[PATCH v3 20/34] NFSD: Use xdrgen XDR functions for the NFSv3 RMDIR procedure

[PATCH v3 20/34] NFSD: Use xdrgen XDR functions for the NFSv3 RMDIR procedure

[Chuck Lever]

Replace the NFSPROC3_RMDIR entry in the nfsd_procedures3 array
with an entry that dispatches the xdrgen-generated
nfs_svc_decode_RMDIR3args and nfs_svc_encode_RMDIR3res. A
wrapper structure bridges the generated xdrgen argument type and
the legacy svc_fh representation the NFSD VFS layer still uses;
the result uses the generated RMDIR3res type directly.

Filename validity is now checked by nfsd3_proc_rmdir() so that a
proper NFS3ERR status code can be returned to the client rather
than GARBAGE_ARGS.

The pc_argzero field is now set to zero for the NFSv3 RMDIR
procedure. The xdrgen decoders are trusted to initialize all
arguments in the argp->xdrgen field, making the early defensive
memset unnecessary. The remaining argp fields are cleared as
needed.

Because nfsd3_proc_rmdir() now assembles the WCC data, that work
moves out of the XDR result encoder, and the reference to the
file handle can be released directly by nfsd3_proc_rmdir(). A
separate ->pc_release callback is thus no longer needed. This
makes it straightforward to confirm that the file handle is
properly released during every error flow.

nfs3svc_decode_diropargs() and nfs3svc_encode_wccstat() no longer
have any callers, so they are removed.

Signed-off-by: Chuck Lever <cel@kernel.org>
---
 fs/nfsd/nfs3proc.c | 74 ++++++++++++++++++++++++++++++++--------------
 fs/nfsd/nfs3xdr.c  | 18 -----------
 fs/nfsd/xdr3.h     |  8 -----
 3 files changed, 51 insertions(+), 49 deletions(-)

diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index 540e4a6a42e0..db33866273fa 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -170,6 +170,13 @@ struct REMOVE3args_wrapper {
 
 static_assert(offsetof(struct REMOVE3args_wrapper, xdrgen) == 0);
 
+struct RMDIR3args_wrapper {
+	struct RMDIR3args	xdrgen;
+	struct svc_fh		fh;
+};
+
+static_assert(offsetof(struct RMDIR3args_wrapper, xdrgen) == 0);
+
 static int nfsd3_ftype3_to_mode(ftype3 ftype)
 {
 	switch (ftype) {
@@ -1298,19 +1305,42 @@ static __be32 nfsd3_proc_remove(struct svc_rqst *rqstp)
 	return rpc_success;
 }
 
-/*
- * Remove a directory
+/**
+ * nfsd3_proc_rmdir - RMDIR: Remove a directory
+ * @rqstp: RPC transaction context
+ *
+ * Return:
+ *   %rpc_success:		RPC executed successfully
+ *
+ * RPC synopsis:
+ *   RMDIR3res NFSPROC3_RMDIR(RMDIR3args) = 13;
  */
-static __be32
-nfsd3_proc_rmdir(struct svc_rqst *rqstp)
+static __be32 nfsd3_proc_rmdir(struct svc_rqst *rqstp)
 {
-	struct nfsd3_diropargs *argp = rqstp->rq_argp;
-	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+	struct RMDIR3args_wrapper *argp = rqstp->rq_argp;
+	struct diropargs3 *object = &argp->xdrgen.object;
+	struct RMDIR3res *resp = rqstp->rq_resp;
+	struct svc_fh *fhp = &argp->fh;
 
-	fh_copy(&resp->fh, &argp->fh);
-	resp->status = nfsd_unlink(rqstp, &resp->fh, S_IFDIR,
-				   argp->name, argp->len);
-	resp->status = nfsd3_map_status(resp->status);
+	nfsd3_fh3_to_svc_fh(fhp, &object->dir);
+	resp->status = nfsd3_check_filename(object->name.data,
+					    object->name.len);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = nfsd_unlink(rqstp, fhp, S_IFDIR,
+				   (char *)object->name.data,
+				   object->name.len);
+
+out:
+	if (resp->status == nfs_ok) {
+		nfsd3_fill_wcc_data(rqstp, &resp->u.resok.dir_wcc, fhp);
+	} else {
+		resp->status = nfsd3_map_status(resp->status);
+		nfsd3_fill_wcc_data(rqstp, &resp->u.resfail.dir_wcc, fhp);
+	}
+
+	fh_put(fhp);
 	return rpc_success;
 }
 
@@ -1594,10 +1624,8 @@ nfsd3_proc_commit(struct svc_rqst *rqstp)
  * NFSv3 Server procedures.
  * Only the results of non-idempotent operations are cached.
  */
-#define nfs3svc_encode_wccstatres	nfs3svc_encode_wccstat
 #define nfsd3_readdirplusargs		nfsd3_readdirargs
 #define nfsd3_fhandleargs		nfsd_fhandle
-#define nfsd3_wccstatres		nfsd3_attrstat
 
 #define ST 1		/* status*/
 #define AT 21		/* attributes */
@@ -1752,16 +1780,15 @@ static const struct svc_procedure nfsd_procedures3[22] = {
 		.pc_name	= "REMOVE",
 	},
 	[NFSPROC3_RMDIR] = {
-		.pc_func = nfsd3_proc_rmdir,
-		.pc_decode = nfs3svc_decode_diropargs,
-		.pc_encode = nfs3svc_encode_wccstatres,
-		.pc_release = nfs3svc_release_fhandle,
-		.pc_argsize = sizeof(struct nfsd3_diropargs),
-		.pc_argzero = sizeof(struct nfsd3_diropargs),
-		.pc_ressize = sizeof(struct nfsd3_wccstatres),
-		.pc_cachetype = RC_REPLBUFF,
-		.pc_xdrressize = ST+WC,
-		.pc_name = "RMDIR",
+		.pc_func	= nfsd3_proc_rmdir,
+		.pc_decode	= nfs_svc_decode_RMDIR3args,
+		.pc_encode	= nfs_svc_encode_RMDIR3res,
+		.pc_argsize	= sizeof(struct RMDIR3args_wrapper),
+		.pc_argzero	= 0,
+		.pc_ressize	= sizeof(struct RMDIR3res),
+		.pc_cachetype	= RC_REPLBUFF,
+		.pc_xdrressize	= NFS3_RMDIR3res_sz,
+		.pc_name	= "RMDIR",
 	},
 	[NFSPROC3_RENAME] = {
 		.pc_func = nfsd3_proc_rename,
@@ -1870,7 +1897,6 @@ union nfsd3_xdrstore {
 	struct ACCESS3res		accessres;
 	struct READLINK3args_wrapper	readlinkargs;
 	struct READ3args_wrapper	readargs;
-	struct nfsd3_diropargs		diropargs;
 	struct WRITE3args_wrapper	writeargs;
 	struct CREATE3args_wrapper	createargs;
 	struct CREATE3res_wrapper	createres;
@@ -1882,6 +1908,8 @@ union nfsd3_xdrstore {
 	struct MKNOD3res_wrapper	mknodres;
 	struct REMOVE3args_wrapper	removeargs;
 	struct REMOVE3res		removeres;
+	struct RMDIR3args_wrapper	rmdirargs;
+	struct RMDIR3res		rmdirres;
 	struct nfsd3_renameargs		renameargs;
 	struct nfsd3_linkargs		linkargs;
 	struct nfsd3_readdirargs	readdirargs;
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index 53a82af80ad5..1cfc79724450 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -360,14 +360,6 @@ nfs3svc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 	return svcxdr_decode_nfs_fh3(xdr, &args->fh);
 }
 
