libceph: drop mutex on error in handle_reply()

The osd client mutex is acquired just before getting a reference to
a request in handle_reply().  However the error paths after that
don't drop the mutex before returning as they should.

Drop the mutex after dropping the request reference.  Also add a
bad_mutex label at that point and use it so the failed request
lookup case can be handled with the rest.

This resolves:
    http://tracker.ceph.com/issues/4615

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 55f7c9a57a43..69ef6539ca14 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1337,8 +1337,7 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
         req = __lookup_request(osdc, tid);
         if (req == NULL) {
                 dout("handle_reply tid %llu dne\n", tid);
-                mutex_unlock(&osdc->request_mutex);
-                return;
+                goto bad_mutex;
         }
         ceph_osdc_get_request(req);
 
@@ -1437,6 +1436,8 @@ done:
 
 bad_put:
         ceph_osdc_put_request(req);
+bad_mutex:
+        mutex_unlock(&osdc->request_mutex);
 bad:
         pr_err("corrupt osd_op_reply got %d %d\n",
                (int)msg->front.iov_len, le32_to_cpu(msg->hdr.front_len));