Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759205AbYJEQXg (ORCPT ); Sun, 5 Oct 2008 12:23:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758683AbYJEQUm (ORCPT ); Sun, 5 Oct 2008 12:20:42 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:57947 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758673AbYJEQUk (ORCPT ); Sun, 5 Oct 2008 12:20:40 -0400 From: Alan Cox Subject: [PATCH 51/76] tty: kref the tty driver object To: linux-kernel@vger.kernel.org Date: Sun, 05 Oct 2008 17:20:40 +0100 Message-ID: <20081005161937.1997.39297.stgit@localhost.localdomain> In-Reply-To: <20081005160231.1997.10462.stgit@localhost.localdomain> References: <20081005160231.1997.10462.stgit@localhost.localdomain> User-Agent: StGIT/0.14.2 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10934 Lines: 365 Signed-off-by: Alan Cox --- drivers/char/ip2/ip2main.c | 6 +- drivers/char/pty.c | 5 ++ drivers/char/tty_io.c | 110 ++++++++++++++++++++++++-------------------- drivers/net/wan/Kconfig | 2 - include/linux/tty_driver.h | 15 ++++-- 5 files changed, 80 insertions(+), 58 deletions(-) diff --git a/drivers/char/ip2/ip2main.c b/drivers/char/ip2/ip2main.c index 66f52a2..6774572 100644 --- a/drivers/char/ip2/ip2main.c +++ b/drivers/char/ip2/ip2main.c @@ -264,8 +264,8 @@ static int tracewrap; /**********/ #if defined(MODULE) && defined(IP2DEBUG_OPEN) -#define DBG_CNT(s) printk(KERN_DEBUG "(%s): [%x] refc=%d, ttyc=%d, modc=%x -> %s\n", \ - tty->name,(pCh->flags),ip2_tty_driver->refcount, \ +#define DBG_CNT(s) printk(KERN_DEBUG "(%s): [%x] ttyc=%d, modc=%x -> %s\n", \ + tty->name,(pCh->flags), \ tty->count,/*GET_USE_COUNT(module)*/0,s) #else #define DBG_CNT(s) @@ -2893,7 +2893,7 @@ ip2_ipl_ioctl (struct file *pFile, UINT cmd, ULONG arg ) case 13: switch ( cmd ) { case 64: /* Driver - ip2stat */ - rc = put_user(ip2_tty_driver->refcount, pIndex++ ); + rc = put_user(-1, pIndex++ ); rc = put_user(irq_counter, pIndex++ ); rc = put_user(bh_counter, pIndex++ ); break; diff --git a/drivers/char/pty.c b/drivers/char/pty.c index 6e148ad..0fdfa05 100644 --- a/drivers/char/pty.c +++ b/drivers/char/pty.c @@ -571,8 +571,11 @@ static void __init unix98_pty_init(void) if (tty_register_driver(pts_driver)) panic("Couldn't register Unix98 pts driver"); + /* FIXME: WTF */ +#if 0 pty_table[1].data = &ptm_driver->refcount; - register_sysctl_table(pty_root_table); +#endif + register_sysctl_table(pty_root_table); /* Now create the /dev/ptmx special device */ tty_default_fops(&ptmx_fops); diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index ac41af8..47aa437 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -276,7 +276,7 @@ static struct tty_driver *get_tty_driver(dev_t device, int *index) if (device < base || device >= base + p->num) continue; *index = device - base; - return p; + return tty_driver_kref_get(p); } return NULL; } @@ -320,7 +320,7 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line) if (tty_line >= 0 && tty_line <= p->num && p->ops && p->ops->poll_init && !p->ops->poll_init(p, tty_line, str)) { - res = p; + res = tty_driver_kref_get(p); *line = tty_line; break; } @@ -1410,7 +1410,7 @@ int tty_init_dev(struct tty_driver *driver, int idx, *o_ltp_loc = o_ltp; o_tty->termios = *o_tp_loc; o_tty->termios_locked = *o_ltp_loc; - driver->other->refcount++; + tty_driver_kref_get(driver->other); if (driver->subtype == PTY_TYPE_MASTER) o_tty->count++; @@ -1438,7 +1438,7 @@ int tty_init_dev(struct tty_driver *driver, int idx, /* Compatibility until drivers always set this */ tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); - driver->refcount++; + tty_driver_kref_get(driver); tty->count++; /* @@ -1530,8 +1530,7 @@ static void release_one_tty(struct kref *kref) else tty_shutdown(tty); tty->magic = 0; - /* FIXME: locking on tty->driver->refcount */ - tty->driver->refcount--; + tty_driver_kref_put(driver); module_put(driver->owner); file_list_lock(); @@ -1854,7 +1853,7 @@ retry_open: mutex_unlock(&tty_mutex); return -ENXIO; } - driver = tty->driver; + driver = tty_driver_kref_get(tty->driver); index = tty->index; filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ /* noctty = 1; */ @@ -1865,14 +1864,14 @@ retry_open: #ifdef CONFIG_VT if (device == MKDEV(TTY_MAJOR, 0)) { extern struct tty_driver *console_driver; - driver = console_driver; + driver = tty_driver_kref_get(console_driver); index = fg_console; noctty = 1; goto got_driver; } #endif if (device == MKDEV(TTYAUX_MAJOR, 1)) { - driver = console_device(&index); + driver = tty_driver_kref_get(console_device(&index)); if (driver) { /* Don't let /dev/console block */ filp->f_flags |= O_NONBLOCK; @@ -1891,6 +1890,7 @@ retry_open: got_driver: retval = tty_init_dev(driver, index, &tty, 0); mutex_unlock(&tty_mutex); + tty_driver_kref_put(driver); if (retval) return retval; @@ -2866,7 +2866,6 @@ int tty_put_char(struct tty_struct *tty, unsigned char ch) return tty->ops->put_char(tty, ch); return tty->ops->write(tty, &ch, 1); } - EXPORT_SYMBOL_GPL(tty_put_char); struct class *tty_class; @@ -2909,6 +2908,7 @@ struct device *tty_register_device(struct tty_driver *driver, unsigned index, return device_create_drvdata(tty_class, device, dev, NULL, name); } +EXPORT_SYMBOL(tty_register_device); /** * tty_unregister_device - unregister a tty device @@ -2926,8 +2926,6 @@ void tty_unregister_device(struct tty_driver *driver, unsigned index) device_destroy(tty_class, MKDEV(driver->major, driver->minor_start) + index); } - -EXPORT_SYMBOL(tty_register_device); EXPORT_SYMBOL(tty_unregister_device); struct tty_driver *alloc_tty_driver(int lines) @@ -2936,27 +2934,70 @@ struct tty_driver *alloc_tty_driver(int lines) driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); if (driver) { + kref_init(&driver->kref); driver->magic = TTY_DRIVER_MAGIC; driver->num = lines; /* later we'll move allocation of tables here */ } return driver; } +EXPORT_SYMBOL(alloc_tty_driver); -void put_tty_driver(struct tty_driver *driver) +static void destruct_tty_driver(struct kref *kref) { + struct tty_driver *driver = container_of(kref, struct tty_driver, kref); + int i; + struct ktermios *tp; + void *p; + + if (driver->flags & TTY_DRIVER_INSTALLED) { + /* + * Free the termios and termios_locked structures because + * we don't want to get memory leaks when modular tty + * drivers are removed from the kernel. + */ + for (i = 0; i < driver->num; i++) { + tp = driver->termios[i]; + if (tp) { + driver->termios[i] = NULL; + kfree(tp); + } + tp = driver->termios_locked[i]; + if (tp) { + driver->termios_locked[i] = NULL; + kfree(tp); + } + if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) + tty_unregister_device(driver, i); + } + p = driver->ttys; + proc_tty_unregister_driver(driver); + driver->ttys = NULL; + driver->termios = driver->termios_locked = NULL; + kfree(p); + cdev_del(&driver->cdev); + } kfree(driver); } +void tty_driver_kref_put(struct tty_driver *driver) +{ + kref_put(&driver->kref, destruct_tty_driver); +} +EXPORT_SYMBOL(tty_driver_kref_put); + void tty_set_operations(struct tty_driver *driver, const struct tty_operations *op) { driver->ops = op; }; +EXPORT_SYMBOL(tty_set_operations); -EXPORT_SYMBOL(alloc_tty_driver); +void put_tty_driver(struct tty_driver *d) +{ + tty_driver_kref_put(d); +} EXPORT_SYMBOL(put_tty_driver); -EXPORT_SYMBOL(tty_set_operations); /* * Called