-bool
-nfs3svc_decode_diropargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
-{
-	struct nfsd3_diropargs *args = rqstp->rq_argp;
-
-	return svcxdr_decode_diropargs3(xdr, &args->fh, &args->name, &args->len);
-}
-
 bool
 nfs3svc_decode_renameargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 {
@@ -448,16 +440,6 @@ nfs3svc_decode_commitargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
  * XDR encode functions
  */
 
-/* SETATTR, REMOVE, RMDIR */
-bool
-nfs3svc_encode_wccstat(struct svc_rqst *rqstp, struct xdr_stream *xdr)
-{
-	struct nfsd3_attrstat *resp = rqstp->rq_resp;
-
-	return svcxdr_encode_nfsstat3(xdr, resp->status) &&
-		svcxdr_encode_wcc_data(rqstp, xdr, &resp->fh);
-}
-
 /* RENAME */
 bool
 nfs3svc_encode_renameres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h
index 6d5cea6baf3a..fac60fb4cdf9 100644
--- a/fs/nfsd/xdr3.h
+++ b/fs/nfsd/xdr3.h
@@ -19,12 +19,6 @@
 #define NFS3_MAXNAMLEN			NAME_MAX
 #define NFS3_MAXPATHLEN			PATH_MAX
 
-struct nfsd3_diropargs {
-	struct svc_fh		fh;
-	char *			name;
-	unsigned int		len;
-};
-
 struct nfsd3_accessargs {
 	struct svc_fh		fh;
 	__u32			access;
@@ -171,14 +165,12 @@ struct nfsd3_fhandle_pair {
 };
 
 bool nfs3svc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
-bool nfs3svc_decode_diropargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_renameargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_commitargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 
-bool nfs3svc_encode_wccstat(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_accessres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_renameres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_linkres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
-- 
2.55.0

[PATCH v3 21/34] NFSD: Use xdrgen XDR functions for the NFSv3 RENAME procedure

[Chuck Lever]

Replace the NFSPROC3_RENAME entry in the nfsd_procedures3 array
with an entry that dispatches the xdrgen-generated
nfs_svc_decode_RENAME3args and nfs_svc_encode_RENAME3res. A
wrapper structure bridges the generated xdrgen argument type and
the legacy svc_fh representation the NFSD VFS layer still uses;
the result uses the generated RENAME3res type directly.

Filename validity is now checked by nfsd3_proc_rename() so that a
proper NFS3ERR status code can be returned to the client rather
than GARBAGE_ARGS.

The pc_argzero field is now set to zero for the NFSv3 RENAME
procedure. The xdrgen decoders are trusted to initialize all
arguments in the argp->xdrgen field, making the early defensive
memset unnecessary. The remaining argp fields are cleared as
needed.

Because nfsd3_proc_rename() now assembles the WCC data, that work
moves out of the XDR result encoder, and the references to the
file handles can be released directly by nfsd3_proc_rename(). A
separate ->pc_release callback is thus no longer needed. This
makes it straightforward to confirm that the file handles are
properly released during every error flow.

nfs3svc_decode_renameargs() and nfs3svc_encode_renameres() no
longer have any callers, so they are removed.

Signed-off-by: Chuck Lever <cel@kernel.org>
---
 fs/nfsd/nfs3proc.c | 89 +++++++++++++++++++++++++++++++++++-----------
 fs/nfsd/nfs3xdr.c  | 22 ------------
 fs/nfsd/xdr3.h     | 17 ---------
 3 files changed, 68 insertions(+), 60 deletions(-)

diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index db33866273fa..7fd968fdb145 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -177,6 +177,14 @@ struct RMDIR3args_wrapper {
 
 static_assert(offsetof(struct RMDIR3args_wrapper, xdrgen) == 0);
 
+struct RENAME3args_wrapper {
+	struct RENAME3args	xdrgen;
+	struct svc_fh		ffh;
+	struct svc_fh		tfh;
+};
+
+static_assert(offsetof(struct RENAME3args_wrapper, xdrgen) == 0);
+
 static int nfsd3_ftype3_to_mode(ftype3 ftype)
 {
 	switch (ftype) {
@@ -1344,17 +1352,57 @@ static __be32 nfsd3_proc_rmdir(struct svc_rqst *rqstp)
 	return rpc_success;
 }
 
-static __be32
-nfsd3_proc_rename(struct svc_rqst *rqstp)
+/**
+ * nfsd3_proc_rename - RENAME: Rename a file or directory
+ * @rqstp: RPC transaction context
+ *
+ * Return:
+ *   %rpc_success:		RPC executed successfully
+ *
+ * RPC synopsis:
+ *   RENAME3res NFSPROC3_RENAME(RENAME3args) = 14;
+ */
+static __be32 nfsd3_proc_rename(struct svc_rqst *rqstp)
 {
-	struct nfsd3_renameargs *argp = rqstp->rq_argp;
-	struct nfsd3_renameres *resp = rqstp->rq_resp;
+	struct RENAME3args_wrapper *argp = rqstp->rq_argp;
+	struct diropargs3 *from = &argp->xdrgen.from;
+	struct diropargs3 *to = &argp->xdrgen.to;
+	struct RENAME3res *resp = rqstp->rq_resp;
+	struct svc_fh *ffhp = &argp->ffh;
+	struct svc_fh *tfhp = &argp->tfh;
 
