[PATCH 2/7] fs: implement is_tftp_fs()

[Stefan Lengfeld]

Hi Sascha,

On Wed, Jan 24, 2018 at 08:45:29AM +0100, Sascha Hauer wrote:
> Some commands need files in which they can lseek backwards which
> is particularly not possible on TFTP. Instead of hiding this
> behind can_lseek_backward() create a function for it which tests
> if the file is on TFTP directly rather than using different
> lseek operations.
> 
> Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
> ---
>  fs/fs.c      | 22 ++++++++++++++++++++++
>  include/fs.h | 10 ++++++++++
>  2 files changed, 32 insertions(+)
> 
> diff --git a/fs/fs.c b/fs/fs.c
> index 6f15e93ba9..e073e3577d 100644
> --- a/fs/fs.c
> +++ b/fs/fs.c
> @@ -1906,3 +1906,25 @@ char *path_get_linux_rootarg(const char *path)
>  
>  	return xstrdup(str);
>  }
> +
> +/**
> + * __is_tftp_fs() - return true when path is mounted on TFTP
> + * @path: The path
> + *
> + * Do not use directly, use is_tftp_fs instead.
> + *
> + * Return: true when @path is on TFTP, false otherwise
> + */
> +bool __is_tftp_fs(const char *path)
> +{
> +	struct fs_device_d *fsdev;
> +
> +	fsdev = get_fsdevice_by_path(path);
> +	if (!fsdev)
> +		return false;
> +
> +	if (strcmp(fsdev->driver->drv.name, "tftp"))
> +		return false;
> +
> +	return true;
> +}
> diff --git a/include/fs.h b/include/fs.h
> index 3d88bfad4a..5a50d9b9e4 100644
> --- a/include/fs.h
> +++ b/include/fs.h
> @@ -121,6 +121,16 @@ static inline int can_lseek_backward(int fd)
>  	return 1;
>  }
>  
> +bool __is_tftp_fs(const char *path);
> +
> +static inline bool is_tftp_fs(const char *path)
> +{
> +	if (!IS_ENABLED(CONFIG_FS_TFTP))
> +		return 0;

Nitpick: Maybe use 'false' instead of '0', because return value is a
boolean.

Kind regards,
Stefan