libceph: fix a osd request memory leak

If an invalid layout is provided to ceph_osdc_new_request(), its
call to calc_layout() might return an error.  At that point in the
function we've already allocated an osd request structure, so we
need to free it (drop a reference) in the event such an error
occurs.

The only other value calc_layout() will return is 0, so make that
explicit in the successful case.

This resolves:
    http://tracker.ceph.com/issues/4240

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index d730dd4d8eb28bc421babb138f187605ee7c0ec6..cf4e15bfe0db316f0ed7c1e75404ad6341389785 100644 (file)
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -109,7 +109,7 @@ static int calc_layout(struct ceph_vino vino,
        snprintf(req->r_oid, sizeof(req->r_oid), "%llx.%08llx", vino.ino, bno);
        req->r_oid_len = strlen(req->r_oid);
 
-       return r;
+       return 0;
 }
 
 /*
@@ -470,8 +470,10 @@ struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *osdc,
 
        /* calculate max write size */
        r = calc_layout(vino, layout, off, plen, req, ops);
-       if (r < 0)
+       if (r < 0) {
+               ceph_osdc_put_request(req);
                return ERR_PTR(r);
+       }
        req->r_file_layout = *layout;  /* keep a copy */
 
        /* in case it differs from natural (file) alignment that