gfs2: Add gfs2_blk2rgrpd comment and fix incorrect use
Document when to use gfs2_blk2rgrpd for "inexact" resource group
matching. Based on that, fix an incorrect use of gfs2_blk2rgrpd in
sweep_bh_for_rgrps.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 95b2a57..211d7a5 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -489,6 +489,13 @@ void gfs2_rgrp_verify(struct gfs2_rgrpd *rgd)
* @blk: The data block number
* @exact: True if this needs to be an exact match
*
+ * The @exact argument should be set to true by most callers. The exception
+ * is when we need to match blocks which are not represented by the rgrp
+ * bitmap, but which are part of the rgrp (i.e. padding blocks) which are
+ * there for alignment purposes. Another way of looking at it is that @exact
+ * matches only valid data/metadata blocks, but with @exact false, it will
+ * match any block within the extent of the rgrp.
+ *
* Returns: The resource group, or NULL if not found
*/