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tty: Remove more special casing and out of place code

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Carry on pushing code out of tty_io when it belongs to other drivers. I'm
not 100% happy with some of this and it will be worth revisiting some of the
exports later when the restructuring work is done.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alan Cox
2008-10-13 10:41:42 +01:00
committed by Linus Torvalds
parent feebed6515
commit d81ed10307
6 changed files with 195 additions and 156 deletions
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169
drivers/char/tty_io.c
View File

@@ -49,7 +49,7 @@
* implement CONFIG_VT and generalize console device interface.
* -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97
*
* Rewrote init_dev and release_dev to eliminate races.
* Rewrote tty_init_dev and tty_release_dev to eliminate races.
* -- Bill Hawes <whawes@star.net>, June 97
*
* Added devfs support.
@@ -136,11 +136,6 @@ LIST_HEAD(tty_drivers); /* linked list of tty drivers */
DEFINE_MUTEX(tty_mutex);
EXPORT_SYMBOL(tty_mutex);
#ifdef CONFIG_UNIX98_PTYS
extern struct tty_driver *ptm_driver; /* Unix98 pty masters; for /dev/ptmx */
static int ptmx_open(struct inode *, struct file *);
#endif
static void initialize_tty_struct(struct tty_struct *tty);
static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);
@@ -425,20 +420,6 @@ static const struct file_operations tty_fops = {
.fasync = tty_fasync,
};
#ifdef CONFIG_UNIX98_PTYS
static const struct file_operations ptmx_fops = {
.llseek = no_llseek,
.read = tty_read,
.write = tty_write,
.poll = tty_poll,
.unlocked_ioctl = tty_ioctl,
.compat_ioctl = tty_compat_ioctl,
.open = ptmx_open,
.release = tty_release,
.fasync = tty_fasync,
};
#endif
static const struct file_operations console_fops = {
.llseek = no_llseek,
.read = tty_read,
@@ -1224,7 +1205,7 @@ static void tty_line_name(struct tty_driver *driver, int index, char *p)
}
/**
* init_dev - initialise a tty device
* tty_init_dev - initialise a tty device
* @driver: tty driver we are opening a device on
* @idx: device index
* @ret_tty: returned tty structure
@@ -1248,7 +1229,7 @@ static void tty_line_name(struct tty_driver *driver, int index, char *p)
* relaxed for the (most common) case of reopening a tty.
*/
static int init_dev(struct tty_driver *driver, int idx,
int tty_init_dev(struct tty_driver *driver, int idx,
struct tty_struct **ret_tty, int first_ok)
{
struct tty_struct *tty, *o_tty;
@@ -1269,8 +1250,8 @@ static int init_dev(struct tty_driver *driver, int idx,
goto end_init;
}
/*
* It's safe from now on because init_dev() is called with
* tty_mutex held and release_dev() won't change tty->count
* It's safe from now on because tty_init_dev() is called with
* tty_mutex held and tty_release_dev() won't change tty->count
* or tty->flags without having to grab tty_mutex
*/
if (tty && driver->subtype == PTY_TYPE_MASTER)
@@ -1449,7 +1430,7 @@ fast_track:
/* FIXME */
if (!test_bit(TTY_LDISC, &tty->flags))
printk(KERN_ERR "init_dev but no ldisc\n");
printk(KERN_ERR "tty_init_dev but no ldisc\n");
success:
*ret_tty = tty;
@@ -1476,7 +1457,7 @@ fail_no_mem:
/* call the tty release_tty routine to clean out this slot */
release_mem_out:
if (printk_ratelimit())
printk(KERN_INFO "init_dev: ldisc open failed, "
printk(KERN_INFO "tty_init_dev: ldisc open failed, "
"clearing slot %d\n", idx);
release_tty(tty, idx);
goto end_init;
@@ -1587,7 +1568,7 @@ static void release_tty(struct tty_struct *tty, int idx)
* WSH 09/09/97: rewritten to avoid some nasty race conditions that could
* lead to double frees or releasing memory still in use.
