diff options
| -rw-r--r-- | drivers/char/pty.c | 49 | ||||
| -rw-r--r-- | drivers/char/tty_io.c | 64 | ||||
| -rw-r--r-- | include/linux/tty_driver.h | 9 |
3 files changed, 81 insertions, 41 deletions
diff --git a/drivers/char/pty.c b/drivers/char/pty.c index 328e8ac..6e148ad 100644 --- 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 a540849..ac41af8 100644 --- 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 2322313..2c5c35c 100644 --- 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); |