tty: Clean up the tty_init_dev changes further

Fix up the naming, style and extract some bits of code into the driver
specific code

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/char/pty.c b/drivers/char/pty.c
index 328e8ac1230667d5b8b015dfa65c541279311505..6e148ade7353ff7f6c4787ebf13113fe574cec87 100644 (file)
--- a/drivers/char/pty.c
+++ b/drivers/char/pty.c
@@ -391,6 +391,41 @@ static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file,
        return -ENOIOCTLCMD;
 }
 
+/**
+ *     ptm_unix98_lookup       -       find a pty master
+ *     @driver: ptm driver
+ *     @idx: tty index
+ *
+ *     Look up a pty master device. Called under the tty_mutex for now.
+ *     This provides our locking.
+ */
+
+static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, int idx)
+{
+       struct tty_struct *tty = devpts_get_tty(idx);
+       if (tty)
+               tty = tty->link;
+       return tty;
+}
+
+/**
+ *     pts_unix98_lookup       -       find a pty slave
+ *     @driver: pts driver
+ *     @idx: tty index
+ *
+ *     Look up a pty master device. Called under the tty_mutex for now.
+ *     This provides our locking.
+ */
+
+static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, int idx)
+{
+       struct tty_struct *tty = devpts_get_tty(idx);
+       /* Master must be open before slave */
+       if (!tty)
+               return ERR_PTR(-EIO);
+       return tty;
+}
+
 static void pty_shutdown(struct tty_struct *tty)
 {
        /* We have our own method as we don't use the tty index */
@@ -399,6 +434,7 @@ static void pty_shutdown(struct tty_struct *tty)
 }
 
 static const struct tty_operations ptm_unix98_ops = {
+       .lookup = ptm_unix98_lookup,
        .open = pty_open,
        .close = pty_close,
        .write = pty_write,
@@ -411,6 +447,17 @@ static const struct tty_operations ptm_unix98_ops = {
        .shutdown = pty_shutdown
 };
 
+static const struct tty_operations pty_unix98_ops = {
+       .lookup = pts_unix98_lookup,
+       .open = pty_open,
+       .close = pty_close,
+       .write = pty_write,
+       .write_room = pty_write_room,
+       .flush_buffer = pty_flush_buffer,
+       .chars_in_buffer = pty_chars_in_buffer,
+       .unthrottle = pty_unthrottle,
+       .set_termios = pty_set_termios,
+};
 
 /**
  *     ptmx_open               -       open a unix 98 pty master
@@ -517,7 +564,7 @@ static void __init unix98_pty_init(void)
        pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
                TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
        pts_driver->other = ptm_driver;
-       tty_set_operations(pts_driver, &pty_ops);
+       tty_set_operations(pts_driver, &pty_unix98_ops);
        
        if (tty_register_driver(ptm_driver))
                panic("Couldn't register Unix98 ptm driver");

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index a5408496d30154faf9c8ade57804129e871bc3d3..ac41af8763d142a479ae2424d55d5864299e38ae 100644 (file)
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -1204,53 +1204,38 @@ static void tty_line_name(struct tty_driver *driver, int index, char *p)
        sprintf(p, "%s%d", driver->name, index + driver->name_base);
 }
 
-/*
- *     find_tty() - find an existing tty, if any
- *     @driver: the driver for the tty
- *     @idx:    the minor number
+/**
+ *     tty_driver_lookup_tty() - find an existing tty, if any
+ *     @driver: the driver for the tty
+ *     @idx:    the minor number
  *
- *     Return the tty, if found or ERR_PTR() otherwise.
+ *     Return the tty, if found or ERR_PTR() otherwise.
  *
- *     Locking: tty_mutex must be held. If tty is found, the mutex must
- *              be held until the 'fast-open' is also done.
+ *     Locking: tty_mutex must be held. If tty is found, the mutex must
+ *     be held until the 'fast-open' is also done. Will change once we
+ *     have refcounting in the driver and per driver locking
  */
-struct tty_struct *find_tty(struct tty_driver *driver, int idx)
+struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, int idx)
 {
        struct tty_struct *tty;
 
