diff options
author | Eric Dumazet <edumazet@google.com> | 2016-11-04 21:54:32 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2016-11-09 21:02:27 +0300 |
commit | 67db3e4bfbc90657c7be840aad5585be46240d6f (patch) | |
tree | bf67250bf31cf1d0f05a696688efdf26d9033324 /net/ipv4/tcp_input.c | |
parent | ccbf3bfaee0e4f1ddf8103884fd4bf9f35f31f08 (diff) | |
download | linux-67db3e4bfbc90657c7be840aad5585be46240d6f.tar.xz |
tcp: no longer hold ehash lock while calling tcp_get_info()
We had various problems in the past in tcp_get_info() and used
specific synchronization to avoid deadlocks.
We would like to add more instrumentation points for TCP, and
avoiding grabing socket lock in tcp_getinfo() was too costly.
Being able to lock the socket allows to provide consistent set
of fields.
inet_diag_dump_icsk() can make sure ehash locks are not
held any more when tcp_get_info() is called.
We can remove syncp added in commit d654976cbf85
("tcp: fix a potential deadlock in tcp_get_info()"), but we need
to use lock_sock_fast() instead of spin_lock_bh() since TCP input
path can now be run from process context.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r-- | net/ipv4/tcp_input.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index f2c59c8e57ff..a70046fea0e8 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3351,9 +3351,7 @@ static void tcp_snd_una_update(struct tcp_sock *tp, u32 ack) u32 delta = ack - tp->snd_una; sock_owned_by_me((struct sock *)tp); - u64_stats_update_begin_raw(&tp->syncp); tp->bytes_acked += delta; - u64_stats_update_end_raw(&tp->syncp); tp->snd_una = ack; } @@ -3363,9 +3361,7 @@ static void tcp_rcv_nxt_update(struct tcp_sock *tp, u32 seq) u32 delta = seq - tp->rcv_nxt; sock_owned_by_me((struct sock *)tp); - u64_stats_update_begin_raw(&tp->syncp); tp->bytes_received += delta; - u64_stats_update_end_raw(&tp->syncp); tp->rcv_nxt = seq; } |