-	fh_copy(&resp->ffh, &argp->ffh);
-	fh_copy(&resp->tfh, &argp->tfh);
-	resp->status = nfsd_rename(rqstp, &resp->ffh, argp->fname, argp->flen,
-				   &resp->tfh, argp->tname, argp->tlen);
-	resp->status = nfsd3_map_status(resp->status);
+	nfsd3_fh3_to_svc_fh(ffhp, &from->dir);
+	nfsd3_fh3_to_svc_fh(tfhp, &to->dir);
+	resp->status = nfsd3_check_filename(from->name.data,
+					    from->name.len);
+	if (resp->status != nfs_ok)
+		goto out;
+	resp->status = nfsd3_check_filename(to->name.data,
+					    to->name.len);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = nfsd_rename(rqstp, ffhp, (char *)from->name.data,
+				   from->name.len, tfhp,
+				   (char *)to->name.data,
+				   to->name.len);
+
+out:
+	if (resp->status == nfs_ok) {
+		struct RENAME3resok *resok = &resp->u.resok;
+
+		nfsd3_fill_wcc_data(rqstp, &resok->fromdir_wcc, ffhp);
+		nfsd3_fill_wcc_data(rqstp, &resok->todir_wcc, tfhp);
+	} else {
+		struct RENAME3resfail *resfail = &resp->u.resfail;
+
+		resp->status = nfsd3_map_status(resp->status);
+		nfsd3_fill_wcc_data(rqstp, &resfail->fromdir_wcc, ffhp);
+		nfsd3_fill_wcc_data(rqstp, &resfail->todir_wcc, tfhp);
+	}
+
+	fh_put(ffhp);
+	fh_put(tfhp);
 	return rpc_success;
 }
 
@@ -1791,16 +1839,15 @@ static const struct svc_procedure nfsd_procedures3[22] = {
 		.pc_name	= "RMDIR",
 	},
 	[NFSPROC3_RENAME] = {
-		.pc_func = nfsd3_proc_rename,
-		.pc_decode = nfs3svc_decode_renameargs,
-		.pc_encode = nfs3svc_encode_renameres,
-		.pc_release = nfs3svc_release_fhandle2,
-		.pc_argsize = sizeof(struct nfsd3_renameargs),
-		.pc_argzero = sizeof(struct nfsd3_renameargs),
-		.pc_ressize = sizeof(struct nfsd3_renameres),
-		.pc_cachetype = RC_REPLBUFF,
-		.pc_xdrressize = ST+WC+WC,
-		.pc_name = "RENAME",
+		.pc_func	= nfsd3_proc_rename,
+		.pc_decode	= nfs_svc_decode_RENAME3args,
+		.pc_encode	= nfs_svc_encode_RENAME3res,
+		.pc_argsize	= sizeof(struct RENAME3args_wrapper),
+		.pc_argzero	= 0,
+		.pc_ressize	= sizeof(struct RENAME3res),
+		.pc_cachetype	= RC_REPLBUFF,
+		.pc_xdrressize	= NFS3_RENAME3res_sz,
+		.pc_name	= "RENAME",
 	},
 	[NFSPROC3_LINK] = {
 		.pc_func = nfsd3_proc_link,
@@ -1910,13 +1957,13 @@ union nfsd3_xdrstore {
 	struct REMOVE3res		removeres;
 	struct RMDIR3args_wrapper	rmdirargs;
 	struct RMDIR3res		rmdirres;
-	struct nfsd3_renameargs		renameargs;
+	struct RENAME3args_wrapper	renameargs;
+	struct RENAME3res		renameres;
 	struct nfsd3_linkargs		linkargs;
 	struct nfsd3_readdirargs	readdirargs;
 	struct READLINK3res		readlinkres;
 	struct READ3res			readres;
 	struct nfsd3_writeres		writeres;
-	struct nfsd3_renameres		renameres;
 	struct nfsd3_linkres		linkres;
 	struct nfsd3_readdirres		readdirres;
 	struct nfsd3_fsstatres		fsstatres;
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index 1cfc79724450..3ec835e0f364 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -360,17 +360,6 @@ nfs3svc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 	return svcxdr_decode_nfs_fh3(xdr, &args->fh);
 }
 
-bool
-nfs3svc_decode_renameargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
-{
-	struct nfsd3_renameargs *args = rqstp->rq_argp;
-
-	return svcxdr_decode_diropargs3(xdr, &args->ffh,
-					&args->fname, &args->flen) &&
-		svcxdr_decode_diropargs3(xdr, &args->tfh,
-					 &args->tname, &args->tlen);
-}
-
 bool
 nfs3svc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 {
@@ -440,17 +429,6 @@ nfs3svc_decode_commitargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
  * XDR encode functions
  */
 
-/* RENAME */
-bool
-nfs3svc_encode_renameres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
-{
-	struct nfsd3_renameres *resp = rqstp->rq_resp;
-
-	return svcxdr_encode_nfsstat3(xdr, resp->status) &&
-		svcxdr_encode_wcc_data(rqstp, xdr, &resp->ffh) &&
-		svcxdr_encode_wcc_data(rqstp, xdr, &resp->tfh);
-}
-
 /* LINK */
 bool
 nfs3svc_encode_linkres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h
index fac60fb4cdf9..8a15781d7f3c 100644
--- a/fs/nfsd/xdr3.h
+++ b/fs/nfsd/xdr3.h
@@ -24,15 +24,6 @@ struct nfsd3_accessargs {
 	__u32			access;
 };
 
-struct nfsd3_renameargs {
-	struct svc_fh		ffh;
-	char *			fname;
-	unsigned int		flen;
-	struct svc_fh		tfh;
-	char *			tname;
-	unsigned int		tlen;
-};
-
 struct nfsd3_linkargs {
 	struct svc_fh		ffh;
 	struct svc_fh		tfh;
@@ -85,12 +76,6 @@ struct nfsd3_writeres {
 
 static_assert(offsetof(struct nfsd3_writeres, xdrgen) == 0);
 
-struct nfsd3_renameres {
-	__be32			status;
-	struct svc_fh		ffh;
-	struct svc_fh		tfh;
-};
-
 struct nfsd3_linkres {
 	__be32			status;
 	struct svc_fh		tfh;
@@ -165,14 +150,12 @@ struct nfsd3_fhandle_pair {
 };
 
 bool nfs3svc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
-bool nfs3svc_decode_renameargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_commitargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 
 bool nfs3svc_encode_accessres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
-bool nfs3svc_encode_renameres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_linkres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
-- 
2.55.0

[PATCH v3 22/34] NFSD: Use xdrgen XDR functions for the NFSv3 LINK procedure

[Chuck Lever]

Replace the NFSPROC3_LINK entry in the nfsd_procedures3 array with
an entry that dispatches the xdrgen-generated nfs_svc_decode_LINK3args
and nfs_svc_encode_LINK3res. A wrapper structure bridges the
generated xdrgen argument type and the legacy svc_fh representation
the NFSD VFS layer still uses; the result uses the generated LINK3res
type directly.

Filename validity is now checked by nfsd3_proc_link() so that a
proper NFS3ERR status code can be returned to the client rather than
GARBAGE_ARGS.

