Re: [PATCH 2/2] mke2fs: Enable lazy_itable_init on newer kernel by default

[Eric Sandeen <sandeen@redhat.com>]

On 2/24/14, 11:41 AM, Lukas Czerner wrote:
> Currently is used did not specified lazy_itable_init option we rely on

s/is used did not specified/if user did not specify/ :)

> information from ext4 module exported via sysfs interface. However if
> the ext4 module is not loaded it will not be enabled even though kernel
> might support it.
> 
> With this commit we set the default according to the kernel version,
> however we still allow it to be set manually via extended option or be
> enabled in case that ext4 module advertise that it supports this
> feature.
> 
> Signed-off-by: Lukas Czerner <lczerner@redhat.com>

Thanks,
Reviewed-by: Eric Sandeen <sandeen@redhat.com>

> ---
>  misc/mke2fs.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/misc/mke2fs.c b/misc/mke2fs.c
> index 957b4b6..e1c6d09 100644
> --- a/misc/mke2fs.c
> +++ b/misc/mke2fs.c
> @@ -2146,7 +2146,15 @@ profile_error:
>  			blocksize, sys_page_size);
>  	}
>  
> -	lazy_itable_init = 0;
> +	/*
> +	 * On newer kernels we do have lazy_itable_init support. So pick the
> +	 * right default in case ext4 module is not loaded.
> +	 */
> +	if (is_before_linux_ver(2, 6, 37))
> +		lazy_itable_init = 0;
> +	else
> +		lazy_itable_init = 1;
> +
>  	if (access("/sys/fs/ext4/features/lazy_itable_init", R_OK) == 0)
>  		lazy_itable_init = 1;
>  
>