*/
static void release_dev(struct file *filp)
void tty_release_dev(struct file *filp)
{
struct tty_struct *tty, *o_tty;
int pty_master, tty_closing, o_tty_closing, do_sleep;
@@ -1597,10 +1578,10 @@ static void release_dev(struct file *filp)
tty = (struct tty_struct *)filp->private_data;
if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode,
"release_dev"))
"tty_release_dev"))
return;
check_tty_count(tty, "release_dev");
check_tty_count(tty, "tty_release_dev");
tty_fasync(-1, filp, 0);
@@ -1612,24 +1593,24 @@ static void release_dev(struct file *filp)
#ifdef TTY_PARANOIA_CHECK
if (idx < 0 || idx >= tty->driver->num) {
printk(KERN_DEBUG "release_dev: bad idx when trying to "
printk(KERN_DEBUG "tty_release_dev: bad idx when trying to "
"free (%s)\n", tty->name);
return;
}
if (!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
if (tty != tty->driver->ttys[idx]) {
printk(KERN_DEBUG "release_dev: driver.table[%d] not tty "
printk(KERN_DEBUG "tty_release_dev: driver.table[%d] not tty "
"for (%s)\n", idx, tty->name);
return;
}
if (tty->termios != tty->driver->termios[idx]) {
printk(KERN_DEBUG "release_dev: driver.termios[%d] not termios "
printk(KERN_DEBUG "tty_release_dev: driver.termios[%d] not termios "
"for (%s)\n",
idx, tty->name);
return;
}
if (tty->termios_locked != tty->driver->termios_locked[idx]) {
printk(KERN_DEBUG "release_dev: driver.termios_locked[%d] not "
printk(KERN_DEBUG "tty_release_dev: driver.termios_locked[%d] not "
"termios_locked for (%s)\n",
idx, tty->name);
return;
@@ -1638,7 +1619,7 @@ static void release_dev(struct file *filp)
#endif
#ifdef TTY_DEBUG_HANGUP
printk(KERN_DEBUG "release_dev of %s (tty count=%d)...",
printk(KERN_DEBUG "tty_release_dev of %s (tty count=%d)...",
tty_name(tty, buf), tty->count);
#endif
@@ -1646,26 +1627,26 @@ static void release_dev(struct file *filp)
if (tty->driver->other &&
!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
if (o_tty != tty->driver->other->ttys[idx]) {
printk(KERN_DEBUG "release_dev: other->table[%d] "
printk(KERN_DEBUG "tty_release_dev: other->table[%d] "
"not o_tty for (%s)\n",
idx, tty->name);
return;
}
if (o_tty->termios != tty->driver->other->termios[idx]) {
printk(KERN_DEBUG "release_dev: other->termios[%d] "
printk(KERN_DEBUG "tty_release_dev: other->termios[%d] "
"not o_termios for (%s)\n",
idx, tty->name);
return;
}
if (o_tty->termios_locked !=
tty->driver->other->termios_locked[idx]) {
printk(KERN_DEBUG "release_dev: other->termios_locked["
printk(KERN_DEBUG "tty_release_dev: other->termios_locked["
"%d] not o_termios_locked for (%s)\n",
idx, tty->name);
return;
}
if (o_tty->link != tty) {
printk(KERN_DEBUG "release_dev: bad pty pointers\n");
printk(KERN_DEBUG "tty_release_dev: bad pty pointers\n");
return;
}
}
@@ -1723,7 +1704,7 @@ static void release_dev(struct file *filp)
if (!do_sleep)
break;
printk(KERN_WARNING "release_dev: %s: read/write wait queue "
printk(KERN_WARNING "tty_release_dev: %s: read/write wait queue "
"active!\n", tty_name(tty, buf));
mutex_unlock(&tty_mutex);
schedule();
@@ -1736,14 +1717,14 @@ static void release_dev(struct file *filp)
*/
if (pty_master) {
if (--o_tty->count < 0) {
printk(KERN_WARNING "release_dev: bad pty slave count "
printk(KERN_WARNING "tty_release_dev: bad pty slave count "
"(%d) for %s\n",
o_tty->count, tty_name(o_tty, buf));
o_tty->count = 0;
}
}
if (--tty->count < 0) {
printk(KERN_WARNING "release_dev: bad tty->count (%d) for %s\n",
printk(KERN_WARNING "tty_release_dev: bad tty->count (%d) for %s\n",
tty->count, tty_name(tty, buf));
tty->count = 0;
}
@@ -1825,7 +1806,7 @@ static void release_dev(struct file *filp)
* The termios state of a pty is reset on first open so that
* settings don't persist across reuse.
*
* Locking: tty_mutex protects tty, get_tty_driver and init_dev work.
* Locking: tty_mutex protects tty, get_tty_driver and tty_init_dev work.
* tty->count should protect the rest.
