proc tty: add struct tty_operations::proc_fops

Used for gradual switch of TTY drivers from using ->read_proc which helps
with gradual switch from ->read_proc for the whole tree.

As side effect, fix possible race condition when ->data initialized after
PDE is hooked into proc tree.

->proc_fops takes precedence over ->read_proc.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index 08e088334dba..c9a69575ded6 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -264,6 +264,7 @@ struct tty_operations {
         int (*poll_get_char)(struct tty_driver *driver, int line);
         void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
 #endif
+        const struct file_operations *proc_fops;
 };
 
 struct tty_driver {