tty: move the non-file related parts of tty_release to new tty_release_struct

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 <robh@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-By: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 734a635e73632910d3d418a1eb980b3430a0b8b5..4790c0fb5a45eeca2815e888b873369cbe59ef77 100644 (file)
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1744,6 +1744,37 @@ static int tty_release_checks(struct tty_struct *tty, int idx)
        return 0;
 }
 
+/**
+ *     tty_release_struct      -       release a tty struct
+ *     @tty: tty device
+ *     @idx: index of the tty
+ *
+ *     Performs the final steps to release and free a tty device. It is
+ *     roughly the reverse of tty_init_dev.
+ */
+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 +1929,8 @@ 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 40144f38251631dea097f0e7e03cba5928e31254..86c7853282b7efafc32ab8046e1834f3e76c5f41 100644 (file)
--- 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,