[PATCH] md: support write-mostly device in raid1
This allows a device in a raid1 to be marked as "write mostly". Read requests
will only be sent if there is no other option.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index 817062b..7ef78e1 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -181,6 +181,9 @@
int faulty; /* if faulty do not issue IO requests */
int in_sync; /* device is a full member of the array */
+ unsigned long flags; /* Should include faulty and in_sync here. */
+#define WriteMostly 4 /* Avoid reading if at all possible */
+
int desc_nr; /* descriptor index in the superblock */
int raid_disk; /* role of device in array */
int saved_raid_disk; /* role that device used to have in the