So the scm_stat_{add,del} helper can be invoked with no
additional lock held.This clean-up the code a bit and will make the next patch easier. Signed-off-by: Paolo Abeni <[email protected]> Reviewed-by: Kirill Tkhai <[email protected]> Signed-off-by: David S. Miller <[email protected]> (cherry picked from commit 7782040b950b5d0433f734fb2bba8b8b5ed6ce5a) Signed-off-by: Vasily Averin <[email protected]> --- include/net/af_unix.h | 2 +- net/unix/af_unix.c | 21 ++++++--------------- 2 files changed, 7 insertions(+), 16 deletions(-) diff --git a/include/net/af_unix.h b/include/net/af_unix.h index a10e2c52bf9b..7e9f8bf14151 100644 --- a/include/net/af_unix.h +++ b/include/net/af_unix.h @@ -42,7 +42,7 @@ struct unix_skb_parms { } __randomize_layout; struct scm_stat { - u32 nr_fds; + atomic_t nr_fds; }; #define UNIXCB(skb) (*(struct unix_skb_parms *)&((skb)->cb)) diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index acd7985d1faa..f0b53ddd76b4 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -681,7 +681,8 @@ static void unix_show_fdinfo(struct seq_file *m, struct socket *sock) if (sk) { u = unix_sk(sock->sk); - seq_printf(m, "scm_fds: %u\n", READ_ONCE(u->scm_stat.nr_fds)); + seq_printf(m, "scm_fds: %u\n", + atomic_read(&u->scm_stat.nr_fds)); } } #else @@ -1573,10 +1574,8 @@ static void scm_stat_add(struct sock *sk, struct sk_buff *skb) struct scm_fp_list *fp = UNIXCB(skb).fp; struct unix_sock *u = unix_sk(sk); - lockdep_assert_held(&sk->sk_receive_queue.lock); - if (unlikely(fp && fp->count)) - u->scm_stat.nr_fds += fp->count; + atomic_add(fp->count, &u->scm_stat.nr_fds); } static void scm_stat_del(struct sock *sk, struct sk_buff *skb) @@ -1584,10 +1583,8 @@ static void scm_stat_del(struct sock *sk, struct sk_buff *skb) struct scm_fp_list *fp = UNIXCB(skb).fp; struct unix_sock *u = unix_sk(sk); - lockdep_assert_held(&sk->sk_receive_queue.lock); - if (unlikely(fp && fp->count)) - u->scm_stat.nr_fds -= fp->count; + atomic_sub(fp->count, &u->scm_stat.nr_fds); } /* @@ -1775,10 +1772,8 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg, if (sock_flag(other, SOCK_RCVTSTAMP)) __net_timestamp(skb); maybe_add_creds(skb, sock, other); - spin_lock(&other->sk_receive_queue.lock); scm_stat_add(other, skb); - __skb_queue_tail(&other->sk_receive_queue, skb); - spin_unlock(&other->sk_receive_queue.lock); + skb_queue_tail(&other->sk_receive_queue, skb); unix_state_unlock(other); other->sk_data_ready(other); sock_put(other); @@ -1880,10 +1875,8 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, goto pipe_err_free; maybe_add_creds(skb, sock, other); - spin_lock(&other->sk_receive_queue.lock); scm_stat_add(other, skb); - __skb_queue_tail(&other->sk_receive_queue, skb); - spin_unlock(&other->sk_receive_queue.lock); + skb_queue_tail(&other->sk_receive_queue, skb); unix_state_unlock(other); other->sk_data_ready(other); sent += size; @@ -2379,9 +2372,7 @@ static int unix_stream_read_generic(struct unix_stream_read_state *state, sk_peek_offset_bwd(sk, chunk); if (UNIXCB(skb).fp) { - spin_lock(&sk->sk_receive_queue.lock); scm_stat_del(sk, skb); - spin_unlock(&sk->sk_receive_queue.lock); unix_detach_fds(&scm, skb); } -- 2.25.1 _______________________________________________ Devel mailing list [email protected] https://lists.openvz.org/mailman/listinfo/devel
