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authorSukadev Bhattiprolu <sukadev@us.ibm.com>2008-10-13 13:43:08 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-13 20:51:43 +0400
commit527b3e4773628b30d03323a2cb5fb0d84441990f (patch)
treed7dfcc1b716881162d93bf24ade602a77ca171ac /fs/devpts/inode.c
parent15f1a6338ddd4e69fff965d4b3a0e1bfb7a13d9c (diff)
downloadlinux-527b3e4773628b30d03323a2cb5fb0d84441990f.tar.xz
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 <sukadev@us.ibm.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/devpts/inode.c')
-rw-r--r--fs/devpts/inode.c17
1 files changed, 5 insertions, 12 deletions
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index 638db9b769ac..b292ed7ff1ca 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;
-
- 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);
+ BUG_ON(pts_inode->i_rdev == MKDEV(TTYAUX_MAJOR, PTMX_MINOR));
- 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)