NFSv4: Turn off open-by-filehandle and NFS re-export for NFSv4.0

[ Upstream commit 2a9d683b48c8a87e61a4215792d44c90bcbbb536 ]

The NFSv4.0 protocol only supports open() by name. It cannot therefore
be used with open_by_handle() and friends, nor can it be re-exported by
knfsd.

Reported-by: Chuck Lever III <chuck.lever@oracle.com>
Fixes: 20fa19027286 ("nfs: add export operations")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index e65c83494c052758cf6e321647a2ee54ca0b8256..a847011f36c965f38e3fe9fbe700e1f9211997b9 100644 (file)
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1046,22 +1046,31 @@ static void nfs_fill_super(struct super_block *sb, struct nfs_fs_context *ctx)
        if (ctx->bsize)
                sb->s_blocksize = nfs_block_size(ctx->bsize, &sb->s_blocksize_bits);
 
-       if (server->nfs_client->rpc_ops->version != 2) {
-               /* The VFS shouldn't apply the umask to mode bits. We will do
-                * so ourselves when necessary.
+       switch (server->nfs_client->rpc_ops->version) {
+       case 2:
+               sb->s_time_gran = 1000;
+               sb->s_time_min = 0;
+               sb->s_time_max = U32_MAX;
+               break;
+       case 3:
+               /*
+                * The VFS shouldn't apply the umask to mode bits.
+                * We will do so ourselves when necessary.
                 */
                sb->s_flags |= SB_POSIXACL;
                sb->s_time_gran = 1;
-               sb->s_export_op = &nfs_export_ops;
-       } else
-               sb->s_time_gran = 1000;
-
-       if (server->nfs_client->rpc_ops->version != 4) {
                sb->s_time_min = 0;
                sb->s_time_max = U32_MAX;
-       } else {
+               sb->s_export_op = &nfs_export_ops;
+               break;
+       case 4:
+               sb->s_flags |= SB_POSIXACL;
+               sb->s_time_gran = 1;
                sb->s_time_min = S64_MIN;
                sb->s_time_max = S64_MAX;
+               if (server->caps & NFS_CAP_ATOMIC_OPEN_V1)
+                       sb->s_export_op = &nfs_export_ops;
+               break;
        }
 
        sb->s_magic = NFS_SUPER_MAGIC;