From a30427d92d0bc152b833088e4a305bbeb1a0c162 Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Sun, 18 May 2008 15:39:11 -0600 Subject: 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(+) (limited to 'fs/char_dev.c') diff --git a/fs/char_dev.c b/fs/char_dev.c index 68e510b8845..a54d69369b2 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; -- cgit v1.2.3 From 9514dff918b947ae43b66517dc90d0e05548bd6a Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Sun, 18 May 2008 15:40:00 -0600 Subject: Remove the lock_kernel() call from chrdev_open() All in-kernel char device open() functions now either have their own lock_kernel() calls or clearly do not need one. Signed-off-by: Jonathan Corbet --- fs/char_dev.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'fs/char_dev.c') diff --git a/fs/char_dev.c b/fs/char_dev.c index a54d69369b2..3cb7cda3d78 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -394,11 +394,8 @@ static int chrdev_open(struct inode *inode, struct file *filp) cdev_put(p); return -ENXIO; } - if (filp->f_op->open) { - lock_kernel(); + if (filp->f_op->open) ret = filp->f_op->open(inode,filp); - unlock_kernel(); - } if (ret) cdev_put(p); return ret; -- cgit v1.2.3