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Diffstat (limited to 'net/ipv4/tcp_metrics.c')
-rw-r--r--net/ipv4/tcp_metrics.c85
1 files changed, 51 insertions, 34 deletions
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index 4960e2b6b..60619b1f4 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -40,7 +40,7 @@ struct tcp_fastopen_metrics {
struct tcp_metrics_block {
struct tcp_metrics_block __rcu *tcpm_next;
- possible_net_t tcpm_net;
+ struct net *tcpm_net;
struct inetpeer_addr tcpm_saddr;
struct inetpeer_addr tcpm_daddr;
unsigned long tcpm_stamp;
@@ -51,34 +51,38 @@ struct tcp_metrics_block {
struct rcu_head rcu_head;
};
-static inline struct net *tm_net(struct tcp_metrics_block *tm)
+static inline struct net *tm_net(const struct tcp_metrics_block *tm)
{
- return read_pnet(&tm->tcpm_net);
+ /* Paired with the WRITE_ONCE() in tcpm_new() */
+ return READ_ONCE(tm->tcpm_net);
}
static bool tcp_metric_locked(struct tcp_metrics_block *tm,
enum tcp_metric_index idx)
{
- return tm->tcpm_lock & (1 << idx);
+ /* Paired with WRITE_ONCE() in tcpm_suck_dst() */
+ return READ_ONCE(tm->tcpm_lock) & (1 << idx);
}
-static u32 tcp_metric_get(struct tcp_metrics_block *tm,
+static u32 tcp_metric_get(const struct tcp_metrics_block *tm,
enum tcp_metric_index idx)
{
- return tm->tcpm_vals[idx];
+ /* Paired with WRITE_ONCE() in tcp_metric_set() */
+ return READ_ONCE(tm->tcpm_vals[idx]);
}
static void tcp_metric_set(struct tcp_metrics_block *tm,
enum tcp_metric_index idx,
u32 val)
{
- tm->tcpm_vals[idx] = val;
+ /* Paired with READ_ONCE() in tcp_metric_get() */
+ WRITE_ONCE(tm->tcpm_vals[idx], val);
}
static bool addr_same(const struct inetpeer_addr *a,
const struct inetpeer_addr *b)
{
- return inetpeer_addr_cmp(a, b) == 0;
+ return (a->family == b->family) && !inetpeer_addr_cmp(a, b);
}
struct tcpm_hash_bucket {
@@ -89,6 +93,7 @@ static struct tcpm_hash_bucket *tcp_metrics_hash __read_mostly;
static unsigned int tcp_metrics_hash_log __read_mostly;
static DEFINE_SPINLOCK(tcp_metrics_lock);
+static DEFINE_SEQLOCK(fastopen_seqlock);
static void tcpm_suck_dst(struct tcp_metrics_block *tm,
const struct dst_entry *dst,
@@ -97,7 +102,7 @@ static void tcpm_suck_dst(struct tcp_metrics_block *tm,
u32 msval;
u32 val;
- tm->tcpm_stamp = jiffies;
+ WRITE_ONCE(tm->tcpm_stamp, jiffies);
val = 0;
if (dst_metric_locked(dst, RTAX_RTT))
@@ -110,30 +115,42 @@ static void tcpm_suck_dst(struct tcp_metrics_block *tm,
val |= 1 << TCP_METRIC_CWND;
if (dst_metric_locked(dst, RTAX_REORDERING))
val |= 1 << TCP_METRIC_REORDERING;
- tm->tcpm_lock = val;
+ /* Paired with READ_ONCE() in tcp_metric_locked() */
+ WRITE_ONCE(tm->tcpm_lock, val);
msval = dst_metric_raw(dst, RTAX_RTT);
- tm->tcpm_vals[TCP_METRIC_RTT] = msval * USEC_PER_MSEC;
+ tcp_metric_set(tm, TCP_METRIC_RTT, msval * USEC_PER_MSEC);
msval = dst_metric_raw(dst, RTAX_RTTVAR);
- tm->tcpm_vals[TCP_METRIC_RTTVAR] = msval * USEC_PER_MSEC;
- tm->tcpm_vals[TCP_METRIC_SSTHRESH] = dst_metric_raw(dst, RTAX_SSTHRESH);
- tm->tcpm_vals[TCP_METRIC_CWND] = dst_metric_raw(dst, RTAX_CWND);
- tm->tcpm_vals[TCP_METRIC_REORDERING] = dst_metric_raw(dst, RTAX_REORDERING);
+ tcp_metric_set(tm, TCP_METRIC_RTTVAR, msval * USEC_PER_MSEC);
+ tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
+ dst_metric_raw(dst, RTAX_SSTHRESH));
+ tcp_metric_set(tm, TCP_METRIC_CWND,
+ dst_metric_raw(dst, RTAX_CWND));
+ tcp_metric_set(tm, TCP_METRIC_REORDERING,
+ dst_metric_raw(dst, RTAX_REORDERING));
if (fastopen_clear) {
+ write_seqlock(&fastopen_seqlock);
tm->tcpm_fastopen.mss = 0;
tm->tcpm_fastopen.syn_loss = 0;
tm->tcpm_fastopen.try_exp = 0;
tm->tcpm_fastopen.cookie.exp = false;
tm->tcpm_fastopen.cookie.len = 0;
+ write_sequnlock(&fastopen_seqlock);
}
}
