[PATCH] sysfs: move assignment to be under lock in sysfs_remove_dir()

[Greg KH <gregkh@linuxfoundation.org>]

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Linus noticed that the assignment of sd isn't protected by the lock in
sysfs_remove_dir(), so move the assignment of the variable under the
lock to be safe.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

Tejun, any objection to this patch?  You consolidated the locks back in
2007 on this function, and nothing has changed there since then, so odds
are it's not a problem, but nice to be safe, right?

 fs/sysfs/dir.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index eab59de4..2609f934 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -856,9 +856,10 @@ void sysfs_remove(struct sysfs_dirent *sd)
  */
 void sysfs_remove_dir(struct kobject *kobj)
 {
-	struct sysfs_dirent *sd = kobj->sd;
+	struct sysfs_dirent *sd;
 
 	spin_lock(&sysfs_assoc_lock);
+	sd = kobj->sd;
 	kobj->sd = NULL;
 	spin_unlock(&sysfs_assoc_lock);