diff options
Diffstat (limited to 'net/9p/trans_fd.c')
| -rw-r--r-- | net/9p/trans_fd.c | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c index c4015f30f9fa..1a3948b8c493 100644 --- a/net/9p/trans_fd.c +++ b/net/9p/trans_fd.c @@ -671,10 +671,14 @@ static int p9_fd_request(struct p9_client *client, struct p9_req_t *req) p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", m, current, &req->tc, req->tc.id); - if (m->err < 0) - return m->err; spin_lock(&m->req_lock); + + if (m->err < 0) { + spin_unlock(&m->req_lock); + return m->err; + } + WRITE_ONCE(req->status, REQ_STATUS_UNSENT); list_add_tail(&req->req_list, &m->unsent_req_list); spin_unlock(&m->req_lock); @@ -832,14 +836,21 @@ static int p9_fd_open(struct p9_client *client, int rfd, int wfd) goto out_free_ts; if (!(ts->rd->f_mode & FMODE_READ)) goto out_put_rd; - /* prevent workers from hanging on IO when fd is a pipe */ - ts->rd->f_flags |= O_NONBLOCK; + /* Prevent workers from hanging on IO when fd is a pipe. + * It's technically possible for userspace or concurrent mounts to + * modify this flag concurrently, which will likely result in a + * broken filesystem. However, just having bad flags here should + * not crash the kernel or cause any other sort of bug, so mark this + * particular data race as intentional so that tooling (like KCSAN) + * can allow it and detect further problems. + */ + data_race(ts->rd->f_flags |= O_NONBLOCK); ts->wr = fget(wfd); if (!ts->wr) goto out_put_rd; if (!(ts->wr->f_mode & FMODE_WRITE)) goto out_put_wr; - ts->wr->f_flags |= O_NONBLOCK; + data_race(ts->wr->f_flags |= O_NONBLOCK); client->trans = ts; client->status = Connected; |