ return f;
+}
+
/**
* __tty_hangup - actual handler for hangup events
* @tty: tty device
+ * @exit_session: if non-zero, signal all foreground group processes
*
* This can be called by a "kworker" kernel thread. That is process
* synchronous but doesn't hold any locks, so we need to make sure we
static void __tty_hangup(struct tty_struct *tty, int exit_session)
{
struct file *cons_filp = NULL;
- struct file *filp, *f = NULL;
+ struct file *filp, *f;
struct tty_file_private *priv;
int closecount = 0, n;
int refs;
if (!tty)
return;
-
- spin_lock(&redirect_lock);
- if (redirect && file_tty(redirect) == tty) {
- f = redirect;
- redirect = NULL;
- }
- spin_unlock(&redirect_lock);
+ f = tty_release_redirect(tty);
tty_lock(tty);
return tty_write(iocb, iter);
}
-/**
+/*
* tty_send_xchar - send priority character
*
* Send a high priority character to the tty even if stopped
/**
* tty_driver_lookup_tty() - find an existing tty, if any
* @driver: the driver for the tty
+ * @file: file object
* @idx: the minor number
*
* Return the tty, if found. If not found, return NULL or ERR_PTR() if the
/**
* release_tty - release tty structure memory
+ * @tty: tty device release
+ * @idx: index of the tty device release
*
* Release both @tty and a possible linked partner (think pty pair),
* and decrement the refcount of the backing module.
return driver;
}
-/**
- * tty_kopen - open a tty device for kernel
- * @device: dev_t of device to open
- *
- * Opens tty exclusively for kernel. Performs the driver lookup,
- * makes sure it's not already opened and performs the first-time
- * tty initialization.
- *
- * Returns the locked initialized &tty_struct
- *
- * Claims the global tty_mutex to serialize:
- * - concurrent first-time tty initialization
- * - concurrent tty driver removal w/ lookup
- * - concurrent tty removal from driver table
- */
-struct tty_struct *tty_kopen(dev_t device)
+static struct tty_struct *tty_kopen(dev_t device, int shared)
{
struct tty_struct *tty;
struct tty_driver *driver;
/* check whether we're reopening an existing tty */
tty = tty_driver_lookup_tty(driver, NULL, index);
- if (IS_ERR(tty))
+ if (IS_ERR(tty) || shared)
goto out;
if (tty) {
tty_driver_kref_put(driver);
return tty;
}
-EXPORT_SYMBOL_GPL(tty_kopen);
+
+/**
+ * tty_kopen_exclusive - open a tty device for kernel
+ * @device: dev_t of device to open
+ *
+ * Opens tty exclusively for kernel. Performs the driver lookup,
+ * makes sure it's not already opened and performs the first-time
+ * tty initialization.
+ *
+ * Returns the locked initialized &tty_struct
+ *
+ * Claims the global tty_mutex to serialize:
+ * - concurrent first-time tty initialization
+ * - concurrent tty driver removal w/ lookup
+ * - concurrent tty removal from driver table
+ */
+struct tty_struct *tty_kopen_exclusive(dev_t device)
+{
+ return tty_kopen(device, 0);
+}
+EXPORT_SYMBOL_GPL(tty_kopen_exclusive);
+
+/**
+ * tty_kopen_shared - open a tty device for shared in-kernel use
+ * @device: dev_t of device to open
+ *
+ * Opens an already existing tty for in-kernel use. Compared to
+ * tty_kopen_exclusive() above it doesn't ensure to be the only user.
+ *
+ * Locking is identical to tty_kopen() above.
+ */
+struct tty_struct *tty_kopen_shared(dev_t device)
+{
+ return tty_kopen(device, 1);
+}
+EXPORT_SYMBOL_GPL(tty_kopen_shared);
/**
* tty_open_by_driver - open a tty device
return tty->ops->tiocmset(tty, set, clear);
}
+/**
+ * tty_get_icount - get tty statistics
+ * @tty: tty device
+ * @icount: output parameter
+ *
+ * Gets a copy of the tty's icount statistics.
+ *
+ * Locking: none (up to the driver)
+ */
+int tty_get_icount(struct tty_struct *tty,
+ struct serial_icounter_struct *icount)
+{
+ memset(icount, 0, sizeof(*icount));
+
+ if (tty->ops->get_icount)
+ return tty->ops->get_icount(tty, icount);
+ else
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(tty_get_icount);
+
static int tty_tiocgicount(struct tty_struct *tty, void __user *arg)
{
- int retval = -EINVAL;
struct serial_icounter_struct icount;
- memset(&icount, 0, sizeof(icount));
- if (tty->ops->get_icount)
- retval = tty->ops->get_icount(tty, &icount);
+ int retval;
+
+ retval = tty_get_icount(tty, &icount);
if (retval != 0)
return retval;
+
if (copy_to_user(arg, &icount, sizeof(icount)))
return -EFAULT;
return 0;
}
-/**
+/*
* alloc_tty_struct
*
* This subroutine allocates and initializes a tty structure.
git.samba.org / sfrench / cifs-2.6.git / blobdiff