Btrfs: barrier before waitqueue_active

[linux-2.6-block.git] / fs / btrfs / disk-io.c

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index a7ad8fc8dc53e02c3c966a0eaa3881ff99c01641..dd86a5d884280458a1dd89299fc682cb6ad69bd3 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -754,9 +754,7 @@ static void run_one_async_done(struct btrfs_work *work)
        limit = btrfs_async_submit_limit(fs_info);
        limit = limit * 2 / 3;
 
-       atomic_dec(&fs_info->nr_async_submits);
-
-       if (atomic_read(&fs_info->nr_async_submits) < limit &&
+       if (atomic_dec_return(&fs_info->nr_async_submits) < limit &&
            waitqueue_active(&fs_info->async_submit_wait))
                wake_up(&fs_info->async_submit_wait);
 
@@ -3783,14 +3781,17 @@ int btrfs_cleanup_transaction(struct btrfs_root *root)
                /* FIXME: cleanup wait for commit */
                t->in_commit = 1;
                t->blocked = 1;
+               smp_mb();
                if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
                        wake_up(&root->fs_info->transaction_blocked_wait);
 
                t->blocked = 0;
+               smp_mb();
                if (waitqueue_active(&root->fs_info->transaction_wait))
                        wake_up(&root->fs_info->transaction_wait);
 
                t->commit_done = 1;
+               smp_mb();
                if (waitqueue_active(&t->commit_wait))
                        wake_up(&t->commit_wait);