From: Nikos Tsironis <ntsironis@arrikto.com>
Date: Sun, 17 Mar 2019 12:22:53 +0000 (+0200)
Subject: list: Don't use WRITE_ONCE() in hlist_add_behind()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=ae325dcd1905925557dfdd03ae4b97e7ac6cd6a6;p=linux.git

list: Don't use WRITE_ONCE() in hlist_add_behind()

Commit 1c97be677f72b3 ("list: Use WRITE_ONCE() when adding to lists and
hlists") introduced the use of WRITE_ONCE() to atomically write the list
head's ->next pointer.

hlist_add_behind() doesn't touch the hlist head's ->first pointer so
there is no reason to use WRITE_ONCE() in this case.

Co-developed-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---

diff --git a/include/linux/list.h b/include/linux/list.h
index 58aa3adf94e63..e137b98cd31a2 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -754,7 +754,7 @@ static inline void hlist_add_behind(struct hlist_node *n,
 				    struct hlist_node *prev)
 {
 	n->next = prev->next;
-	WRITE_ONCE(prev->next, n);
+	prev->next = n;
 	n->pprev = &prev->next;
 
 	if (n->next)