[PATCH 5.19 07/38] NFSv4: Turn off open-by-filehandle and NFS re-export for NFSv4.0

Greg Kroah-Hartman
2022-09-21T15:48:06Z

From: Trond Myklebust <trond.myklebust@hammerspace.com>

[ 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>
---
fs/nfs/super.c | 27 ++++++++++++++++++---------
1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 6ab5eeb000dc..5e4bacb77bfc 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1051,22 +1051,31 @@ 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;
--
2.35.1