md: replace R5_WantPrexor with R5_WantDrain, add 'prexor' reconstruct_states

From: Dan Williams <dan.j.williams@intel.com>

Currently ops_run_biodrain and other locations have extra logic to determine
which blocks are processed in the prexor and non-prexor cases.  This can be
eliminated if handle_write_operations5 flags the blocks to be processed in all
cases via R5_Wantdrain.  The presence of the prexor operation is tracked in
sh->reconstruct_state.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Neil Brown <neilb@suse.de>

1 files changed, 3 insertions, 3 deletions

diff --git a/include/linux/raid/raid5.h b/include/linux/raid/raid5.h
index 5f3e674b87d..3b267279245 100644
--- a/include/linux/raid/raid5.h
+++ b/include/linux/raid/raid5.h
@@ -187,8 +187,10 @@ enum check_states {
  */
 enum reconstruct_states {
         reconstruct_state_idle = 0,
+        reconstruct_state_prexor_drain_run,     /* prexor-write */
         reconstruct_state_drain_run,            /* write */
         reconstruct_state_run,                  /* expand */
+        reconstruct_state_prexor_drain_result,
         reconstruct_state_drain_result,
         reconstruct_state_result,
 };
@@ -258,9 +260,7 @@ struct r6_state {
 #define R5_Wantfill     12 /* dev->toread contains a bio that needs
                                     * filling
                                     */
-#define R5_Wantprexor   13 /* distinguish blocks ready for rmw from
-                                    * other "towrites"
-                                    */
+#define R5_Wantdrain    13 /* dev->towrite needs to be drained */
 /*
  * Write method
  */