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Commit e92053a5 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

SUNRPC: Handle zero length fragments correctly 



A zero length fragment is really a bug, but let's ensure we don't
go nuts when one turns up.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent ae053551

net/sunrpc/xprtsock.c

+29 −14
Original line number Diff line number Diff line
@@ -405,8 +405,8 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags, 
	size_t want, seek_init = seek, offset = 0;

	ssize_t ret;



	if (seek < buf->head[0].iov_len) {

	want = min_t(size_t, count, buf->head[0].iov_len);

	if (seek < want) {

		ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);

		if (ret <= 0)

			goto sock_err;
@@ -417,8 +417,8 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags, 
			goto out;

		seek = 0;

	} else {

		seek -= buf->head[0].iov_len;

		offset += buf->head[0].iov_len;

		seek -= want;

		offset += want;

	}



	want = xs_alloc_sparse_pages(buf,
@@ -443,8 +443,8 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags, 
		offset += want;

	}



	if (seek < buf->tail[0].iov_len) {

	want = min_t(size_t, count - offset, buf->tail[0].iov_len);

	if (seek < want) {

		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);

		if (ret <= 0)

			goto sock_err;
@@ -454,7 +454,7 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags, 
		if (ret != want)

			goto out;

	} else

		offset += buf->tail[0].iov_len;

		offset = seek_init;

	ret = -EMSGSIZE;

out:

	*read = offset - seek_init;
@@ -482,6 +482,14 @@ xs_read_stream_request_done(struct sock_xprt *transport) 
	return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);

}



static void

xs_read_stream_check_eor(struct sock_xprt *transport,

		struct msghdr *msg)

{

	if (xs_read_stream_request_done(transport))

		msg->msg_flags |= MSG_EOR;

}



static ssize_t

xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,

		int flags, struct rpc_rqst *req)
@@ -493,17 +501,24 @@ xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg, 
	xs_read_header(transport, buf);



	want = transport->recv.len - transport->recv.offset;

	if (want != 0) {

		ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,

			transport->recv.copied + want, transport->recv.copied,

				transport->recv.copied + want,

				transport->recv.copied,

				&read);

		transport->recv.offset += read;

		transport->recv.copied += read;

	} else

		read = 0;



	if (transport->recv.offset == transport->recv.len) {

		if (xs_read_stream_request_done(transport))

			msg->msg_flags |= MSG_EOR;

		xs_read_stream_check_eor(transport, msg);

		return read;

	}



	if (want == 0)

		return 0;



	switch (ret) {

	default:

		break;