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: Simon Derr <simon.derr@bull.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
This commit is contained in:
Simon Derr 2012-09-17 15:16:30 +02:00 committed by Eric Van Hensbergen
parent 1957b3a86f
commit 584a8c13d5
1 changed files with 10 additions and 9 deletions

View File

@ -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;