The pc_argzero field is now set to zero for the NFSv3 LINK procedure.
The xdrgen decoders are trusted to initialize all arguments in the
argp->xdrgen field, making the early defensive memset unnecessary.
The remaining argp fields are cleared as needed.

Because nfsd3_proc_link() now fills in the post-op attributes and
assembles the WCC data, that work moves out of the XDR result
encoder, and the references to the file handles can be released
directly by nfsd3_proc_link(). A separate ->pc_release callback is
thus no longer needed. This makes it straightforward to confirm that
the file handles are properly released during every error flow.

nfs3svc_decode_linkargs(), nfs3svc_encode_linkres(), and
nfs3svc_release_fhandle2() no longer have any callers, so they are
removed, and with them the now-orphaned svcxdr_decode_filename3() and
svcxdr_decode_diropargs3() decode helpers and the struct
nfsd3_fhandle_pair release type.

Signed-off-by: Chuck Lever <cel@kernel.org>
---
 fs/nfsd/nfs3proc.c | 82 ++++++++++++++++++++++++++++++++++------------
 fs/nfsd/nfs3xdr.c  | 63 -----------------------------------
 fs/nfsd/xdr3.h     | 23 -------------
 3 files changed, 61 insertions(+), 107 deletions(-)

diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index 7fd968fdb145..76963187de20 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -185,6 +185,14 @@ struct RENAME3args_wrapper {
 
 static_assert(offsetof(struct RENAME3args_wrapper, xdrgen) == 0);
 
+struct LINK3args_wrapper {
+	struct LINK3args	xdrgen;
+	struct svc_fh		ffh;
+	struct svc_fh		tfh;
+};
+
+static_assert(offsetof(struct LINK3args_wrapper, xdrgen) == 0);
+
 static int nfsd3_ftype3_to_mode(ftype3 ftype)
 {
 	switch (ftype) {
@@ -1406,17 +1414,50 @@ static __be32 nfsd3_proc_rename(struct svc_rqst *rqstp)
 	return rpc_success;
 }
 
-static __be32
-nfsd3_proc_link(struct svc_rqst *rqstp)
+/**
+ * nfsd3_proc_link - LINK: Create Link to an object
+ * @rqstp: RPC transaction context
+ *
+ * Return:
+ *   %rpc_success:		RPC executed successfully
+ *
+ * RPC synopsis:
+ *   LINK3res NFSPROC3_LINK(LINK3args) = 15;
+ */
+static __be32 nfsd3_proc_link(struct svc_rqst *rqstp)
 {
-	struct nfsd3_linkargs *argp = rqstp->rq_argp;
-	struct nfsd3_linkres  *resp = rqstp->rq_resp;
+	struct LINK3args_wrapper *argp = rqstp->rq_argp;
+	struct diropargs3 *link = &argp->xdrgen.link;
+	struct LINK3res *resp = rqstp->rq_resp;
+	struct svc_fh *ffhp = &argp->ffh;
+	struct svc_fh *tfhp = &argp->tfh;
 
-	fh_copy(&resp->fh,  &argp->ffh);
-	fh_copy(&resp->tfh, &argp->tfh);
-	resp->status = nfsd_link(rqstp, &resp->tfh, argp->tname, argp->tlen,
-				 &resp->fh);
-	resp->status = nfsd3_map_status(resp->status);
+	nfsd3_fh3_to_svc_fh(ffhp, &argp->xdrgen.file);
+	nfsd3_fh3_to_svc_fh(tfhp, &link->dir);
+	resp->status = nfsd3_check_filename(link->name.data,
+					    link->name.len);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = nfsd_link(rqstp, tfhp, (char *)link->name.data,
+				 link->name.len, ffhp);
+
+out:
+	if (resp->status == nfs_ok) {
+		struct LINK3resok *resok = &resp->u.resok;
+
+		nfsd3_fill_post_op_attr(rqstp, &resok->file_attributes, ffhp);
+		nfsd3_fill_wcc_data(rqstp, &resok->linkdir_wcc, tfhp);
+	} else {
+		struct LINK3resfail *resfail = &resp->u.resfail;
+
+		resp->status = nfsd3_map_status(resp->status);
+		nfsd3_fill_post_op_attr(rqstp, &resfail->file_attributes, ffhp);
+		nfsd3_fill_wcc_data(rqstp, &resfail->linkdir_wcc, tfhp);
+	}
+
+	fh_put(ffhp);
+	fh_put(tfhp);
 	return rpc_success;
 }
 
@@ -1850,16 +1891,15 @@ static const struct svc_procedure nfsd_procedures3[22] = {
 		.pc_name	= "RENAME",
 	},
 	[NFSPROC3_LINK] = {
-		.pc_func = nfsd3_proc_link,
-		.pc_decode = nfs3svc_decode_linkargs,
-		.pc_encode = nfs3svc_encode_linkres,
-		.pc_release = nfs3svc_release_fhandle2,
-		.pc_argsize = sizeof(struct nfsd3_linkargs),
-		.pc_argzero = sizeof(struct nfsd3_linkargs),
-		.pc_ressize = sizeof(struct nfsd3_linkres),
-		.pc_cachetype = RC_REPLBUFF,
-		.pc_xdrressize = ST+pAT+WC,
-		.pc_name = "LINK",
+		.pc_func	= nfsd3_proc_link,
+		.pc_decode	= nfs_svc_decode_LINK3args,
+		.pc_encode	= nfs_svc_encode_LINK3res,
+		.pc_argsize	= sizeof(struct LINK3args_wrapper),
+		.pc_argzero	= 0,
+		.pc_ressize	= sizeof(struct LINK3res),
+		.pc_cachetype	= RC_REPLBUFF,
+		.pc_xdrressize	= NFS3_LINK3res_sz,
+		.pc_name	= "LINK",
 	},
 	[NFSPROC3_READDIR] = {
 		.pc_func = nfsd3_proc_readdir,
@@ -1959,12 +1999,12 @@ union nfsd3_xdrstore {
 	struct RMDIR3res		rmdirres;
 	struct RENAME3args_wrapper	renameargs;
 	struct RENAME3res		renameres;
-	struct nfsd3_linkargs		linkargs;
+	struct LINK3args_wrapper	linkargs;
+	struct LINK3res			linkres;
 	struct nfsd3_readdirargs	readdirargs;
 	struct READLINK3res		readlinkres;
 	struct READ3res			readres;
 	struct nfsd3_writeres		writeres;
-	struct nfsd3_linkres		linkres;
 	struct nfsd3_readdirres		readdirres;
 	struct nfsd3_fsstatres		fsstatres;
 	struct nfsd3_fsinfores		fsinfores;
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index 3ec835e0f364..59e89b7f9d19 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -162,39 +162,6 @@ svcxdr_encode_writeverf3(struct xdr_stream *xdr, const __be32 *verf)
 	return true;
 }
 
