libceph: fix linger request requeuing
The r_req_lru_item list node moves between several lists, and that cycle
is not directly related (and does not begin) with __register_request().
Initialize it in the request constructor, not __register_request(). This
fixes later badness (below) when OSDs restart underneath an rbd mount.
Crashes we've seen due to this include:
[ 213.974288] kernel BUG at net/ceph/messenger.c:2193!
and
[ 144.035274] BUG: unable to handle kernel NULL pointer dereference at 0000000000000048
[ 144.035278] IP: [<ffffffffa036c053>] con_work+0x1463/0x2ce0 [libceph]
Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 16836a7..88ad8a2 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -217,6 +217,7 @@
INIT_LIST_HEAD(&req->r_unsafe_item);
INIT_LIST_HEAD(&req->r_linger_item);
INIT_LIST_HEAD(&req->r_linger_osd);
+ INIT_LIST_HEAD(&req->r_req_lru_item);
req->r_flags = flags;
WARN_ON((flags & (CEPH_OSD_FLAG_READ|CEPH_OSD_FLAG_WRITE)) == 0);
@@ -816,13 +817,10 @@
{
req->r_tid = ++osdc->last_tid;
req->r_request->hdr.tid = cpu_to_le64(req->r_tid);
- INIT_LIST_HEAD(&req->r_req_lru_item);
-
dout("__register_request %p tid %lld\n", req, req->r_tid);
__insert_request(osdc, req);
ceph_osdc_get_request(req);
osdc->num_requests++;
-
if (osdc->num_requests == 1) {
dout(" first request, scheduling timeout\n");
__schedule_osd_timeout(osdc);