Re: [PATCH 1/1] NFSv4.2: Remove ifdef CONFIG_NFSD_V4 from nfsV4.2 client SSC code.

[Trond Myklebust <trondmy@hammerspace.com>]

On Tue, 2021-04-20 at 13:10 -0400, Dai Ngo wrote:
> The client SSC code should not depend on any of the CONFIG_NFSD config.
> Replaced CONFIG_NFSD_V4 with CONFIG_NFS_V4_2_SSC_HELPER in nfs4file.c
> and super.c. This patch also fixes the compiler warning of unused
> variables when NFS_V4_2 is configured and NFSD_V4 is not.
> 
> Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
> ---
>  fs/nfs/nfs4file.c | 6 ++++--
>  fs/nfs/super.c    | 6 +++---
>  2 files changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
> index 441a2fa073c8..042668f06adc 100644
> --- a/fs/nfs/nfs4file.c
> +++ b/fs/nfs/nfs4file.c
> @@ -313,6 +313,7 @@ static loff_t nfs42_remap_file_range(struct file
> *src_file, loff_t src_off,
>         return ret < 0 ? ret : count;
>  }
>  
> +#ifdef CONFIG_NFS_V4_2_SSC_HELPER
>  static int read_name_gen = 1;
>  #define SSC_READ_NAME_BODY "ssc_read_%d"
>  
> @@ -411,6 +412,7 @@ static const struct nfs4_ssc_client_ops
> nfs4_ssc_clnt_ops_tbl = {
>         .sco_open = __nfs42_ssc_open,
>         .sco_close = __nfs42_ssc_close,
>  };
> +#endif /* CONFIG_NFS_V4_2_SSC_HELPER */
>  
>  /**
>   * nfs42_ssc_register_ops - Wrapper to register NFS_V4 ops in
> nfs_common
> @@ -420,7 +422,7 @@ static const struct nfs4_ssc_client_ops
> nfs4_ssc_clnt_ops_tbl = {
>   */
>  void nfs42_ssc_register_ops(void)
>  {
> -#ifdef CONFIG_NFSD_V4
> +#ifdef CONFIG_NFS_V4_2_SSC_HELPER
>         nfs42_ssc_register(&nfs4_ssc_clnt_ops_tbl);
>  #endif
>  }
> @@ -433,7 +435,7 @@ void nfs42_ssc_register_ops(void)
>   */
>  void nfs42_ssc_unregister_ops(void)
>  {
> -#ifdef CONFIG_NFSD_V4
> +#ifdef CONFIG_NFS_V4_2_SSC_HELPER
>         nfs42_ssc_unregister(&nfs4_ssc_clnt_ops_tbl);
>  #endif
>  }
> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
> index 94885c6f8f54..df17e0ddbc4d 100644
> --- a/fs/nfs/super.c
> +++ b/fs/nfs/super.c
> @@ -86,7 +86,7 @@ const struct super_operations nfs_sops = {
>  };
>  EXPORT_SYMBOL_GPL(nfs_sops);
>  
> -#ifdef CONFIG_NFS_V4_2
> +#ifdef CONFIG_NFS_V4_2_SSC_HELPER
>  static const struct nfs_ssc_client_ops nfs_ssc_clnt_ops_tbl = {
>         .sco_sb_deactive = nfs_sb_deactive,
>  };
> @@ -116,14 +116,14 @@ static void unregister_nfs4_fs(void)
>  #ifdef CONFIG_NFS_V4_2
>  static void nfs_ssc_register_ops(void)
>  {
> -#ifdef CONFIG_NFSD_V4
> +#ifdef CONFIG_NFS_V4_2_SSC_HELPER
>         nfs_ssc_register(&nfs_ssc_clnt_ops_tbl);
>  #endif
>  }
>  
>  static void nfs_ssc_unregister_ops(void)
>  {
> -#ifdef CONFIG_NFSD_V4
> +#ifdef CONFIG_NFS_V4_2_SSC_HELPER
>         nfs_ssc_unregister(&nfs_ssc_clnt_ops_tbl);
>  #endif
>  }


OK. This looks better, and gives us a more direct dependency.
However looking independently at fs/Kconfig, I'm seeing

config NFS_V4_2_SSC_HELPER
        tristate
        default y if NFS_V4=y || NFS_FS=y

Shouldn't that rather be:

config NFS_V4_2_SSC_HELPER
	bool
	default y if NFS_V4_2 || NFSD_V4_2_INTER_SSC

...to allow us to get rid of these CONFIG_NFS_V4_2_SSC_HELPER #ifdefs
in fs/nfs? I suspect the above would also allow us to simplify the
dependencies in fs/nfsd/Kconfig for NFSD_V4_2_INTER_SSC too.

-- 
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@hammerspace.com