dm snapshot: remove stale FIXME in snapshot_map()

Commit ae1093be ("dm snapshot: use mutex instead of rw_semaphore")
eliminated the need to worry about read vs write locking.  So remove a
FIXME in snapshot_map() that is concerned about selectively taking a
write lock.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 6f72ac7bbf9a9958522e45219dca4322cd983816..ae4b33d109246e305c73f8231d122ce5b5cfdb41 100644 (file)
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1707,8 +1707,6 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio)
        if (!s->valid)
                return DM_MAPIO_KILL;
 
-       /* FIXME: should only take write lock if we need
-        * to copy an exception */
        mutex_lock(&s->lock);
 
        if (!s->valid || (unlikely(s->snapshot_overflowed) &&