For in-kernel tty users, we need to be able to create and destroy 'struct tty' that are not associated with a file. The creation side is fine, but tty_release() needs to be split into the file handle portion and the struct tty portion. Introduce a new function, tty_release_struct, to handle just the destroying of a struct tty.
Signed-off-by: Rob Herring <[email protected]> --- drivers/tty/tty_io.c | 42 ++++++++++++++++++++++++------------------ include/linux/tty.h | 1 + 2 files changed, 25 insertions(+), 18 deletions(-) diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 734a635e7363..5ebc090ec47f 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1744,6 +1744,29 @@ static int tty_release_checks(struct tty_struct *tty, int idx) return 0; } +void tty_release_struct(struct tty_struct *tty, int idx) +{ + /* + * Ask the line discipline code to release its structures + */ + tty_ldisc_release(tty); + + /* Wait for pending work before tty destruction commmences */ + tty_flush_works(tty); + + tty_debug_hangup(tty, "freeing structure\n"); + /* + * The release_tty function takes care of the details of clearing + * the slots and preserving the termios structure. The tty_unlock_pair + * should be safe as we keep a kref while the tty is locked (so the + * unlock never unlocks a freed tty). + */ + mutex_lock(&tty_mutex); + release_tty(tty, idx); + mutex_unlock(&tty_mutex); +} +EXPORT_SYMBOL_GPL(tty_release_struct); + /** * tty_release - vfs callback for close * @inode: inode of tty @@ -1898,25 +1921,8 @@ int tty_release(struct inode *inode, struct file *filp) return 0; tty_debug_hangup(tty, "final close\n"); - /* - * Ask the line discipline code to release its structures - */ - tty_ldisc_release(tty); - - /* Wait for pending work before tty destruction commmences */ - tty_flush_works(tty); - - tty_debug_hangup(tty, "freeing structure\n"); - /* - * The release_tty function takes care of the details of clearing - * the slots and preserving the termios structure. The tty_unlock_pair - * should be safe as we keep a kref while the tty is locked (so the - * unlock never unlocks a freed tty). - */ - mutex_lock(&tty_mutex); - release_tty(tty, idx); - mutex_unlock(&tty_mutex); + tty_release_struct(tty, idx); return 0; } diff --git a/include/linux/tty.h b/include/linux/tty.h index 40144f382516..86c7853282b7 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -528,6 +528,7 @@ extern int tty_alloc_file(struct file *file); extern void tty_add_file(struct tty_struct *tty, struct file *file); extern void tty_free_file(struct file *file); extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx); +extern void tty_release_struct(struct tty_struct *tty, int idx); extern int tty_release(struct inode *inode, struct file *filp); extern void tty_init_termios(struct tty_struct *tty); extern int tty_standard_install(struct tty_driver *driver, -- 2.10.1
