[PATCH] md: teach raid5 the difference between 'check' and 'repair'.

With this, raid5 can be asked to check parity without repairing it.  It also
keeps a count of the number of incorrect parity blocks found (mismatches) and
reports them through sysfs.

Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index efd04dca0abd..cb8b44d1588b 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -175,6 +175,10 @@ struct mddev_s
         sector_t                        resync_mark_cnt;/* blocks written at resync_mark */
 
         sector_t                        resync_max_sectors; /* may be set by personality */
+
+        sector_t                        resync_mismatches; /* count of sectors where
+                                                            * parity/replica mismatch found
+                                                            */
         /* recovery/resync flags 
          * NEEDED:   we might need to start a resync/recover
          * RUNNING:  a thread is running, or about to be started