[PATCH 3/3] NFSD: Tighten header includes in localio.c

[Chuck Lever <cel@kernel.org>]

As a prerequisite to converting NFSD to use xdrgen more broadly,
NFSD source files should not depend on NFS client headers.
fs/nfsd/localio.c is server-side LOCALIO code, yet it pulled in
three of them: <linux/nfs_fs.h>, the client inode header (struct
nfs_inode, NFS_I(), writeback helpers), which server code never
uses; <linux/nfs_xdr.h>, whose only referenced symbol is
decode_opaque_fixed(), a static inline that exists to remap the
error return to -EIO for client call sites; and the catch-all
<linux/nfs.h>.

Convert the UUID decoder to call the canonical SUNRPC primitive
xdr_stream_decode_opaque_fixed() directly. It is shared by client
and server, performs the identical bounds check, and is already
reachable through <linux/sunrpc/clnt.h>. With the wrapper gone,
localio.c references no symbol from <linux/nfs_xdr.h>, and with
that header gone, none of the NFSv3 definitions its structs embed
are needed here.

Drop all three client includes and add what the file actually
uses: struct nfs_fh comes from <linux/nfs_fh.h>, included directly
rather than through nfslocalio.h's conditional re-export, and
NFS4_FHSIZE from <linux/nfs4.h>. enum nfs_stat and
nfs_stat_to_errno continue to come from the already-included
<linux/nfs_common.h>.

Signed-off-by: Chuck Lever <cel@kernel.org>
---
 fs/nfsd/localio.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/fs/nfsd/localio.c b/fs/nfsd/localio.c
index c458c01e9478..4110be02b750 100644
--- a/fs/nfsd/localio.c
+++ b/fs/nfsd/localio.c
@@ -11,11 +11,10 @@
 #include <linux/exportfs.h>
 #include <linux/sunrpc/svcauth.h>
 #include <linux/sunrpc/clnt.h>
-#include <linux/nfs.h>
+#include <linux/nfs4.h>
 #include <linux/nfs_common.h>
+#include <linux/nfs_fh.h>
 #include <linux/nfslocalio.h>
-#include <linux/nfs_fs.h>
-#include <linux/nfs_xdr.h>
 #include <linux/string.h>
 
 #include "nfsd.h"
@@ -179,7 +178,7 @@ static bool localio_decode_uuidarg(struct svc_rqst *rqstp,
 	struct localio_uuidarg *argp = rqstp->rq_argp;
 	u8 uuid[UUID_SIZE];
 
-	if (decode_opaque_fixed(xdr, uuid, UUID_SIZE))
+	if (xdr_stream_decode_opaque_fixed(xdr, uuid, UUID_SIZE) < 0)
 		return false;
 	import_uuid(&argp->uuid, uuid);
 
-- 
2.54.0