[PATCH] md: expose device slot information via sysfs
This the role that a device has in an array can be viewed and set.
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/Documentation/md.txt b/Documentation/md.txt
index 69f742d..d525fff 100644
--- a/Documentation/md.txt
+++ b/Documentation/md.txt
@@ -236,6 +236,14 @@
providing an ongoing count for arrays with metadata managed by
userspace.
+ slot
+ This gives the role that the device has in the array. It will
+ either be 'none' if the device is not active in the array
+ (i.e. is a spare or has failed) or an integer less than the
+ 'raid_disks' number for the array indicating which possition
+ it currently fills. This can only be set while assembling an
+ array. A device for which this is set is assumed to be working.
+
An active md device will also contain and entry for each active device
in the array. These are named