From: Jonathan Corbet <corbet@lwn.net>
Date: Sun, 18 May 2008 21:39:11 +0000 (-0600)
Subject: Add a comment in chrdev_open()
X-Git-Tag: v2.6.27-rc1~1103^2~86
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a30427d92d0bc152b833088e4a305bbeb1a0c162;p=linux-2.6

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 <corbet@lwn.net>
---

diff --git a/fs/char_dev.c b/fs/char_dev.c
index 68e510b884..a54d69369b 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;