-       /* check whether we're reopening an existing tty */
-       if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
-               tty = devpts_get_tty(idx);
-               /*
-                * If we don't have a tty here on a slave open, it's because
-                * the master already started the close process and there's
-                * no relation between devpts file and tty anymore.
-                */
-               if (!tty && driver->subtype == PTY_TYPE_SLAVE)
-                       return ERR_PTR(-EIO);
+       if (driver->ops->lookup)
+               return driver->ops->lookup(driver, idx);
 
-               /*
-                * tty is safe on because we are called with tty_mutex held
-                * and release_dev() won't change tty->count or tty->flags
-                * without grabbing tty_mutex.
-                */
-               if (tty && driver->subtype == PTY_TYPE_MASTER)
-                       tty = tty->link;
-       } else
                tty = driver->ttys[idx];
        return tty;
 }
 
-/*
- *     fast_tty_open() - fast re-open of an open tty
- *     @tty    - the tty to open
+/**
+ *     tty_reopen()    - fast re-open of an open tty
+ *     @tty    - the tty to open
  *
- *     Return 0 on success, -errno on error.
+ *     Return 0 on success, -errno on error.
  *
- *     Locking: tty_mutex must be held from the time the tty was found
- *              till this open completes.
+ *     Locking: tty_mutex must be held from the time the tty was found
+ *              till this open completes.
  */
-static int fast_tty_open(struct tty_struct *tty)
+static int tty_reopen(struct tty_struct *tty)
 {
        struct tty_driver *driver = tty->driver;
 
@@ -1271,9 +1256,7 @@ static int fast_tty_open(struct tty_struct *tty)
        tty->count++;
        tty->driver = driver; /* N.B. why do this every time?? */
 
-       /* FIXME */
-       if (!test_bit(TTY_LDISC, &tty->flags))
-               printk(KERN_ERR "fast_tty_open: no ldisc\n");
+       WARN_ON(!test_bit(TTY_LDISC, &tty->flags));
 
        return 0;
 }
@@ -1312,14 +1295,14 @@ int tty_init_dev(struct tty_driver *driver, int idx,
        int retval = 0;
 
        /* check whether we're reopening an existing tty */
-       tty = find_tty(driver, idx);
+       tty = tty_driver_lookup_tty(driver, idx);
        if (IS_ERR(tty)) {
                retval = PTR_ERR(tty);
                goto end_init;
        }
 
        if (tty) {
-               retval = fast_tty_open(tty);
+               retval = tty_reopen(tty);
                if (retval)
                        return retval;
                *ret_tty = tty;
@@ -1440,6 +1423,8 @@ int tty_init_dev(struct tty_driver *driver, int idx,
         * All structures have been allocated, so now we install them.
         * Failures after this point use release_tty to clean up, so
         * there's no need to null out the local pointers.
+        *
+        * FIXME: We want a 'driver->install method ?
         */
        if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM))
                driver->ttys[idx] = tty;
@@ -1466,9 +1451,8 @@ int tty_init_dev(struct tty_driver *driver, int idx,
 
        if (retval)
                goto release_mem_out;
-success:
-       *ret_tty = tty;
 
+       *ret_tty = tty;
        /* All paths come through here to release the mutex */
 end_init:
        return retval;

diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index 2322313a8589d614c84275d020f0ad1a33d9ad41..2c5c35c4656fd7c18b7edcf4419425a7a0de78e6 100644 (file)
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -7,6 +7,14 @@
  * defined; unless noted otherwise, they are optional, and can be
  * filled in with a null pointer.
  *
+ * struct tty_struct * (*lookup)(struct tty_driver *self, int idx)
+ *
+ *     Return the tty device corresponding to idx, NULL if there is not
+ *     one currently in use and an ERR_PTR value on error. Called under
+ *     tty_mutex (for now!)
+ *
+ *     Optional method. Default behaviour is to use the ttys array
+ *
  * int  (*open)(struct tty_struct * tty, struct file * filp);
  *
  *     This routine is called when a particular tty device is opened.
@@ -203,6 +211,7 @@ struct tty_struct;
 struct tty_driver;
 
 struct tty_operations {
+       struct tty_struct * (*lookup)(struct tty_driver *driver, int idx);
        int  (*open)(struct tty_struct * tty, struct file * filp);
        void (*close)(struct tty_struct * tty, struct file * filp);
        void (*shutdown)(struct tty_struct *tty);