From mboxrd@z Thu Jan 1 00:00:00 1970 From: sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org Subject: [PATCH 5/11][v3]: Simplify devpts_pty_kill Date: Wed, 3 Sep 2008 22:32:38 -0700 Message-ID: <20080904053238.GF3680@us.ibm.com> References: <20080904052718.GA3680@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20080904052718.GA3680-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org, alan-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org Cc: kyle-hoO6YkzgTuCM0SS3m2neIg@public.gmane.org, ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org, bastian-yyjItF7Rl6lg9hUCZPvPmw@public.gmane.org, containers-qjLDD68F18O7TbgM5vRIOg@public.gmane.org, sukadev-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org, xemul-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org List-Id: containers.vger.kernel.org From: Sukadev Bhattiprolu Subject: [PATCH 5/11]: Simplify devpts_pty_kill When creating a new pty, save the pty's inode in the tty->driver_data. Use this inode in pty_kill() to identify the devpts instance. Since we now have the inode for the pty, we can skip get_node() lookup and remove the unused get_node(). TODO: - check if the mutex_lock is needed in pty_kill(). Signed-off-by: Sukadev Bhattiprolu --- fs/devpts/inode.c | 29 ++++++++++++----------------- 1 file changed, 12 insertions(+), 17 deletions(-) Index: linux-2.6.27-rc3-tty/fs/devpts/inode.c =================================================================== --- linux-2.6.27-rc3-tty.orig/fs/devpts/inode.c 2008-08-28 18:46:55.000000000 -0700 +++ linux-2.6.27-rc3-tty/fs/devpts/inode.c 2008-08-28 23:27:20.000000000 -0700 @@ -170,14 +170,6 @@ static struct file_system_type devpts_fs * 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(struct inode *ptmx_inode) { int index; @@ -235,6 +227,7 @@ int devpts_pty_new(struct inode *ptmx_in 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; sprintf(s, "%d", number); @@ -262,18 +255,20 @@ struct tty_struct *devpts_get_tty(struct void devpts_pty_kill(struct tty_struct *tty) { - int number = tty->index; - 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); }