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Date:   Thu, 1 Apr 2021 11:53:29 +0800
From:   Eryu Guan <eguan@linux.alibaba.com>
To:     trondmy@kernel.org
Cc:     linux-nfs@vger.kernel.org, Olga Kornievskaia <aglo@umich.edu>
Subject: Re: [PATCH] NFS: Fix up the support for
 CONFIG_NFS_DISABLE_UDP_SUPPORT
Message-ID: <20210401035329.GR95214@e18g06458.et15sqa>
References: <20210330134010.61313-1-trondmy@kernel.org>
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In-Reply-To: <20210330134010.61313-1-trondmy@kernel.org>
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On Tue, Mar 30, 2021 at 09:40:10AM -0400, trondmy@kernel.org wrote:
> From: Trond Myklebust <trond.myklebust@hammerspace.com>
> 
> Rather than removing the support in nfs_init_timeout_values(), we should
> just fix up the validation checks in the mount option parsers.
> 
> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Add a 'Fixes' tag? i.e.

Fixes: b24ee6c64ca7 ("NFS: allow deprecation of NFS UDP protocol")

Thanks,
Eryu

> ---
>  fs/nfs/client.c     |  2 --
>  fs/nfs/fs_context.c | 54 +++++++++++++++++++++++++++++----------------
>  2 files changed, 35 insertions(+), 21 deletions(-)
> 
> diff --git a/fs/nfs/client.c b/fs/nfs/client.c
> index 94d47be1d1f6..2aeb4e52a4f1 100644
> --- a/fs/nfs/client.c
> +++ b/fs/nfs/client.c
> @@ -476,7 +476,6 @@ void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
>  			to->to_maxval = to->to_initval;
>  		to->to_exponential = 0;
>  		break;
> -#ifndef CONFIG_NFS_DISABLE_UDP_SUPPORT
>  	case XPRT_TRANSPORT_UDP:
>  		if (retrans == NFS_UNSPEC_RETRANS)
>  			to->to_retries = NFS_DEF_UDP_RETRANS;
> @@ -487,7 +486,6 @@ void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
>  		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
>  		to->to_exponential = 1;
>  		break;
> -#endif
>  	default:
>  		BUG();
>  	}
> diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
> index 902db1262d2b..cdf32b9a6c35 100644
> --- a/fs/nfs/fs_context.c
> +++ b/fs/nfs/fs_context.c
> @@ -283,20 +283,40 @@ static int nfs_verify_server_address(struct sockaddr *addr)
>  	return 0;
>  }
>  
> +#ifdef CONFIG_NFS_DISABLE_UDP_SUPPORT
> +static bool nfs_server_transport_udp_invalid(const struct nfs_fs_context *ctx)
> +{
> +	return true;
> +}
> +#else
> +static bool nfs_server_transport_udp_invalid(const struct nfs_fs_context *ctx)
> +{
> +	if (ctx->version == 4)
> +		return true;
> +	return false;
> +}
> +#endif
> +
>  /*
>   * Sanity check the NFS transport protocol.
> - *
>   */
> -static void nfs_validate_transport_protocol(struct nfs_fs_context *ctx)
> +static int nfs_validate_transport_protocol(struct fs_context *fc,
> +					   struct nfs_fs_context *ctx)
>  {
>  	switch (ctx->nfs_server.protocol) {
>  	case XPRT_TRANSPORT_UDP:
> +		if (nfs_server_transport_udp_invalid(ctx))
> +			goto out_invalid_transport_udp;
> +		break;
>  	case XPRT_TRANSPORT_TCP:
>  	case XPRT_TRANSPORT_RDMA:
>  		break;
>  	default:
>  		ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
>  	}
> +	return 0;
> +out_invalid_transport_udp:
> +	return nfs_invalf(fc, "NFS: Unsupported transport protocol udp");
>  }
>  
>  /*
> @@ -305,8 +325,6 @@ static void nfs_validate_transport_protocol(struct nfs_fs_context *ctx)
>   */
>  static void nfs_set_mount_transport_protocol(struct nfs_fs_context *ctx)
>  {
> -	nfs_validate_transport_protocol(ctx);
