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authorDavid S. Miller <davem@davemloft.net>2018-05-26 19:46:15 -0400
committerDavid S. Miller <davem@davemloft.net>2018-05-26 19:46:15 -0400
commit5b79c2af667c0e2684f2a6dbf6439074b78f490c (patch)
treeefda2b94317c914fef0bfb25fe5ada9e253d5415 /drivers/net/tun.c
parente52cde71709348c0d67bf0f213b438fa4d6cf9a9 (diff)
parentbc2dbc5420e82560e650f8531ceca597441ca171 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Lots of easy overlapping changes in the confict resolutions here. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/tun.c')
-rw-r--r--drivers/net/tun.c19
1 files changed, 15 insertions, 4 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 33a9c5661038..2265d2ccea47 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1436,6 +1436,13 @@ static void tun_net_init(struct net_device *dev)
dev->max_mtu = MAX_MTU - dev->hard_header_len;
}
+static bool tun_sock_writeable(struct tun_struct *tun, struct tun_file *tfile)
+{
+ struct sock *sk = tfile->socket.sk;
+
+ return (tun->dev->flags & IFF_UP) && sock_writeable(sk);
+}
+
/* Character device part */
/* Poll */
@@ -1458,10 +1465,14 @@ static __poll_t tun_chr_poll(struct file *file, poll_table *wait)
if (!ptr_ring_empty(&tfile->tx_ring))
mask |= EPOLLIN | EPOLLRDNORM;
- if (tun->dev->flags & IFF_UP &&
- (sock_writeable(sk) ||
- (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
- sock_writeable(sk))))
+ /* Make sure SOCKWQ_ASYNC_NOSPACE is set if not writable to
+ * guarantee EPOLLOUT to be raised by either here or
+ * tun_sock_write_space(). Then process could get notification
+ * after it writes to a down device and meets -EIO.
+ */
+ if (tun_sock_writeable(tun, tfile) ||
+ (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
+ tun_sock_writeable(tun, tfile)))
mask |= EPOLLOUT | EPOLLWRNORM;
if (tun->dev->reg_state != NETREG_REGISTERED)