From c443305529d1d3d3bee0d68fdd14ae89835e091f Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 4 Dec 2018 07:52:11 -0500 Subject: SUNRPC: Fix RPC receive hangs The RPC code is occasionally hanging when the receive code fails to empty the socket buffer due to a partial read of the data. When we convert that to an EAGAIN, it appears we occasionally leave data in the socket. The fix is to just keep reading until the socket returns EAGAIN/EWOULDBLOCK. Reported-by: Catalin Marinas Reported-by: Cristian Marussi Reported-by: Chuck Lever Signed-off-by: Trond Myklebust Tested-by: Catalin Marinas Tested-by: Cristian Marussi --- net/sunrpc/xprtsock.c | 39 +++++++++++++++++++-------------------- 1 file changed, 19 insertions(+), 20 deletions(-) (limited to 'net') diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index ae77c71c1f64..0898752cecfe 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -398,7 +398,7 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags, if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC)) goto out; if (ret != want) - goto eagain; + goto out; seek = 0; } else { seek -= buf->head[0].iov_len; @@ -418,7 +418,7 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags, if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC)) goto out; if (ret != want) - goto eagain; + goto out; seek = 0; } else { seek -= buf->page_len; @@ -433,7 +433,7 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags, if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC)) goto out; if (ret != want) - goto eagain; + goto out; } else offset += buf->tail[0].iov_len; ret = -EMSGSIZE; @@ -441,9 +441,6 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags, out: *read = offset - seek_init; return ret; -eagain: - ret = -EAGAIN; - goto out; sock_err: offset += seek; goto out; @@ -486,19 +483,18 @@ xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg, if (transport->recv.offset == transport->recv.len) { if (xs_read_stream_request_done(transport)) msg->msg_flags |= MSG_EOR; - return transport->recv.copied; + return read; } switch (ret) { + default: + break; case -EMSGSIZE: - return transport->recv.copied; + return read; case 0: return -ESHUTDOWN; - default: - if (ret < 0) - return ret; } - return -EAGAIN; + return ret < 0 ? ret : read; } static size_t @@ -537,7 +533,7 @@ xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags) ret = xs_read_stream_request(transport, msg, flags, req); if (msg->msg_flags & (MSG_EOR|MSG_TRUNC)) - xprt_complete_bc_request(req, ret); + xprt_complete_bc_request(req, transport->recv.copied); return ret; } @@ -570,7 +566,7 @@ xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags) spin_lock(&xprt->queue_lock); if (msg->msg_flags & (MSG_EOR|MSG_TRUNC)) - xprt_complete_rqst(req->rq_task, ret); + xprt_complete_rqst(req->rq_task, transport->recv.copied); xprt_unpin_rqst(req); out: spin_unlock(&xprt->queue_lock); @@ -591,10 +587,8 @@ xs_read_stream(struct sock_xprt *transport, int flags) if (ret <= 0) goto out_err; transport->recv.offset = ret; - if (ret != want) { - ret = -EAGAIN; - goto out_err; - } + if (transport->recv.offset != want) + return transport->recv.offset; transport->recv.len = be32_to_cpu(transport->recv.fraghdr) & RPC_FRAGMENT_SIZE_MASK; transport->recv.offset -= sizeof(transport->recv.fraghdr); @@ -602,6 +596,9 @@ xs_read_stream(struct sock_xprt *transport, int flags) } switch (be32_to_cpu(transport->recv.calldir)) { + default: + msg.msg_flags |= MSG_TRUNC; + break; case RPC_CALL: ret = xs_read_stream_call(transport, &msg, flags); break; @@ -616,6 +613,8 @@ xs_read_stream(struct sock_xprt *transport, int flags) goto out_err; read += ret; if (transport->recv.offset < transport->recv.len) { + if (!(msg.msg_flags & MSG_TRUNC)) + return read; ret = xs_read_discard(transport->sock, &msg, flags, transport->recv.len - transport->recv.offset); if (ret <= 0) @@ -623,7 +622,7 @@ xs_read_stream(struct sock_xprt *transport, int flags) transport->recv.offset += ret; read += ret; if (transport->recv.offset != transport->recv.len) - return -EAGAIN; + return read; } if (xs_read_stream_request_done(transport)) { trace_xs_stream_read_request(transport); @@ -653,7 +652,7 @@ static void xs_stream_data_receive(struct sock_xprt *transport) clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state); for (;;) { ret = xs_read_stream(transport, MSG_DONTWAIT); - if (ret <= 0) + if (ret < 0) break; read += ret; cond_resched(); -- cgit v1.2.3