The ioctl requires CAP_SYS_ADMIN, so sysfs should too.
Note that we don't require CAP_SYS_ADMIN for reading
attributes even though the ioctl does.  There is no reason
to limit the read access, and much of the information is
already available via /proc/mdstat

cc: Chris Wright <redacted>
Signed-off-by: Neil Brown <redacted>

### Diffstat output
 ./drivers/md/md.c |    4 ++++
 1 file changed, 4 insertions(+)

diff .prev/drivers/md/md.c ./drivers/md/md.c

--- .prev/drivers/md/md.c	2006-06-27 12:17:33.000000000 +1000
+++ ./drivers/md/md.c	2006-06-27 12:17:33.000000000 +1000

@@ -1928,6 +1928,8 @@ rdev_attr_store(struct kobject *kobj, st
 
 	if (!entry->store)
 		return -EIO;
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
 	return entry->store(rdev, page, length);
 }
 

@@ -2861,6 +2863,8 @@ md_attr_store(struct kobject *kobj, stru
 
 	if (!entry->store)
 		return -EIO;
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
 	rv = mddev_lock(mddev);
 	if (!rv) {
 		rv = entry->store(mddev, page, length);