[PATCH] md: fix up some rdev rcu locking in raid5/6

There is this "FIXME" comment with a typo in it!!  that been annoying me for
days, so I just had to remove it.

conf->disks[i].rdev should only be accessed if
  - we know we hold a reference or
  - the mddev->reconfig_sem is down or
  - we have a rcu_readlock

handle_stripe was referencing rdev in three places without any of these.  For
the first two, get an rcu_readlock.  For the last, the same access
(md_sync_acct call) is made a little later after the rdev has been claimed
under and rcu_readlock, if R5_Syncio is set.  So just use that access...
However R5_Syncio isn't really needed as the 'syncing' variable contains the
same information.  So use that instead.

Issues, comment, and fix are identical in raid5 and raid6.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 0 insertions, 1 deletions

diff --git a/include/linux/raid/raid5.h b/include/linux/raid/raid5.h
index e9c1c0d4f90b..28fcd7533ac4 100644
--- a/include/linux/raid/raid5.h
+++ b/include/linux/raid/raid5.h
@@ -152,7 +152,6 @@ struct stripe_head {
 #define R5_Insync       3       /* rdev && rdev->in_sync at start */
 #define R5_Wantread     4       /* want to schedule a read */
 #define R5_Wantwrite    5
-#define R5_Syncio       6       /* this io need to be accounted as resync io */
 #define R5_Overlap      7       /* There is a pending overlapping request on this block */
 #define R5_ReadError    8       /* seen a read error here recently */
 #define R5_ReWrite      9       /* have tried to over-write the readerror */