Merge branch 'punch-hole' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2.git

fs/gfs2/rgrp.c

@@ -490,6 +490,13 @@ 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
  */