gfs2: Fix loop in gfs2_rbm_find

commit 2d29f6b96d8f80322ed2dd895bca590491c38d34 upstream.

Fix the resource group wrap-around logic in gfs2_rbm_find that commit
e579ed4f44 broke.  The bug can lead to unnecessary repeated scanning of the
same bitmaps; there is a risk that future changes will turn this into an
endless loop.

Fixes: e579ed4f44 ("GFS2: Introduce rbm field bii")
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index b0eee90738ff468fa11e2e8c64d483ce409db207..914cb3d72ddf3a16ed8a97e10739502ca88092fa 100644 (file)
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -1695,9 +1695,9 @@ static int gfs2_rbm_find(struct gfs2_rbm *rbm, u8 state, u32 *minext,
                        goto next_iter;
                }
                if (ret == -E2BIG) {
+                       n += rbm->bii - initial_bii;
                        rbm->bii = 0;
                        rbm->offset = 0;
-                       n += (rbm->bii - initial_bii);
                        goto res_covered_end_of_rgrp;
                }
                return ret;