waitqueue_active should be preceded by a barrier, in this function we don't need to call it all the time.
Signed-off-by: David Sterba <[email protected]> --- fs/btrfs/transaction.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 74bc3338418b..e8e5b5a10719 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -82,6 +82,12 @@ void btrfs_put_transaction(struct btrfs_transaction *transaction) static void clear_btree_io_tree(struct extent_io_tree *tree) { spin_lock(&tree->lock); + /* + * Do a single barrier for the waitqueue_active check here, the state + * of the waitqueue should not change once clear_btree_io_tree is + * called. + */ + smp_mb(); while (!RB_EMPTY_ROOT(&tree->state)) { struct rb_node *node; struct extent_state *state; -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
