Re: [PATCH bpf-next 1/4] libbpf: Define DEFAULT_BPFFS

[Daniel Borkmann <daniel@iogearbox.net>]

On 4/23/22 4:00 PM, Yafang Shao wrote:
> Let's use a macro DEFAULT_BPFFS instead of the hard-coded "/sys/fs/bpf".
> 
> Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
[...]
> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> index cdbfee60ea3e..3784867811a4 100644
> --- a/tools/lib/bpf/libbpf.h
> +++ b/tools/lib/bpf/libbpf.h
> @@ -28,6 +28,8 @@ LIBBPF_API __u32 libbpf_major_version(void);
>   LIBBPF_API __u32 libbpf_minor_version(void);
>   LIBBPF_API const char *libbpf_version_string(void);
>   
> +#define DEFAULT_BPFFS "/sys/fs/bpf"

Small nit, but given this is included in a lot of places potentially, it should
have a LIBBPF_ prefix to avoid collisions. Maybe: LIBBPF_BPFFS_DEFAULT_MNT

>   enum libbpf_errno {
>   	__LIBBPF_ERRNO__START = 4000,
>   
> @@ -91,7 +93,7 @@ struct bpf_object_open_opts {
>   	bool relaxed_core_relocs;
>   	/* maps that set the 'pinning' attribute in their definition will have
>   	 * their pin_path attribute set to a file in this directory, and be
> -	 * auto-pinned to that path on load; defaults to "/sys/fs/bpf".
> +	 * auto-pinned to that path on load; defaults to DEFAULT_BPFFS.
>   	 */
>   	const char *pin_root_path;
>   
> @@ -190,7 +192,7 @@ bpf_object__open_xattr(struct bpf_object_open_attr *attr);
>   
>   enum libbpf_pin_type {
>   	LIBBPF_PIN_NONE,
> -	/* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */
> +	/* PIN_BY_NAME: pin maps by name (in DEFAULT_BPFFS by default) */
>   	LIBBPF_PIN_BY_NAME,
>   };
>   
>