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Merge branch 'mptcp-fixes'

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Mat Martineau says:

====================
mptcp: Miscellaneous fixes

Here are five changes we've collected and tested in the mptcp-tree:

Patch 1 changes handling of the MPTCP-level snd_next value during the
recovery phase after a subflow link failure.

Patches 2 and 3 are some small refactoring changes to replace some
open-coded bits.

Patch 4 removes an unused field in struct mptcp_sock.

Patch 5 restarts the MPTCP retransmit timer when there is
not-yet-transmitted data to send and all previously sent data has been
acknowledged. This prevents some sending stalls.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2021-09-25 11:36:51 +01:00
commit 24aa160d53
3 changed files with 56 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
net/mptcp/options.c
View File

@ -748,9 +748,7 @@ static bool mptcp_established_options_mp_prio(struct sock *sk,
/* can't send MP_PRIO with MPC, as they share the same option space:
* 'backup'. Also it makes no sense at all
*/
if (!subflow->send_mp_prio ||
((OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK |
OPTION_MPTCP_MPC_ACK) & opts->suboptions))
if (!subflow->send_mp_prio || (opts->suboptions & OPTIONS_MPTCP_MPC))
return false;
/* account for the trailing 'nop' option */
@ -1019,11 +1017,9 @@ static void ack_update_msk(struct mptcp_sock *msk,
old_snd_una = msk->snd_una;
new_snd_una = mptcp_expand_seq(old_snd_una, mp_opt->data_ack, mp_opt->ack64);
/* ACK for data not even sent yet and even above recovery bound? Ignore.*/
if (unlikely(after64(new_snd_una, snd_nxt))) {
if (!msk->recovery || after64(new_snd_una, msk->recovery_snd_nxt))
new_snd_una = old_snd_una;
}
/* ACK for data not even sent yet? Ignore.*/
if (unlikely(after64(new_snd_una, snd_nxt)))
new_snd_una = old_snd_una;
new_wnd_end = new_snd_una + tcp_sk(ssk)->snd_wnd;
@ -1329,8 +1325,7 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
TCPOPT_NOP << 8 | TCPOPT_NOP, ptr);
}
}
} else if ((OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK |
OPTION_MPTCP_MPC_ACK) & opts->suboptions) {
} else if (OPTIONS_MPTCP_MPC & opts->suboptions) {
u8 len, flag = MPTCP_CAP_HMAC_SHA256;
if (OPTION_MPTCP_MPC_SYN & opts->suboptions) {

