ceph: unregister osd request on failure

The osd request wasn't being unregistered when the osd returned a failure
code, even though the result was returned to the caller.  This would cause
it to eventually time out, and then crash the kernel when it tried to
resend the request using a stale page vector.
Signed-off-by: Sage Weil <sage@newdream.net>

fs/ceph/osd_client.c

@@ -779,16 +779,18 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
 	struct ceph_osd_request *req;
 	u64 tid;
 	int numops, object_len, flags;
+	s32 result;
 
 	tid = le64_to_cpu(msg->hdr.tid);
 	if (msg->front.iov_len < sizeof(*rhead))
 		goto bad;
 	numops = le32_to_cpu(rhead->num_ops);
 	object_len = le32_to_cpu(rhead->object_len);
+	result = le32_to_cpu(rhead->result);
 	if (msg->front.iov_len != sizeof(*rhead) + object_len +
 	    numops * sizeof(struct ceph_osd_op))
 		goto bad;
-	dout("handle_reply %p tid %llu\n", msg, tid);
+	dout("handle_reply %p tid %llu result %d\n", msg, tid, (int)result);
 
 	/* lookup */
 	mutex_lock(&osdc->request_mutex);
@@ -834,7 +836,8 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
 	dout("handle_reply tid %llu flags %d\n", tid, flags);
 
 	/* either this is a read, or we got the safe response */
-	if ((flags & CEPH_OSD_FLAG_ONDISK) ||
+	if (result < 0 ||
+	    (flags & CEPH_OSD_FLAG_ONDISK) ||
 	    ((flags & CEPH_OSD_FLAG_WRITE) == 0))
 		__unregister_request(osdc, req);