-static bool
-svcxdr_decode_filename3(struct xdr_stream *xdr, char **name, unsigned int *len)
-{
-	u32 size, i;
-	__be32 *p;
-	char *c;
-
-	if (xdr_stream_decode_u32(xdr, &size) < 0)
-		return false;
-	if (size == 0 || size > NFS3_MAXNAMLEN)
-		return false;
-	p = xdr_inline_decode(xdr, size);
-	if (!p)
-		return false;
-
-	*len = size;
-	*name = (char *)p;
-	for (i = 0, c = *name; i < size; i++, c++) {
-		if (*c == '\0' || *c == '/')
-			return false;
-	}
-
-	return true;
-}
-
-static bool
-svcxdr_decode_diropargs3(struct xdr_stream *xdr, struct svc_fh *fhp,
-			 char **name, unsigned int *len)
-{
-	return svcxdr_decode_nfs_fh3(xdr, fhp) &&
-		svcxdr_decode_filename3(xdr, name, len);
-}
-
 static bool
 svcxdr_encode_fattr3(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 		     const struct svc_fh *fhp, const struct kstat *stat)
@@ -360,16 +327,6 @@ nfs3svc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 	return svcxdr_decode_nfs_fh3(xdr, &args->fh);
 }
 
-bool
-nfs3svc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
-{
-	struct nfsd3_linkargs *args = rqstp->rq_argp;
-
-	return svcxdr_decode_nfs_fh3(xdr, &args->ffh) &&
-		svcxdr_decode_diropargs3(xdr, &args->tfh,
-					 &args->tname, &args->tlen);
-}
-
 bool
 nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 {
@@ -429,17 +386,6 @@ nfs3svc_decode_commitargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
  * XDR encode functions
  */
 
-/* LINK */
-bool
-nfs3svc_encode_linkres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
-{
-	struct nfsd3_linkres *resp = rqstp->rq_resp;
-
-	return svcxdr_encode_nfsstat3(xdr, resp->status) &&
-		svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh) &&
-		svcxdr_encode_wcc_data(rqstp, xdr, &resp->tfh);
-}
-
 /* READDIR */
 bool
 nfs3svc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
@@ -840,12 +786,3 @@ nfs3svc_release_fhandle(struct svc_rqst *rqstp)
 
 	fh_put(&resp->fh);
 }
-
-void
-nfs3svc_release_fhandle2(struct svc_rqst *rqstp)
-{
-	struct nfsd3_fhandle_pair *resp = rqstp->rq_resp;
-
-	fh_put(&resp->fh1);
-	fh_put(&resp->fh2);
-}
diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h
index 8a15781d7f3c..9a2bdd5a0da5 100644
--- a/fs/nfsd/xdr3.h
+++ b/fs/nfsd/xdr3.h
@@ -24,13 +24,6 @@ struct nfsd3_accessargs {
 	__u32			access;
 };
 
-struct nfsd3_linkargs {
-	struct svc_fh		ffh;
-	struct svc_fh		tfh;
-	char *			tname;
-	unsigned int		tlen;
-};
-
 struct nfsd3_readdirargs {
 	struct svc_fh		fh;
 	__u64			cookie;
@@ -76,12 +69,6 @@ struct nfsd3_writeres {
 
 static_assert(offsetof(struct nfsd3_writeres, xdrgen) == 0);
 
-struct nfsd3_linkres {
-	__be32			status;
-	struct svc_fh		tfh;
-	struct svc_fh		fh;
-};
-
 struct nfsd3_readdirres {
 	/* Components of the reply */
 	__be32			status;
@@ -142,21 +129,12 @@ struct nfsd3_getaclres {
 	struct kstat		stat;
 };
 
-/* dummy type for release */
-struct nfsd3_fhandle_pair {
-	__u32			dummy;
-	struct svc_fh		fh1;
-	struct svc_fh		fh2;
-};
-
 bool nfs3svc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
-bool nfs3svc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_commitargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 
 bool nfs3svc_encode_accessres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
-bool nfs3svc_encode_linkres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, struct xdr_stream *xdr);
@@ -164,7 +142,6 @@ bool nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_commitres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 
 void nfs3svc_release_fhandle(struct svc_rqst *);
-void nfs3svc_release_fhandle2(struct svc_rqst *);
 
 void nfs3svc_encode_cookie3(struct nfsd3_readdirres *resp, u64 offset);
 int nfs3svc_encode_entry3(void *data, const char *name, int namlen,
-- 
2.55.0

[PATCH v3 23/34] NFSD: Use xdrgen XDR functions for the NFSv3 FSSTAT procedure

[Chuck Lever]

Replace the NFSPROC3_FSSTAT entry in the nfsd_procedures3 array with
an entry that dispatches the xdrgen-generated
nfs_svc_decode_FSSTAT3args and nfs_svc_encode_FSSTAT3res. A wrapper
structure bridges the generated xdrgen argument type and the legacy
svc_fh representation the NFSD VFS layer still uses. The result
wrapper carries a scratch kstatfs alongside the generated FSSTAT3res
type, which nfsd_statfs() fills before nfsd3_proc_fsstat() copies the
values into the encoded result.

The pc_argzero field is now set to zero for the NFSv3 FSSTAT
procedure. The xdrgen decoders are trusted to initialize all
arguments in the argp->xdrgen field, making the early defensive
memset unnecessary. The remaining argp fields are cleared as needed.

nfsd3_proc_fsstat() now sets the post-op attributes directly. This
makes it straightforward to confirm that the file handle is released
during every error flow.

nfs3svc_encode_fsstatres() no longer has any callers, so it is
removed, and with it the now-orphaned svcxdr_encode_fsstat3resok()
encode helper.

