MD: Remember the last sync operation that was performed

MD:  Remember the last sync operation that was performed

This patch adds a field to the mddev structure to track the last
sync operation that was performed.  This is especially useful when
it comes to what is recorded in mismatch_cnt in sysfs.  If the
last operation was "data-check", then it reports the number of
descrepancies found by the user-initiated check.  If it was a
"repair" operation, then it is reporting the number of
descrepancies repaired.  etc.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/md/md.h b/drivers/md/md.h
index 653f992b687a..20f02c0b5f2d 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -268,6 +268,14 @@ struct mddev {
 
         struct md_thread                *thread;        /* management thread */
         struct md_thread                *sync_thread;   /* doing resync or reconstruct */
+
+        /* 'last_sync_action' is initialized to "none".  It is set when a
+         * sync operation (i.e "data-check", "requested-resync", "resync",
+         * "recovery", or "reshape") is started.  It holds this value even
+         * when the sync thread is "frozen" (interrupted) or "idle" (stopped
+         * or finished).  It is overwritten when a new sync operation is begun.
+         */
+        char                            *last_sync_action;
         sector_t                        curr_resync;    /* last block scheduled */
         /* As resync requests can complete out of order, we cannot easily track
          * how much resync has been completed.  So we occasionally pause until