kernfs: fix barrier usage in __kernfs_new_node()

smp_mb__before_atomic() can not be applied to atomic_set().  Remove the
barrier and rely on RELEASE synchronization.

Fixes: ba16b2846a ("kernfs: add an API to get kernfs node from inode number")
Cc: stable@vger.kernel.org
Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Andrea Parri 2019-04-16 14:17:11 +02:00 committed by Greg Kroah-Hartman
parent 0d1a393d61
commit 998267900c

View File

@ -650,11 +650,10 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root,
kn->id.generation = gen;
/*
* set ino first. This barrier is paired with atomic_inc_not_zero in
* set ino first. This RELEASE is paired with atomic_inc_not_zero in
* kernfs_find_and_get_node_by_ino
*/
smp_mb__before_atomic();
atomic_set(&kn->count, 1);
atomic_set_release(&kn->count, 1);
atomic_set(&kn->active, KN_DEACTIVATED_BIAS);
RB_CLEAR_NODE(&kn->rb);