Signed-off-by: Chuck Lever <cel@kernel.org>
---
 fs/nfsd/nfs3proc.c | 71 +++++++++++++++++++++++++++++++++++-----------
 fs/nfsd/nfs3xdr.c  | 45 -----------------------------
 fs/nfsd/xdr3.h     |  6 ++--
 3 files changed, 57 insertions(+), 65 deletions(-)

diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index 76963187de20..0650bfa960e8 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -193,6 +193,13 @@ struct LINK3args_wrapper {
 
 static_assert(offsetof(struct LINK3args_wrapper, xdrgen) == 0);
 
+struct FSSTAT3args_wrapper {
+	struct FSSTAT3args	xdrgen;
+	struct svc_fh		fh;
+};
+
+static_assert(offsetof(struct FSSTAT3args_wrapper, xdrgen) == 0);
+
 static int nfsd3_ftype3_to_mode(ftype3 ftype)
 {
 	switch (ftype) {
@@ -1555,18 +1562,47 @@ nfsd3_proc_readdirplus(struct svc_rqst *rqstp)
 	return rpc_success;
 }
 
-/*
- * Get file system stats
+/**
+ * nfsd3_proc_fsstat - FSSTAT: Get dynamic file system information
+ * @rqstp: RPC transaction context
+ *
+ * Return:
+ *   %rpc_success:		RPC executed successfully
+ *
+ * RPC synopsis:
+ *   FSSTAT3res NFSPROC3_FSSTAT(FSSTAT3args) = 18;
  */
-static __be32
-nfsd3_proc_fsstat(struct svc_rqst *rqstp)
+static __be32 nfsd3_proc_fsstat(struct svc_rqst *rqstp)
 {
-	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct FSSTAT3args_wrapper *argp = rqstp->rq_argp;
 	struct nfsd3_fsstatres *resp = rqstp->rq_resp;
+	struct kstatfs *statp = &resp->stats;
+	struct svc_fh *fhp = &argp->fh;
 
-	resp->status = nfsd_statfs(rqstp, &argp->fh, &resp->stats, 0);
-	fh_put(&argp->fh);
-	resp->status = nfsd3_map_status(resp->status);
+	nfsd3_fh3_to_svc_fh(fhp, &argp->xdrgen.fsroot);
+
+	resp->xdrgen.status = nfsd_statfs(rqstp, fhp, statp, 0);
+
+	if (resp->xdrgen.status == nfs_ok) {
+		struct FSSTAT3resok *resok = &resp->xdrgen.u.resok;
+		u64 bs = statp->f_bsize;
+
+		resok->obj_attributes.attributes_follow = false;
+		resok->tbytes = bs * statp->f_blocks;
+		resok->fbytes = bs * statp->f_bfree;
+		resok->abytes = bs * statp->f_bavail;
+		resok->tfiles = statp->f_files;
+		resok->ffiles = statp->f_ffree;
+		resok->afiles = statp->f_ffree;
+		resok->invarsec = 0;
+	} else {
+		struct FSSTAT3resfail *resfail = &resp->xdrgen.u.resfail;
+
+		resp->xdrgen.status = nfsd3_map_status(resp->xdrgen.status);
+		resfail->obj_attributes.attributes_follow = false;
+	}
+
+	fh_put(fhp);
 	return rpc_success;
 }
 
@@ -1924,15 +1960,15 @@ static const struct svc_procedure nfsd_procedures3[22] = {
 		.pc_name = "READDIRPLUS",
 	},
 	[NFSPROC3_FSSTAT] = {
-		.pc_func = nfsd3_proc_fsstat,
-		.pc_decode = nfs3svc_decode_fhandleargs,
-		.pc_encode = nfs3svc_encode_fsstatres,
-		.pc_argsize = sizeof(struct nfsd3_fhandleargs),
-		.pc_argzero = sizeof(struct nfsd3_fhandleargs),
-		.pc_ressize = sizeof(struct nfsd3_fsstatres),
-		.pc_cachetype = RC_NOCACHE,
-		.pc_xdrressize = ST+pAT+2*6+1,
-		.pc_name = "FSSTAT",
+		.pc_func	= nfsd3_proc_fsstat,
+		.pc_decode	= nfs_svc_decode_FSSTAT3args,
+		.pc_encode	= nfs_svc_encode_FSSTAT3res,
+		.pc_argsize	= sizeof(struct FSSTAT3args_wrapper),
+		.pc_argzero	= 0,
+		.pc_ressize	= sizeof(struct nfsd3_fsstatres),
+		.pc_cachetype	= RC_NOCACHE,
+		.pc_xdrressize	= NFS3_FSSTAT3res_sz,
+		.pc_name	= "FSSTAT",
 	},
 	[NFSPROC3_FSINFO] = {
 		.pc_func = nfsd3_proc_fsinfo,
@@ -2006,6 +2042,7 @@ union nfsd3_xdrstore {
 	struct READ3res			readres;
 	struct nfsd3_writeres		writeres;
 	struct nfsd3_readdirres		readdirres;
+	struct FSSTAT3args_wrapper	fsstatargs;
 	struct nfsd3_fsstatres		fsstatres;
 	struct nfsd3_fsinfores		fsinfores;
 	struct nfsd3_pathconfres	pathconfres;
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index 59e89b7f9d19..0ca671bdd1c8 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -620,51 +620,6 @@ int nfs3svc_encode_entryplus3(void *data, const char *name, int namlen,
 	return -EINVAL;
 }
 
-static bool
-svcxdr_encode_fsstat3resok(struct xdr_stream *xdr,
-			   const struct nfsd3_fsstatres *resp)
-{
-	const struct kstatfs *s = &resp->stats;
-	u64 bs = s->f_bsize;
-	__be32 *p;
-
-	p = xdr_reserve_space(xdr, XDR_UNIT * 13);
-	if (!p)
-		return false;
-	p = xdr_encode_hyper(p, bs * s->f_blocks);	/* total bytes */
-	p = xdr_encode_hyper(p, bs * s->f_bfree);	/* free bytes */
-	p = xdr_encode_hyper(p, bs * s->f_bavail);	/* user available bytes */
-	p = xdr_encode_hyper(p, s->f_files);		/* total inodes */
-	p = xdr_encode_hyper(p, s->f_ffree);		/* free inodes */
-	p = xdr_encode_hyper(p, s->f_ffree);		/* user available inodes */
-	*p = cpu_to_be32(resp->invarsec);		/* mean unchanged time */
-
-	return true;
-}
-
-/* FSSTAT */
-bool
-nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
-{
-	struct nfsd3_fsstatres *resp = rqstp->rq_resp;
-
-	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
-		return false;
-	switch (resp->status) {
-	case nfs_ok:
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
-			return false;
-		if (!svcxdr_encode_fsstat3resok(xdr, resp))
-			return false;
-		break;
-	default:
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
-			return false;
-	}
-
-	return true;
-}
-
 static bool
 svcxdr_encode_fsinfo3resok(struct xdr_stream *xdr,
 			   const struct nfsd3_fsinfores *resp)
diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h
index 9a2bdd5a0da5..577a4beaafc3 100644
--- a/fs/nfsd/xdr3.h
+++ b/fs/nfsd/xdr3.h
@@ -86,11 +86,12 @@ struct nfsd3_readdirres {
 };
 
 struct nfsd3_fsstatres {
-	__be32			status;
+	struct FSSTAT3res	xdrgen;
 	struct kstatfs		stats;
-	__u32			invarsec;
 };
 
+static_assert(offsetof(struct nfsd3_fsstatres, xdrgen) == 0);
+
 struct nfsd3_fsinfores {
 	__be32			status;
 	__u32			f_rtmax;
@@ -136,7 +137,6 @@ bool nfs3svc_decode_commitargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 
 bool nfs3svc_encode_accessres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
-bool nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_commitres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
-- 
2.55.0

[PATCH v3 24/34] NFSD: Use xdrgen XDR functions for the NFSv3 FSINFO procedure

[Chuck Lever]

Replace the NFSPROC3_FSINFO entry in the nfsd_procedures3 array with
an entry that dispatches the xdrgen-generated nfs_svc_decode_FSINFO3args
and nfs_svc_encode_FSINFO3res. A wrapper structure bridges the
generated xdrgen argument type and the legacy svc_fh representation the
NFSD VFS layer still uses.

