From 527b3e4773628b30d03323a2cb5fb0d84441990f Mon Sep 17 00:00:00 2001 From: Sukadev Bhattiprolu Date: Mon, 13 Oct 2008 10:43:08 +0100 Subject: [PATCH] Simplify devpts_get_tty() As pointed out by H. Peter Anvin, since the inode for the pty is known, we don't need to look it up. Signed-off-by: Sukadev Bhattiprolu Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- fs/devpts/inode.c | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-) diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c index 638db9b769a..b292ed7ff1c 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); @@ -247,19 +248,11 @@ int devpts_pty_new(struct inode *ptmx_inode, struct tty_struct *tty) struct tty_struct *devpts_get_tty(struct inode *pts_inode, int number) { - struct dentry *dentry = get_node(number); - struct tty_struct *tty; + BUG_ON(pts_inode->i_rdev == MKDEV(TTYAUX_MAJOR, PTMX_MINOR)); - tty = NULL; - if (!IS_ERR(dentry)) { - if (dentry->d_inode) - tty = dentry->d_inode->i_private; - dput(dentry); - } - - 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(struct tty_struct *tty)