From a30427d92d0bc152b833088e4a305bbeb1a0c162 Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Sun, 18 May 2008 15:39:11 -0600 Subject: [PATCH] Add a comment in chrdev_open() I stared at this code for a while and almost deleted it before understanding crept into my slow brain. Hopefully this makes life easier for the next person to happen on it. Signed-off-by: Jonathan Corbet --- fs/char_dev.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/char_dev.c b/fs/char_dev.c index 68e510b88457..a54d69369b2f 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -373,6 +373,8 @@ static int chrdev_open(struct inode *inode, struct file *filp) return -ENXIO; new = container_of(kobj, struct cdev, kobj); spin_lock(&cdev_lock); + /* Check i_cdev again in case somebody beat us to it while + we dropped the lock. */ p = inode->i_cdev; if (!p) { inode->i_cdev = p = new;