> -
>  	if (ctx->mount_server.protocol == XPRT_TRANSPORT_UDP ||
>  	    ctx->mount_server.protocol == XPRT_TRANSPORT_TCP)
>  			return;
> @@ -929,6 +947,7 @@ static int nfs23_parse_monolithic(struct fs_context *fc,
>  	struct nfs_fh *mntfh = ctx->mntfh;
>  	struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
>  	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
> +	int ret;
>  
>  	if (data == NULL)
>  		goto out_no_data;
> @@ -1054,6 +1073,10 @@ static int nfs23_parse_monolithic(struct fs_context *fc,
>  		goto generic;
>  	}
>  
> +	ret = nfs_validate_transport_protocol(fc, ctx);
> +	if (ret)
> +		return ret;
> +
>  	ctx->skip_reconfig_option_check = true;
>  	return 0;
>  
> @@ -1155,6 +1178,7 @@ static int nfs4_parse_monolithic(struct fs_context *fc,
>  {
>  	struct nfs_fs_context *ctx = nfs_fc2context(fc);
>  	struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
> +	int ret;
>  	char *c;
>  
>  	if (!data) {
> @@ -1227,9 +1251,9 @@ static int nfs4_parse_monolithic(struct fs_context *fc,
>  	ctx->acdirmin	= data->acdirmin;
>  	ctx->acdirmax	= data->acdirmax;
>  	ctx->nfs_server.protocol = data->proto;
> -	nfs_validate_transport_protocol(ctx);
> -	if (ctx->nfs_server.protocol == XPRT_TRANSPORT_UDP)
> -		goto out_invalid_transport_udp;
> +	ret = nfs_validate_transport_protocol(fc, ctx);
> +	if (ret)
> +		return ret;
>  done:
>  	ctx->skip_reconfig_option_check = true;
>  	return 0;
> @@ -1240,9 +1264,6 @@ static int nfs4_parse_monolithic(struct fs_context *fc,
>  
>  out_no_address:
>  	return nfs_invalf(fc, "NFS4: mount program didn't pass remote address");
> -
> -out_invalid_transport_udp:
> -	return nfs_invalf(fc, "NFS: Unsupported transport protocol udp");
>  }
>  #endif
>  
> @@ -1307,6 +1328,10 @@ static int nfs_fs_context_validate(struct fs_context *fc)
>  	if (!nfs_verify_server_address(sap))
>  		goto out_no_address;
>  
> +	ret = nfs_validate_transport_protocol(fc, ctx);
> +	if (ret)
> +		return ret;
> +
>  	if (ctx->version == 4) {
>  		if (IS_ENABLED(CONFIG_NFS_V4)) {
>  			if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
> @@ -1315,9 +1340,6 @@ static int nfs_fs_context_validate(struct fs_context *fc)
>  				port = NFS_PORT;
>  			max_namelen = NFS4_MAXNAMLEN;
>  			max_pathlen = NFS4_MAXPATHLEN;
> -			nfs_validate_transport_protocol(ctx);
> -			if (ctx->nfs_server.protocol == XPRT_TRANSPORT_UDP)
> -				goto out_invalid_transport_udp;
>  			ctx->flags &= ~(NFS_MOUNT_NONLM | NFS_MOUNT_NOACL |
>  					NFS_MOUNT_VER3 | NFS_MOUNT_LOCAL_FLOCK |
>  					NFS_MOUNT_LOCAL_FCNTL);
> @@ -1326,10 +1348,6 @@ static int nfs_fs_context_validate(struct fs_context *fc)
>  		}
>  	} else {
>  		nfs_set_mount_transport_protocol(ctx);
> -#ifdef CONFIG_NFS_DISABLE_UDP_SUPPORT
> -	       if (ctx->nfs_server.protocol == XPRT_TRANSPORT_UDP)
> -		       goto out_invalid_transport_udp;
> -#endif
>  		if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
>  			port = NFS_RDMA_PORT;
>  	}
> @@ -1363,8 +1381,6 @@ static int nfs_fs_context_validate(struct fs_context *fc)
>  out_v4_not_compiled:
>  	nfs_errorf(fc, "NFS: NFSv4 is not compiled into kernel");
>  	return -EPROTONOSUPPORT;
> -out_invalid_transport_udp:
> -	return nfs_invalf(fc, "NFS: Unsupported transport protocol udp");
>  out_no_address:
>  	return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
>  out_mountproto_mismatch:
> -- 
> 2.30.2