The pc_argzero field is now set to zero for the NFSv3 FSINFO
procedure. The xdrgen decoders are trusted to initialize all arguments
in the argp->xdrgen field, making the early defensive memset
unnecessary. The remaining argp fields are cleared as needed.

nfsd3_proc_fsinfo() now sets the post-op attributes directly. This
makes it straightforward to confirm that the file handle is released
during every error flow.

nfs3svc_encode_fsinfores() no longer has any callers, so it is
removed, and with it the now-orphaned svcxdr_encode_fsinfo3resok()
encode helper and the nfs3svc_time_delta constant it referenced.

Signed-off-by: Chuck Lever <cel@kernel.org>
---
 fs/nfsd/nfs3proc.c | 107 +++++++++++++++++++++++++++------------------
 fs/nfsd/nfs3xdr.c  |  55 -----------------------
 fs/nfsd/xdr3.h     |  14 ++----
 3 files changed, 67 insertions(+), 109 deletions(-)

diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index 0650bfa960e8..ff159d3a0fa6 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -24,9 +24,6 @@
 
 #define NFSDDBG_FACILITY		NFSDDBG_PROC
 
-#define NFS3_FSF_DEFAULT		0x001b
-#define NFS3_FSF_BILLYBOY		0x0018
-
 /*
  * Wrapper structures combine xdrgen types with legacy structures.
  * The xdrgen field must be first so the structure can be cast
@@ -200,6 +197,13 @@ struct FSSTAT3args_wrapper {
 
 static_assert(offsetof(struct FSSTAT3args_wrapper, xdrgen) == 0);
 
+struct FSINFO3args_wrapper {
+	struct FSINFO3args	xdrgen;
+	struct svc_fh		fh;
+};
+
+static_assert(offsetof(struct FSINFO3args_wrapper, xdrgen) == 0);
+
 static int nfsd3_ftype3_to_mode(ftype3 ftype)
 {
 	switch (ftype) {
@@ -1606,47 +1610,63 @@ static __be32 nfsd3_proc_fsstat(struct svc_rqst *rqstp)
 	return rpc_success;
 }
 
-/*
- * Get file system info
+/**
+ * nfsd3_proc_fsinfo - FSINFO: Get static file system information
+ * @rqstp: RPC transaction context
+ *
+ * Return:
+ *   %rpc_success:		RPC executed successfully
+ *
+ * RPC synopsis:
+ *   FSINFO3res NFSPROC3_FSINFO(FSINFO3args) = 19;
  */
-static __be32
-nfsd3_proc_fsinfo(struct svc_rqst *rqstp)
+static __be32 nfsd3_proc_fsinfo(struct svc_rqst *rqstp)
 {
-	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct FSINFO3args_wrapper *argp = rqstp->rq_argp;
 	struct nfsd3_fsinfores *resp = rqstp->rq_resp;
-	u32	max_blocksize = svc_max_payload(rqstp);
+	struct svc_fh *fhp = &argp->fh;
 
-	dprintk("nfsd: FSINFO(3)   %s\n",
-				SVCFH_fmt(&argp->fh));
+	nfsd3_fh3_to_svc_fh(fhp, &argp->xdrgen.fsroot);
 
-	resp->f_rtmax  = max_blocksize;
-	resp->f_rtpref = max_blocksize;
-	resp->f_rtmult = PAGE_SIZE;
-	resp->f_wtmax  = max_blocksize;
-	resp->f_wtpref = max_blocksize;
-	resp->f_wtmult = PAGE_SIZE;
-	resp->f_dtpref = max_blocksize;
-	resp->f_maxfilesize = ~(u32) 0;
-	resp->f_properties = NFS3_FSF_DEFAULT;
+	resp->xdrgen.status = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP |
+					NFSD_MAY_BYPASS_GSS_ON_ROOT);
 
-	resp->status = fh_verify(rqstp, &argp->fh, 0,
-				 NFSD_MAY_NOP | NFSD_MAY_BYPASS_GSS_ON_ROOT);
+	if (resp->xdrgen.status == nfs_ok) {
+		struct FSINFO3resok *resok = &resp->xdrgen.u.resok;
+		struct super_block *sb = fhp->fh_dentry->d_sb;
+		u32 max_blocksize = svc_max_payload(rqstp);
 
-	/* Check special features of the file system. May request
-	 * different read/write sizes for file systems known to have
-	 * problems with large blocks */
-	if (resp->status == nfs_ok) {
-		struct super_block *sb = argp->fh.fh_dentry->d_sb;
+		resok->obj_attributes.attributes_follow = false;
+		resok->rtmax = max_blocksize;
+		resok->rtpref = max_blocksize;
+		resok->rtmult = PAGE_SIZE;
+		resok->wtmax = max_blocksize;
+		resok->wtpref = max_blocksize;
+		resok->wtmult = PAGE_SIZE;
+		resok->dtpref = max_blocksize;
+		resok->maxfilesize = ~(u32)0;
+		/* NFSD is accurate to the nearest second. */
+		resok->time_delta.seconds = 1;
+		resok->time_delta.nseconds = 0;
+		resok->properties = FSF3_LINK | FSF3_SYMLINK |
+				    FSF3_HOMOGENEOUS | FSF3_CANSETTIME;
 
-		/* Note that we don't care for remote fs's here */
-		if (sb->s_magic == MSDOS_SUPER_MAGIC) {
-			resp->f_properties = NFS3_FSF_BILLYBOY;
-		}
-		resp->f_maxfilesize = sb->s_maxbytes;
+		/*
+		 * Check special features of the file system. May
+		 * request different read/write sizes for file systems
+		 * known to have problems with large blocks.
+		 */
+		if (sb->s_magic == MSDOS_SUPER_MAGIC)
+			resok->properties = FSF3_HOMOGENEOUS | FSF3_CANSETTIME;
+		resok->maxfilesize = sb->s_maxbytes;
+	} else {
+		struct FSINFO3resfail *resfail = &resp->xdrgen.u.resfail;
+
+		resp->xdrgen.status = nfsd3_map_status(resp->xdrgen.status);
+		resfail->obj_attributes.attributes_follow = false;
 	}
 
