xenbus: req->err should be updated before req->state

This patch adds the barrier to guarantee that req->err is always updated
before req->state.

Otherwise, read_reply() would not return ERR_PTR(req->err) but
req->body, when process_writes()->xb_write() is failed.

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Link: https://lore.kernel.org/r/20200303221423.21962-2-dongli.zhang@oracle.com
Reviewed-by: Julien Grall <jgrall@amazon.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
This commit is contained in:
Dongli Zhang 2020-03-03 14:14:23 -08:00 committed by Boris Ostrovsky
parent 1b6a51e86c
commit 8130b9d5b5
1 changed files with 2 additions and 0 deletions

View File

@ -397,6 +397,8 @@ static int process_writes(void)
if (state.req->state == xb_req_state_aborted)
kfree(state.req);
else {
/* write err, then update state */
virt_wmb();
state.req->state = xb_req_state_got_reply;
wake_up(&state.req->wq);
}