Re: [PATCH] fs/dcache: use write lock in the fallback instead of read lock

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

> @@ -1692,7 +1692,7 @@ void shrink_dcache_for_umount(struct super_block *sb)
>  {
>  	struct dentry *dentry;
>  
> -	WARN(down_read_trylock(&sb->s_umount), "s_umount should've been locked");
> +	WARN(down_write_trylock(&sb->s_umount), "s_umount should've been locked");

This really should be a lockdep_assert_held_write() instead.