[ 204/221] ceph: dont reference req after put

Greg Kroah-Hartman
2013-01-15T22:41:35Z

From: Alex Elder <elder@inktank.com>

(cherry picked from commit 7d5f24812bd182a2471cb69c1c2baf0648332e1f)

In __unregister_request(), there is a call to list_del_init()
referencing a request that was the subject of a call to
ceph_osdc_put_request() on the previous line. This is not
safe, because the request structure could have been freed
by the time we reach the list_del_init().

Fix this by reversing the order of these lines.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-off-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ceph/osd_client.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -873,9 +873,9 @@ static void __unregister_request(struct
req->r_osd = NULL;
}

+ list_del_init(&req->r_req_lru_item);
ceph_osdc_put_request(req);

- list_del_init(&req->r_req_lru_item);
if (osdc->num_requests == 0) {
dout(" no requests, canceling timeout\n");
__cancel_osd_timeout(osdc);