75
net/mptcp/protocol.c
View File

@ -956,9 +956,7 @@ static void __mptcp_update_wmem(struct sock *sk)
{
struct mptcp_sock *msk = mptcp_sk(sk);
#ifdef CONFIG_LOCKDEP
WARN_ON_ONCE(!lockdep_is_held(&sk->sk_lock.slock));
#endif
lockdep_assert_held_once(&sk->sk_lock.slock);
if (!msk->wmem_reserved)
return;
@ -1107,7 +1105,8 @@ out:
if (cleaned && tcp_under_memory_pressure(sk))
__mptcp_mem_reclaim_partial(sk);
if (snd_una == READ_ONCE(msk->snd_nxt) && !msk->recovery) {
if (snd_una == READ_ONCE(msk->snd_nxt) &&
snd_una == READ_ONCE(msk->write_seq)) {
if (mptcp_timer_pending(sk) && !mptcp_data_fin_enabled(msk))
mptcp_stop_timer(sk);
} else {
@ -1117,9 +1116,8 @@ out:
static void __mptcp_clean_una_wakeup(struct sock *sk)
{
#ifdef CONFIG_LOCKDEP
WARN_ON_ONCE(!lockdep_is_held(&sk->sk_lock.slock));
#endif
lockdep_assert_held_once(&sk->sk_lock.slock);
__mptcp_clean_una(sk);
mptcp_write_space(sk);
}
@ -1525,6 +1523,38 @@ static void mptcp_push_release(struct sock *sk, struct sock *ssk,
release_sock(ssk);
}
static void mptcp_update_post_push(struct mptcp_sock *msk,
struct mptcp_data_frag *dfrag,
u32 sent)
{
u64 snd_nxt_new = dfrag->data_seq;
dfrag->already_sent += sent;
msk->snd_burst -= sent;
snd_nxt_new += dfrag->already_sent;
/* snd_nxt_new can be smaller than snd_nxt in case mptcp
* is recovering after a failover. In that event, this re-sends
* old segments.
*
* Thus compute snd_nxt_new candidate based on
* the dfrag->data_seq that was sent and the data
* that has been handed to the subflow for transmission
* and skip update in case it was old dfrag.
*/
if (likely(after64(snd_nxt_new, msk->snd_nxt)))
msk->snd_nxt = snd_nxt_new;
}
static void mptcp_check_and_set_pending(struct sock *sk)
{
if (mptcp_send_head(sk) &&
!test_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->flags))
set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->flags);
}
void __mptcp_push_pending(struct sock *sk, unsigned int flags)
{
struct sock *prev_ssk = NULL, *ssk = NULL;
@ -1568,12 +1598,10 @@ void __mptcp_push_pending(struct sock *sk, unsigned int flags)
}
info.sent += ret;
dfrag->already_sent += ret;
msk->snd_nxt += ret;
msk->snd_burst -= ret;
msk->tx_pending_data -= ret;
copied += ret;
len -= ret;
mptcp_update_post_push(msk, dfrag, ret);
}
WRITE_ONCE(msk->first_pending, mptcp_send_next(sk));
}
@ -1626,13 +1654,11 @@ static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk)
goto out;
info.sent += ret;
dfrag->already_sent += ret;
msk->snd_nxt += ret;
msk->snd_burst -= ret;
msk->tx_pending_data -= ret;
copied += ret;
len -= ret;
first = false;
mptcp_update_post_push(msk, dfrag, ret);
}
WRITE_ONCE(msk->first_pending, mptcp_send_next(sk));
}
@ -1742,7 +1768,6 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
frag_truesize += psize;
pfrag->offset += frag_truesize;
WRITE_ONCE(msk->write_seq, msk->write_seq + psize);
msk->tx_pending_data += psize;
/* charge data on mptcp pending queue to the msk socket
* Note: we charge such data both to sk and ssk
@ -2230,15 +2255,11 @@ bool __mptcp_retransmit_pending_data(struct sock *sk)
return false;
}
/* will accept ack for reijected data before re-sending them */
if (!msk->recovery || after64(msk->snd_nxt, msk->recovery_snd_nxt))
msk->recovery_snd_nxt = msk->snd_nxt;
msk->recovery_snd_nxt = msk->snd_nxt;
msk->recovery = true;
mptcp_data_unlock(sk);
msk->first_pending = rtx_head;
msk->tx_pending_data += msk->snd_nxt - rtx_head->data_seq;
msk->snd_nxt = rtx_head->data_seq;
msk->snd_burst = 0;
/* be sure to clear the "sent status" on all re-injected fragments */
@ -2401,6 +2422,9 @@ static void __mptcp_retrans(struct sock *sk)
int ret;
mptcp_clean_una_wakeup(sk);
/* first check ssk: need to kick "stale" logic */
ssk = mptcp_subflow_get_retrans(msk);
dfrag = mptcp_rtx_head(sk);
if (!dfrag) {
if (mptcp_data_fin_enabled(msk)) {
@ -2413,10 +2437,12 @@ static void __mptcp_retrans(struct sock *sk)
goto reset_timer;
}
return;
if (!mptcp_send_head(sk))
return;
goto reset_timer;
}
ssk = mptcp_subflow_get_retrans(msk);
if (!ssk)
goto reset_timer;
@ -2443,6 +2469,8 @@ static void __mptcp_retrans(struct sock *sk)
release_sock(ssk);
reset_timer:
mptcp_check_and_set_pending(sk);
if (!mptcp_timer_pending(sk))
mptcp_reset_timer(sk);
}
@ -2509,7 +2537,6 @@ static int __mptcp_init_sock(struct sock *sk)
msk->first_pending = NULL;
msk->wmem_reserved = 0;
WRITE_ONCE(msk->rmem_released, 0);
msk->tx_pending_data = 0;
msk->timer_ival = TCP_RTO_MIN;
msk->first = NULL;

1
net/mptcp/protocol.h
View File

@ -254,7 +254,6 @@ struct mptcp_sock {
struct sk_buff *ooo_last_skb;
struct rb_root out_of_order_queue;
struct sk_buff_head receive_queue;
int tx_pending_data;
struct list_head conn_list;
struct list_head rtx_queue;
struct mptcp_data_frag *first_pending;