#define TCP_METRICS_TIMEOUT (60 * 60 * HZ)
-static void tcpm_check_stamp(struct tcp_metrics_block *tm, struct dst_entry *dst)
+static void tcpm_check_stamp(struct tcp_metrics_block *tm,
+ const struct dst_entry *dst)
{
- if (tm && unlikely(time_after(jiffies, tm->tcpm_stamp + TCP_METRICS_TIMEOUT)))
+ unsigned long limit;
+
+ if (!tm)
+ return;
+ limit = READ_ONCE(tm->tcpm_stamp) + TCP_METRICS_TIMEOUT;
+ if (unlikely(time_after(jiffies, limit)))
tcpm_suck_dst(tm, dst, false);
}
@@ -174,20 +191,23 @@ static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
oldest = deref_locked(tcp_metrics_hash[hash].chain);
for (tm = deref_locked(oldest->tcpm_next); tm;
tm = deref_locked(tm->tcpm_next)) {
- if (time_before(tm->tcpm_stamp, oldest->tcpm_stamp))
+ if (time_before(READ_ONCE(tm->tcpm_stamp),
+ READ_ONCE(oldest->tcpm_stamp)))
oldest = tm;
}
tm = oldest;
} else {
- tm = kmalloc(sizeof(*tm), GFP_ATOMIC);
+ tm = kzalloc(sizeof(*tm), GFP_ATOMIC);
if (!tm)
goto out_unlock;
}
- write_pnet(&tm->tcpm_net, net);
+ /* Paired with the READ_ONCE() in tm_net() */
+ WRITE_ONCE(tm->tcpm_net, net);
+
tm->tcpm_saddr = *saddr;
tm->tcpm_daddr = *daddr;
- tcpm_suck_dst(tm, dst, true);
+ tcpm_suck_dst(tm, dst, reclaim);
if (likely(!reclaim)) {
tm->tcpm_next = tcp_metrics_hash[hash].chain;
@@ -431,7 +451,7 @@ void tcp_update_metrics(struct sock *sk)
tp->reordering);
}
}
- tm->tcpm_stamp = jiffies;
+ WRITE_ONCE(tm->tcpm_stamp, jiffies);
out_unlock:
rcu_read_unlock();
}
@@ -446,11 +466,15 @@ void tcp_init_metrics(struct sock *sk)
u32 val, crtt = 0; /* cached RTT scaled by 8 */
sk_dst_confirm(sk);
+ /* ssthresh may have been reduced unnecessarily during.
+ * 3WHS. Restore it back to its initial default.
+ */
+ tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
if (!dst)
goto reset;
rcu_read_lock();
- tm = tcp_get_metrics(sk, dst, true);
+ tm = tcp_get_metrics(sk, dst, false);
if (!tm) {
rcu_read_unlock();
goto reset;
@@ -464,11 +488,6 @@ void tcp_init_metrics(struct sock *sk)
tp->snd_ssthresh = val;
if (tp->snd_ssthresh > tp->snd_cwnd_clamp)
tp->snd_ssthresh = tp->snd_cwnd_clamp;
- } else {
- /* ssthresh may have been reduced unnecessarily during.
- * 3WHS. Restore it back to its initial default.
- */
- tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
}
val = tcp_metric_get(tm, TCP_METRIC_REORDERING);
if (val && tp->reordering != val)
@@ -544,8 +563,6 @@ bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst)
return ret;
}
-static DEFINE_SEQLOCK(fastopen_seqlock);
-
void tcp_fastopen_cache_get(struct sock *sk, u16 *mss,
struct tcp_fastopen_cookie *cookie)
{
@@ -652,7 +669,7 @@ static int tcp_metrics_fill_info(struct sk_buff *msg,
}
if (nla_put_msecs(msg, TCP_METRICS_ATTR_AGE,
- jiffies - tm->tcpm_stamp,
+ jiffies - READ_ONCE(tm->tcpm_stamp),
TCP_METRICS_ATTR_PAD) < 0)
goto nla_put_failure;
@@ -663,7 +680,7 @@ static int tcp_metrics_fill_info(struct sk_buff *msg,
if (!nest)
goto nla_put_failure;
for (i = 0; i < TCP_METRIC_MAX_KERNEL + 1; i++) {
- u32 val = tm->tcpm_vals[i];
+ u32 val = tcp_metric_get(tm, i);
if (!val)
continue;
@@ -895,7 +912,7 @@ static void tcp_metrics_flush_all(struct net *net)
match = net ? net_eq(tm_net(tm), net) :
!refcount_read(&tm_net(tm)->count);
if (match) {
- *pp = tm->tcpm_next;
+ rcu_assign_pointer(*pp, tm->tcpm_next);
kfree_rcu(tm, rcu_head);
} else {
pp = &tm->tcpm_next;
@@ -936,7 +953,7 @@ static int tcp_metrics_nl_cmd_del(struct sk_buff *skb, struct genl_info *info)
if (addr_same(&tm->tcpm_daddr, &daddr) &&
(!src || addr_same(&tm->tcpm_saddr, &saddr)) &&
net_eq(tm_net(tm), net)) {
- *pp = tm->tcpm_next;
+ rcu_assign_pointer(*pp, tm->tcpm_next);
kfree_rcu(tm, rcu_head);
found = true;
} else {
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-22 05:06:17 +0000