Commit 584a8c13 authored by Simon Derr's avatar Simon Derr Committed by Eric Van Hensbergen
Browse files

9P: Fix race in p9_write_work() 



See previous commit about p9_read_work() for details.

This fixes a similar race between p9_write_work() and p9_poll_mux()

Signed-off-by: default avatarSimon Derr <simon.derr@bull.net>
Signed-off-by: default avatarEric Van Hensbergen <ericvh@gmail.com>
parent 1957b3a8

net/9p/trans_fd.c

+10 −9
Original line number Diff line number Diff line
@@ -476,10 +476,9 @@ static void p9_write_work(struct work_struct *work) 
	clear_bit(Wpending, &m->wsched);

	err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);

	p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);

	if (err == -EAGAIN) {

		clear_bit(Wworksched, &m->wsched);

		return;

	}

	if (err == -EAGAIN)

		goto end_clear;





	if (err < 0)

		goto error;
@@ -492,19 +491,21 @@ static void p9_write_work(struct work_struct *work) 
	if (m->wpos == m->wsize)

		m->wpos = m->wsize = 0;



end_clear:

	clear_bit(Wworksched, &m->wsched);



	if (m->wsize || !list_empty(&m->unsent_req_list)) {

		if (test_and_clear_bit(Wpending, &m->wsched))

			n = POLLOUT;

		else

			n = p9_fd_poll(m->client, NULL);



		if (n & POLLOUT) {

		if ((n & POLLOUT) &&

		   !test_and_set_bit(Wworksched, &m->wsched)) {

			p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);

			schedule_work(&m->wq);

		} else

			clear_bit(Wworksched, &m->wsched);

	} else

		clear_bit(Wworksched, &m->wsched);

		}

	}



	return;