From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.179 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794301987; b=admKBD3vrn+QGwOLxl64uQBrvXT9XHBafsyJndTd2xS8mKeU5W4Y3h2hCmt//s3KNzJn qdvSpiQJxfHPvQPLw/QV/eVfeyOer1oGDioc4LPlPKR7+CiobdzbvKnokB9sPU9l575vH dp8nG3zH7VLHktnqUBumAjqeQwrAD7ewPz2NSoNVEINsGBblj4rNzZmqPENrxwYPRQusU hDgjtTwG2zZsRAGwfGwIXasNKrSuFUZDWK/KH1BPuSZN1yI25KwLjpVtTIX3GdmA88/ox UHrx5hxLxTW7UmJjHb6nsEuPENskmNRPA1GE7n1FbvdrBbE34ylnhS6+y4r8ynrwsTg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794301987; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Subject:Date:Message-ID: X-Mailer:MIME-Version:Content-Transfer-Encoding; bh=izg1/u7+/ux2L4ZiZrrTUgbq8wQG42pDQrKMiFlfrYY=; b=ef55vg2Vh081J8fc6YilFldtr2Ew82z0CcWB/dY/JF/lGhs1feCF++BSDkElwEVM521/ snYC/aCUWlKwUEvZy1vPWd1hbzK71firEKOUPR+kt7IJBDnsWyvr1fXoHJdo1xKyTwXi8 3/DPpBKK8fcGzkcvym7uyJN1Vpi1LkzkKQBvChBiwiFEplArVC5Jo2a51aeiOe33yUUCX vFlP4z+n9WxwF+PDjk2vTPoh23ssCU5YKy13ywfFRrwKYJLe2IUReFRfTOTe79LNrUZ80 SgVeuTW2LbNbLEDmprJ2yv1Na8gF9XzyYc4q3i5p0Q0E0CDO1SDfFhXAyQIws6rrhHA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=BciGz++M; arc=none smtp.remote-ip=95.215.58.179 Received: from mta1.migadu.com (out-179.mta1.migadu.com [95.215.58.179]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 42EEB606A31C for ; Tue, 10 Nov 2026 09:13:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 42EEB606A31C Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=BciGz++M X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=9i5PlLUyKyJmdin+eBEuKSO1iz4ih+sE3+AEMixQ/yI=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1794301984; v=1; x=1794906784; b=BciGz++M8/YRWdV9QUeaHsQIkB2E/2EEtThZVVFqunJxHxNuteLqmNMtMXkGlmWs8Im3CLPp etCg0q2n/zJfDshOGrATt/Wmvc0x6a+7zeyFjUzhJ67qQxy1zEShKXF9/vkIo+ijLyW5Z1J/oMk L75GhzrCCa1YriWtBu6x0+cc= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 85d5aaf2a0870739; Tue, 10 Nov 2026 09:13:04 +0000 X-Mizu-Trace-ID: 85d5aaf2a0870739 X-Migadu-Flow: FLOW_OUT From: Qingfang Deng To: Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Qingfang Deng , Simon Horman , Eric Woudstra , Asim Viladi Oglu Manizada , Felix Fietkau , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net-next] pppoe: use sk_node for session hash chains Date: Tue, 10 Nov 2026 17:12:52 +0800 Message-ID: <20261110091255.24158-1-qingfang.deng@linux.dev> X-Mailer: git-send-email 2.43.0 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit PPPoE uses a private next pointer to chain sockets in each hash bucket. Removing a socket requires walking the chain to find its predecessor. Use sock.sk_node and the standard hlist helpers to allow constant-time removal and eliminate pppox_sock.next. Cache the bucket index in sk_hash before publishing the socket and use it to advance /proc/net/pppoe iteration between buckets. Signed-off-by: Qingfang Deng --- drivers/net/ppp/pppoe.c | 101 +++++++++++++-------------------------- include/linux/if_pppox.h | 1 - 2 files changed, 34 insertions(+), 68 deletions(-) diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c index 67c28ac763ef..de6edc31790f 100644 --- a/drivers/net/ppp/pppoe.c +++ b/drivers/net/ppp/pppoe.c @@ -99,7 +99,7 @@ struct pppoe_net { * as well, moreover in case of SMP less locking * controversy here */ - struct pppox_sock __rcu *hash_table[PPPOE_HASH_SIZE]; + struct hlist_head hash_table[PPPOE_HASH_SIZE]; spinlock_t hash_lock; }; @@ -159,15 +159,14 @@ static struct pppox_sock *__get_item(struct pppoe_net *pn, __be16 sid, unsigned char *addr, int ifindex) { int hash = hash_item(sid, addr); - struct pppox_sock *ret; + struct sock *sk; + + sk_for_each_rcu(sk, &pn->hash_table[hash]) { + struct pppox_sock *ret = pppox_sk(sk); - ret = rcu_dereference(pn->hash_table[hash]); - while (ret) { if (cmp_addr(&ret->pppoe_pa, sid, addr) && ret->pppoe_ifindex == ifindex) return ret; - - ret = rcu_dereference(ret->next); } return NULL; @@ -176,47 +175,22 @@ static struct pppox_sock *__get_item(struct pppoe_net *pn, __be16 sid, static int __set_item(struct pppoe_net *pn, struct pppox_sock *po) { int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote); - struct pppox_sock *ret, *first; + struct sock *sk; + + sk_for_each(sk, &pn->hash_table[hash]) { + struct pppox_sock *ret = pppox_sk(sk); - first = rcu_dereference_protected(pn->hash_table[hash], lockdep_is_held(&pn->hash_lock)); - ret = first; - while (ret) { if (cmp_2_addr(&ret->pppoe_pa, &po->pppoe_pa) && ret->pppoe_ifindex == po->pppoe_ifindex) return -EALREADY; - - ret = rcu_dereference_protected(ret->next, lockdep_is_held(&pn->hash_lock)); } - RCU_INIT_POINTER(po->next, first); - rcu_assign_pointer(pn->hash_table[hash], po); + po->sk.sk_hash = hash; + hlist_add_head_rcu(&po->sk.sk_node, &pn->hash_table[hash]); return 0; } -static void __delete_item(struct pppoe_net *pn, const struct pppox_sock *po) -{ - int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote); - struct pppox_sock *ret, __rcu **src; - - ret = rcu_dereference_protected(pn->hash_table[hash], lockdep_is_held(&pn->hash_lock)); - src = &pn->hash_table[hash]; - - while (ret) { - if (ret == po) { - struct pppox_sock *next; - - next = rcu_dereference_protected(ret->next, - lockdep_is_held(&pn->hash_lock)); - rcu_assign_pointer(*src, next); - break; - } - - src = &ret->next; - ret = rcu_dereference_protected(ret->next, lockdep_is_held(&pn->hash_lock)); - } -} - /********************************************************************** * * Set/get/delete/rehash items @@ -234,10 +208,10 @@ static inline struct pppox_sock *get_item(struct pppoe_net *pn, __be16 sid, return po; } -static void delete_item(struct pppoe_net *pn, const struct pppox_sock *po) +static void delete_item(struct pppoe_net *pn, struct pppox_sock *po) { spin_lock(&pn->hash_lock); - __delete_item(pn, po); + __sk_del_node_init(&po->sk); spin_unlock(&pn->hash_lock); } @@ -256,20 +230,15 @@ static void pppoe_flush_dev(struct net_device *dev) pn = pppoe_pernet(dev_net(dev)); spin_lock(&pn->hash_lock); for (i = 0; i < PPPOE_HASH_SIZE; i++) { - struct pppox_sock *po = rcu_dereference_protected(pn->hash_table[i], - lockdep_is_held(&pn->hash_lock)); - struct sock *sk; - - while (po) { - while (po && po->pppoe_dev != dev) { - po = rcu_dereference_protected(po->next, - lockdep_is_held(&pn->hash_lock)); - } + struct sock *sk = sk_head(&pn->hash_table[i]); - if (!po) - break; + while (sk) { + struct pppox_sock *po = pppox_sk(sk); - sk = &po->sk; + if (po->pppoe_dev != dev) { + sk = sk_next(sk); + continue; + } /* We always grab the socket lock, followed by the * hash_lock, in that order. Since we should hold the @@ -301,8 +270,7 @@ static void pppoe_flush_dev(struct net_device *dev) BUG_ON(pppoe_pernet(dev_net(dev)) == NULL); spin_lock(&pn->hash_lock); - po = rcu_dereference_protected(pn->hash_table[i], - lockdep_is_held(&pn->hash_lock)); + sk = sk_head(&pn->hash_table[i]); } } spin_unlock(&pn->hash_lock); @@ -633,7 +601,6 @@ static int pppoe_connect(struct socket *sock, struct sockaddr_unsized *uservaddr po->pppoe_ifindex = 0; memset(&po->pppoe_pa, 0, sizeof(po->pppoe_pa)); memset(&po->chan, 0, sizeof(po->chan)); - po->next = NULL; po->num = 0; sk->sk_state = PPPOX_NONE; @@ -970,20 +937,17 @@ static int pppoe_seq_show(struct seq_file *seq, void *v) static inline struct pppox_sock *pppoe_get_idx(struct pppoe_net *pn, loff_t pos) { - struct pppox_sock *po; + struct sock *sk; int i; for (i = 0; i < PPPOE_HASH_SIZE; i++) { - po = rcu_dereference(pn->hash_table[i]); - while (po) { + sk_for_each_rcu(sk, &pn->hash_table[i]) { if (!pos--) - goto out; - po = rcu_dereference(po->next); + return pppox_sk(sk); } } -out: - return po; + return NULL; } static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos) @@ -999,7 +963,8 @@ static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos) static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos) { struct pppoe_net *pn = pppoe_pernet(seq_file_net(seq)); - struct pppox_sock *po, *next; + struct hlist_node *next; + struct pppox_sock *po; ++*pos; if (v == SEQ_START_TOKEN) { @@ -1007,17 +972,19 @@ static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos) goto out; } po = v; - next = rcu_dereference(po->next); + next = rcu_dereference(hlist_next_rcu(&po->sk.sk_node)); if (next) - po = next; + po = pppox_sk(sk_entry(next)); else { - int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote); + unsigned int hash = po->sk.sk_hash; po = NULL; while (++hash < PPPOE_HASH_SIZE) { - po = rcu_dereference(pn->hash_table[hash]); - if (po) + next = rcu_dereference(hlist_first_rcu(&pn->hash_table[hash])); + if (next) { + po = pppox_sk(sk_entry(next)); break; + } } } diff --git a/include/linux/if_pppox.h b/include/linux/if_pppox.h index 594d6dc3f4c9..aafdf72cfd2c 100644 --- a/include/linux/if_pppox.h +++ b/include/linux/if_pppox.h @@ -41,7 +41,6 @@ struct pppox_sock { /* struct sock must be the first member of pppox_sock */ struct sock sk; struct ppp_channel chan; - struct pppox_sock __rcu *next; /* for hash table */ union { struct pppoe_opt pppoe; struct pptp_opt pptp; -- 2.43.0