diff options
| author | Jason Wang <jasowang@redhat.com> | 2018-02-07 17:14:46 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-02-08 14:10:30 -0500 |
| commit | 762c330d670e3d4b795cf7a8d761866fdd1eef49 (patch) | |
| tree | 249dbef044fc3ecf0b3f2d449e63080e9f802359 /drivers/net/tun.c | |
| parent | cb9f7a9a5c96a773bbc9c70660dc600cfff82f82 (diff) | |
| download | linux-762c330d670e3d4b795cf7a8d761866fdd1eef49.tar.bz2 | |
tuntap: add missing xdp flush
When using devmap to redirect packets between interfaces,
xdp_do_flush() is usually a must to flush any batched
packets. Unfortunately this is missed in current tuntap
implementation.
Unlike most hardware driver which did XDP inside NAPI loop and call
xdp_do_flush() at then end of each round of poll. TAP did it in the
context of process e.g tun_get_user(). So fix this by count the
pending redirected packets and flush when it exceeds NAPI_POLL_WEIGHT
or MSG_MORE was cleared by sendmsg() caller.
With this fix, xdp_redirect_map works again between two TAPs.
Fixes: 761876c857cb ("tap: XDP support")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/tun.c')
| -rw-r--r-- | drivers/net/tun.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 0dc66e4fbb2c..17e496b88f81 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -181,6 +181,7 @@ struct tun_file { struct tun_struct *detached; struct ptr_ring tx_ring; struct xdp_rxq_info xdp_rxq; + int xdp_pending_pkts; }; struct tun_flow_entry { @@ -1665,6 +1666,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, case XDP_REDIRECT: get_page(alloc_frag->page); alloc_frag->offset += buflen; + ++tfile->xdp_pending_pkts; err = xdp_do_redirect(tun->dev, &xdp, xdp_prog); if (err) goto err_redirect; @@ -1986,6 +1988,11 @@ static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from) result = tun_get_user(tun, tfile, NULL, from, file->f_flags & O_NONBLOCK, false); + if (tfile->xdp_pending_pkts) { + tfile->xdp_pending_pkts = 0; + xdp_do_flush_map(); + } + tun_put(tun); return result; } @@ -2322,6 +2329,13 @@ static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) ret = tun_get_user(tun, tfile, m->msg_control, &m->msg_iter, m->msg_flags & MSG_DONTWAIT, m->msg_flags & MSG_MORE); + + if (tfile->xdp_pending_pkts >= NAPI_POLL_WEIGHT || + !(m->msg_flags & MSG_MORE)) { + tfile->xdp_pending_pkts = 0; + xdp_do_flush_map(); + } + tun_put(tun); return ret; } @@ -3153,6 +3167,7 @@ static int tun_chr_open(struct inode *inode, struct file * file) sock_set_flag(&tfile->sk, SOCK_ZEROCOPY); memset(&tfile->tx_ring, 0, sizeof(tfile->tx_ring)); + tfile->xdp_pending_pkts = 0; return 0; } |