On Dec 8, 2019, at 6:23 PM, Theodore Ts'o <tytso@mit.edu> wrote:
> 
> This allows us to test various error handling code paths
> 
> Previous-Version-Link: https://lore.kernel.org/r/20191204032335.7683-2-tytso@mit.edu
> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
> ---
> 
> +
> +static inline bool ext4_simulate_fail(struct super_block *sb,
> +				     unsigned long code)
> +{
> +#ifdef CONFIG_EXT4_DEBUG
> +	struct ext4_sb_info *sbi = EXT4_SB(sb);
> +
> +	if (sbi->s_simulate_fail != code)

This should be marked unlikely(), as it is definitely one of the places
that is legitimately rarely true.  Sorry for not pointing this out on
the previous version of the patch.

Cheers, Andreas