1 files changed, 31 insertions, 37 deletions

diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index 488eb424f66..4a714f6c1be 100644
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -27,6 +27,7 @@
 #define DEVPTS_SUPER_MAGIC 0x1cd1
 
 #define DEVPTS_DEFAULT_MODE 0600
+#define PTMX_MINOR	2
 
 extern int pty_limit;			/* Config limit on Unix98 ptys */
 static DEFINE_IDA(allocated_ptys);
@@ -48,7 +49,7 @@ enum {
 	Opt_err
 };
 
-static match_table_t tokens = {
+static const match_table_t tokens = {
 	{Opt_uid, "uid=%u"},
 	{Opt_gid, "gid=%u"},
 	{Opt_mode, "mode=%o"},
@@ -169,15 +170,7 @@ static struct file_system_type devpts_fs_type = {
  * to the System V naming convention
  */
 
-static struct dentry *get_node(int num)
-{
-	char s[12];
-	struct dentry *root = devpts_root;
-	mutex_lock(&root->d_inode->i_mutex);
-	return lookup_one_len(s, root, sprintf(s, "%d", num));
-}
-
-int devpts_new_index(void)
+int devpts_new_index(struct inode *ptmx_inode)
 {
 	int index;
 	int ida_ret;
@@ -205,20 +198,21 @@ retry:
 	return index;
 }
 
-void devpts_kill_index(int idx)
+void devpts_kill_index(struct inode *ptmx_inode, int idx)
 {
 	mutex_lock(&allocated_ptys_lock);
 	ida_remove(&allocated_ptys, idx);
 	mutex_unlock(&allocated_ptys_lock);
 }
 
-int devpts_pty_new(struct tty_struct *tty)
+int devpts_pty_new(struct inode *ptmx_inode, struct tty_struct *tty)
 {
 	int number = tty->index; /* tty layer puts index from devpts_new_index() in here */
 	struct tty_driver *driver = tty->driver;
 	dev_t device = MKDEV(driver->major, driver->minor_start+number);
 	struct dentry *dentry;
 	struct inode *inode = new_inode(devpts_mnt->mnt_sb);
+	char s[12];
 
 	/* We're supposed to be given the slave end of a pty */
 	BUG_ON(driver->type != TTY_DRIVER_TYPE_PTY);
@@ -233,10 +227,15 @@ int devpts_pty_new(struct tty_struct *tty)
 	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
 	init_special_inode(inode, S_IFCHR|config.mode, device);
 	inode->i_private = tty;
+	tty->driver_data = inode;
 
-	dentry = get_node(number);
-	if (!IS_ERR(dentry) && !dentry->d_inode) {
-		d_instantiate(dentry, inode);
+	sprintf(s, "%d", number);
+
+	mutex_lock(&devpts_root->d_inode->i_mutex);
+
+	dentry = d_alloc_name(devpts_root, s);
+	if (!IS_ERR(dentry)) {
+		d_add(dentry, inode);
 		fsnotify_create(devpts_root->d_inode, dentry);
 	}
 
@@ -245,36 +244,31 @@ int devpts_pty_new(struct tty_struct *tty)
 	return 0;
 }
 
-struct tty_struct *devpts_get_tty(int number)
+struct tty_struct *devpts_get_tty(struct inode *pts_inode, int number)
 {
-	struct dentry *dentry = get_node(number);
-	struct tty_struct *tty;
-
-	tty = NULL;
-	if (!IS_ERR(dentry)) {
-		if (dentry->d_inode)
-			tty = dentry->d_inode->i_private;
-		dput(dentry);
-	}
+	BUG_ON(pts_inode->i_rdev == MKDEV(TTYAUX_MAJOR, PTMX_MINOR));
 
-	mutex_unlock(&devpts_root->d_inode->i_mutex);
-
-	return tty;
+	if (pts_inode->i_sb->s_magic == DEVPTS_SUPER_MAGIC)
+		return (struct tty_struct *)pts_inode->i_private;
+	return NULL;
 }
 
-void devpts_pty_kill(int number)
+void devpts_pty_kill(struct tty_struct *tty)
 {
-	struct dentry *dentry = get_node(number);
+	struct inode *inode = tty->driver_data;
+	struct dentry *dentry;
 
-	if (!IS_ERR(dentry)) {
-		struct inode *inode = dentry->d_inode;
-		if (inode) {
-			inode->i_nlink--;
-			d_delete(dentry);
-			dput(dentry);
-		}
+	BUG_ON(inode->i_rdev == MKDEV(TTYAUX_MAJOR, PTMX_MINOR));
+
+	mutex_lock(&devpts_root->d_inode->i_mutex);
+
+	dentry = d_find_alias(inode);
+	if (dentry && !IS_ERR(dentry)) {
+		inode->i_nlink--;
+		d_delete(dentry);
 		dput(dentry);
 	}
+
 	mutex_unlock(&devpts_root->d_inode->i_mutex);
 }