by a tty driver to register itself. @@ -2968,9 +3009,6 @@ int tty_register_driver(struct tty_driver *driver) dev_t dev; void **p = NULL; - if (driver->flags & TTY_DRIVER_INSTALLED) - return 0; - if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) { p = kzalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL); if (!p) @@ -3024,6 +3062,7 @@ int tty_register_driver(struct tty_driver *driver) tty_register_device(driver, i, NULL); } proc_tty_register_driver(driver); + driver->flags |= TTY_DRIVER_INSTALLED; return 0; } @@ -3034,46 +3073,19 @@ EXPORT_SYMBOL(tty_register_driver); */ int tty_unregister_driver(struct tty_driver *driver) { - int i; - struct ktermios *tp; - void *p; - +#if 0 + /* FIXME */ if (driver->refcount) return -EBUSY; - +#endif unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), driver->num); mutex_lock(&tty_mutex); list_del(&driver->tty_drivers); mutex_unlock(&tty_mutex); - - /* - * Free the termios and termios_locked structures because - * we don't want to get memory leaks when modular tty - * drivers are removed from the kernel. - */ - for (i = 0; i < driver->num; i++) { - tp = driver->termios[i]; - if (tp) { - driver->termios[i] = NULL; - kfree(tp); - } - tp = driver->termios_locked[i]; - if (tp) { - driver->termios_locked[i] = NULL; - kfree(tp); - } - if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) - tty_unregister_device(driver, i); - } - p = driver->ttys; - proc_tty_unregister_driver(driver); - driver->ttys = NULL; - driver->termios = driver->termios_locked = NULL; - kfree(p); - cdev_del(&driver->cdev); return 0; } + EXPORT_SYMBOL(tty_unregister_driver); dev_t tty_devnum(struct tty_struct *tty) diff --git a/drivers/net/wan/Kconfig b/drivers/net/wan/Kconfig index 2ae2ec4..21efd99 100644 --- a/drivers/net/wan/Kconfig +++ b/drivers/net/wan/Kconfig @@ -205,7 +205,7 @@ config WANXL_BUILD_FIRMWARE config PC300 tristate "Cyclades-PC300 support (RS-232/V.35, X.21, T1/E1 boards)" - depends on HDLC && PCI + depends on HDLC && PCI && BROKEN ---help--- Driver for the Cyclades-PC300 synchronous communication boards. diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h index 2c5c35c..ba891dd 100644 --- a/include/linux/tty_driver.h +++ b/include/linux/tty_driver.h @@ -253,6 +253,7 @@ struct tty_operations { struct tty_driver { int magic; /* magic number for this structure */ + struct kref kref; /* Reference management */ struct cdev cdev; struct module *owner; const char *driver_name; @@ -266,7 +267,6 @@ struct tty_driver { short subtype; /* subtype of tty driver */ struct ktermios init_termios; /* Initial termios */ int flags; /* tty driver flags */ - int refcount; /* for loadable tty drivers */ struct proc_dir_entry *proc_entry; /* /proc fs entry */ struct tty_driver *other; /* only used for the PTY driver */ @@ -288,12 +288,19 @@ struct tty_driver { extern struct list_head tty_drivers; -struct tty_driver *alloc_tty_driver(int lines); -void put_tty_driver(struct tty_driver *driver); -void tty_set_operations(struct tty_driver *driver, +extern struct tty_driver *alloc_tty_driver(int lines); +extern void put_tty_driver(struct tty_driver *driver); +extern void tty_set_operations(struct tty_driver *driver, const struct tty_operations *op); extern struct tty_driver *tty_find_polling_driver(char *name, int *line); +extern void tty_driver_kref_put(struct tty_driver *driver); +extern inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d) +{ + kref_get(&d->kref); + return d; +} + /* tty driver magic number */ #define TTY_DRIVER_MAGIC 0x5402 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/