* ->siglock protects ->signal/->sighand
*/
@@ -1889,7 +1870,7 @@ retry_open:
return -ENODEV;
}
got_driver:
retval = init_dev(driver, index, &tty, 0);
retval = tty_init_dev(driver, index, &tty, 0);
mutex_unlock(&tty_mutex);
if (retval)
return retval;
@@ -1920,7 +1901,7 @@ got_driver:
printk(KERN_DEBUG "error %d in opening %s...", retval,
tty->name);
#endif
release_dev(filp);
tty_release_dev(filp);
if (retval != -ERESTARTSYS)
return retval;
if (signal_pending(current))
@@ -1959,69 +1940,6 @@ static int tty_open(struct inode *inode, struct file *filp)
#ifdef CONFIG_UNIX98_PTYS
/**
* ptmx_open - open a unix 98 pty master
* @inode: inode of device file
* @filp: file pointer to tty
*
* Allocate a unix98 pty master device from the ptmx driver.
*
* Locking: tty_mutex protects theinit_dev work. tty->count should
* protect the rest.
* allocated_ptys_lock handles the list of free pty numbers
*/
static int __ptmx_open(struct inode *inode, struct file *filp)
{
struct tty_struct *tty;
int retval;
int index;
nonseekable_open(inode, filp);
/* find a device that is not in use. */
index = devpts_new_index();
if (index < 0)
return index;
mutex_lock(&tty_mutex);
retval = init_dev(ptm_driver, index, &tty, 1);
mutex_unlock(&tty_mutex);
if (retval)
goto out;
set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
filp->private_data = tty;
file_move(filp, &tty->tty_files);
retval = devpts_pty_new(tty->link);
if (retval)
goto out1;
check_tty_count(tty, "ptmx_open");
retval = ptm_driver->ops->open(tty, filp);
if (!retval)
return 0;
out1:
release_dev(filp);
return retval;
out:
devpts_kill_index(index);
return retval;
}
static int ptmx_open(struct inode *inode, struct file *filp)
{
int ret;
lock_kernel();
ret = __ptmx_open(inode, filp);
unlock_kernel();
return ret;
}
#endif
/**
* tty_release - vfs callback for close
@@ -2032,13 +1950,13 @@ static int ptmx_open(struct inode *inode, struct file *filp)
* this tty. There may however be several such references.
*
* Locking:
* Takes bkl. See release_dev
* Takes bkl. See tty_release_dev
*/
static int tty_release(struct inode *inode, struct file *filp)
{
lock_kernel();
release_dev(filp);
tty_release_dev(filp);
unlock_kernel();
return 0;
}
@@ -2932,7 +2850,7 @@ int tty_put_char(struct tty_struct *tty, unsigned char ch)
EXPORT_SYMBOL_GPL(tty_put_char);
static struct class *tty_class;
struct class *tty_class;
/**
* tty_register_device - register a tty device
@@ -3197,6 +3115,11 @@ struct tty_struct *get_current_tty(void)
}
EXPORT_SYMBOL_GPL(get_current_tty);
void tty_default_fops(struct file_operations *fops)
{
*fops = tty_fops;
}
/*
* Initialize the console device. This is called *early*, so
* we can't necessarily depend on lots of kernel help here.
@@ -3234,12 +3157,6 @@ postcore_initcall(tty_class_init);
/* 3/2004 jmc: why do these devices exist? */
static struct cdev tty_cdev, console_cdev;
#ifdef CONFIG_UNIX98_PTYS
static struct cdev ptmx_cdev;
#endif
#ifdef CONFIG_VT
static struct cdev vc0_cdev;
#endif
/*
* Ok, now we can initialize the rest of the tty devices and can count
@@ -3251,32 +3168,18 @@ static int __init tty_init(void)
if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
panic("Couldn't register /dev/tty driver\n");
device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL,
device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL,
"tty");
cdev_init(&console_cdev, &console_fops);
if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
panic("Couldn't register /dev/console driver\n");
device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL,
device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL,
"console");
#ifdef CONFIG_UNIX98_PTYS
cdev_init(&ptmx_cdev, &ptmx_fops);
if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
panic("Couldn't register /dev/ptmx driver\n");
device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
#endif
#ifdef CONFIG_VT
cdev_init(&vc0_cdev, &console_fops);
if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
panic("Couldn't register /dev/tty0 driver\n");
device_create_drvdata(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
vty_init();
vty_init(&console_fops);
#endif
return 0;
}