[PATCH 4.14 12/74] net: make socket read/write_iter() honor IOCB_NOWAIT

Greg Kroah-Hartman
2020-01-07T21:14:51Z

From: Jens Axboe <axboe@kernel.dk>

[ Upstream commit ebfcd8955c0b52eb793bcbc9e71140e3d0cdb228 ]

The socket read/write helpers only look at the file O_NONBLOCK. not
the iocb IOCB_NOWAIT flag. This breaks users like preadv2/pwritev2
and io_uring that rely on not having the file itself marked nonblocking,
but rather the iocb itself.

Cc: netdev@vger.kernel.org
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/socket.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/socket.c b/net/socket.c
index aab65277314d..5b134a6b6216 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -891,7 +891,7 @@ static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to)
.msg_iocb = iocb};
ssize_t res;

- if (file->f_flags & O_NONBLOCK)
+ if (file->f_flags & O_NONBLOCK || (iocb->ki_flags & IOCB_NOWAIT))
msg.msg_flags = MSG_DONTWAIT;

if (iocb->ki_pos != 0)
@@ -916,7 +916,7 @@ static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from)
if (iocb->ki_pos != 0)
return -ESPIPE;

- if (file->f_flags & O_NONBLOCK)
+ if (file->f_flags & O_NONBLOCK || (iocb->ki_flags & IOCB_NOWAIT))
msg.msg_flags = MSG_DONTWAIT;

if (sock->type == SOCK_SEQPACKET)
--
2.20.1