Patch "inetpeer: update inetpeer timestamp in inet_getpeer()" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    inetpeer: update inetpeer timestamp in inet_getpeer()

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     inetpeer-update-inetpeer-timestamp-in-inet_getpeer.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 79e00a4f5f2204584d994129b3f75d981ea2b2ae
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date:   Sun Dec 15 17:56:28 2024 +0000

    inetpeer: update inetpeer timestamp in inet_getpeer()
    
    [ Upstream commit 50b362f21d6c10b0f7939c1482c6a1b43da82f1a ]
    
    inet_putpeer() will be removed in the following patch,
    because we will no longer use refcounts.
    
    Update inetpeer timestamp (p->dtime) at lookup time.
    
    Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
    Link: https://patch.msgid.link/20241215175629.1248773-4-edumazet@xxxxxxxxxx
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Stable-dep-of: a853c609504e ("inetpeer: do not get a refcount in inet_getpeer()")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c
index 5670571ee5fbe..596e2c3a8551f 100644
--- a/net/ipv4/inetpeer.c
+++ b/net/ipv4/inetpeer.c
@@ -98,6 +98,7 @@ static struct inet_peer *lookup(const struct inetpeer_addr *daddr,
 {
 	struct rb_node **pp, *parent, *next;
 	struct inet_peer *p;
+	u32 now;
 
 	pp = &base->rb_root.rb_node;
 	parent = NULL;
@@ -113,6 +114,9 @@ static struct inet_peer *lookup(const struct inetpeer_addr *daddr,
 		if (cmp == 0) {
 			if (!refcount_inc_not_zero(&p->refcnt))
 				break;
+			now = jiffies;
+			if (READ_ONCE(p->dtime) != now)
+				WRITE_ONCE(p->dtime, now);
 			return p;
 		}
 		if (gc_stack) {
@@ -158,9 +162,6 @@ static void inet_peer_gc(struct inet_peer_base *base,
 	for (i = 0; i < gc_cnt; i++) {
 		p = gc_stack[i];
 
-		/* The READ_ONCE() pairs with the WRITE_ONCE()
-		 * in inet_putpeer()
-		 */
 		delta = (__u32)jiffies - READ_ONCE(p->dtime);
 
 		if (delta < ttl || !refcount_dec_if_one(&p->refcnt))
@@ -232,11 +233,6 @@ EXPORT_SYMBOL_GPL(inet_getpeer);
 
 void inet_putpeer(struct inet_peer *p)
 {
-	/* The WRITE_ONCE() pairs with itself (we run lockless)
-	 * and the READ_ONCE() in inet_peer_gc()
-	 */
-	WRITE_ONCE(p->dtime, (__u32)jiffies);
-
 	if (refcount_dec_and_test(&p->refcnt))
 		call_rcu(&p->rcu, inetpeer_free_rcu);
 }