-	fh_put(&argp->fh);
-	resp->status = nfsd3_map_status(resp->status);
+	fh_put(fhp);
 	return rpc_success;
 }
 
@@ -1971,15 +1991,15 @@ static const struct svc_procedure nfsd_procedures3[22] = {
 		.pc_name	= "FSSTAT",
 	},
 	[NFSPROC3_FSINFO] = {
-		.pc_func = nfsd3_proc_fsinfo,
-		.pc_decode = nfs3svc_decode_fhandleargs,
-		.pc_encode = nfs3svc_encode_fsinfores,
-		.pc_argsize = sizeof(struct nfsd3_fhandleargs),
-		.pc_argzero = sizeof(struct nfsd3_fhandleargs),
-		.pc_ressize = sizeof(struct nfsd3_fsinfores),
-		.pc_cachetype = RC_NOCACHE,
-		.pc_xdrressize = ST+pAT+12,
-		.pc_name = "FSINFO",
+		.pc_func	= nfsd3_proc_fsinfo,
+		.pc_decode	= nfs_svc_decode_FSINFO3args,
+		.pc_encode	= nfs_svc_encode_FSINFO3res,
+		.pc_argsize	= sizeof(struct FSINFO3args_wrapper),
+		.pc_argzero	= 0,
+		.pc_ressize	= sizeof(struct nfsd3_fsinfores),
+		.pc_cachetype	= RC_NOCACHE,
+		.pc_xdrressize	= NFS3_FSINFO3res_sz,
+		.pc_name	= "FSINFO",
 	},
 	[NFSPROC3_PATHCONF] = {
 		.pc_func = nfsd3_proc_pathconf,
@@ -2044,6 +2064,7 @@ union nfsd3_xdrstore {
 	struct nfsd3_readdirres		readdirres;
 	struct FSSTAT3args_wrapper	fsstatargs;
 	struct nfsd3_fsstatres		fsstatres;
+	struct FSINFO3args_wrapper	fsinfoargs;
 	struct nfsd3_fsinfores		fsinfores;
 	struct nfsd3_pathconfres	pathconfres;
 	struct nfsd3_commitres		commitres;
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index 0ca671bdd1c8..9e400a97e435 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -24,15 +24,6 @@ static const struct svc_fh nfs3svc_null_fh = {
 	.fh_no_wcc	= true,
 };
 
-/*
- * time_delta. {1, 0} means the server is accurate only
- * to the nearest second.
- */
-static const struct timespec64 nfs3svc_time_delta = {
-	.tv_sec		= 1,
-	.tv_nsec	= 0,
-};
-
 /*
  * Mapping of S_IF* types to NFS file types
  */
@@ -620,52 +611,6 @@ int nfs3svc_encode_entryplus3(void *data, const char *name, int namlen,
 	return -EINVAL;
 }
 
-static bool
-svcxdr_encode_fsinfo3resok(struct xdr_stream *xdr,
-			   const struct nfsd3_fsinfores *resp)
-{
-	__be32 *p;
-
-	p = xdr_reserve_space(xdr, XDR_UNIT * 12);
-	if (!p)
-		return false;
-	*p++ = cpu_to_be32(resp->f_rtmax);
-	*p++ = cpu_to_be32(resp->f_rtpref);
-	*p++ = cpu_to_be32(resp->f_rtmult);
-	*p++ = cpu_to_be32(resp->f_wtmax);
-	*p++ = cpu_to_be32(resp->f_wtpref);
-	*p++ = cpu_to_be32(resp->f_wtmult);
-	*p++ = cpu_to_be32(resp->f_dtpref);
-	p = xdr_encode_hyper(p, resp->f_maxfilesize);
-	p = encode_nfstime3(p, &nfs3svc_time_delta);
-	*p = cpu_to_be32(resp->f_properties);
-
-	return true;
-}
-
-/* FSINFO */
-bool
-nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, struct xdr_stream *xdr)
-{
-	struct nfsd3_fsinfores *resp = rqstp->rq_resp;
-
-	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
-		return false;
-	switch (resp->status) {
-	case nfs_ok:
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
-			return false;
-		if (!svcxdr_encode_fsinfo3resok(xdr, resp))
-			return false;
-		break;
-	default:
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
-			return false;
-	}
-
-	return true;
-}
-
 static bool
 svcxdr_encode_pathconf3resok(struct xdr_stream *xdr,
 			     const struct nfsd3_pathconfres *resp)
diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h
index 577a4beaafc3..979b9ea5b86d 100644
--- a/fs/nfsd/xdr3.h
+++ b/fs/nfsd/xdr3.h
@@ -93,18 +93,11 @@ struct nfsd3_fsstatres {
 static_assert(offsetof(struct nfsd3_fsstatres, xdrgen) == 0);
 
 struct nfsd3_fsinfores {
-	__be32			status;
-	__u32			f_rtmax;
-	__u32			f_rtpref;
-	__u32			f_rtmult;
-	__u32			f_wtmax;
-	__u32			f_wtpref;
-	__u32			f_wtmult;
-	__u32			f_dtpref;
-	__u64			f_maxfilesize;
-	__u32			f_properties;
+	struct FSINFO3res	xdrgen;
 };
 
+static_assert(offsetof(struct nfsd3_fsinfores, xdrgen) == 0);
+
 struct nfsd3_pathconfres {
 	__be32			status;
 	__u32			p_link_max;
@@ -137,7 +130,6 @@ bool nfs3svc_decode_commitargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 
 bool nfs3svc_encode_accessres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
-bool nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_commitres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 
-- 
2.55.0

[PATCH v3 25/34] NFSD: Use xdrgen XDR functions for the NFSv3 PATHCONF procedure

[Chuck Lever]

Replace the NFSPROC3_PATHCONF entry in the nfsd_procedures3 array
with an entry that dispatches the xdrgen-generated
nfs_svc_decode_PATHCONF3args and nfs_svc_encode_PATHCONF3res. A
wrapper structure bridges the generated xdrgen argument type and the
legacy svc_fh representation the NFSD VFS layer still uses.

The pc_argzero field is now set to zero for the NFSv3 PATHCONF
procedure. The xdrgen decoders are trusted to initialize all
arguments in the argp->xdrgen field, making the early defensive
memset unnecessary. The remaining argp fields are cleared as needed.

nfsd3_proc_pathconf() now sets the post-op attributes directly. This
makes it straightforward to confirm that the file handle is released
during every error flow.

nfs3svc_encode_pathconfres() no longer has any callers, so it is
removed, and with it the now-orphaned svcxdr_encode_pathconf3resok()
encode helper and the nfs3svc_null_fh constant it referenced. This
was also the last user of the shared nfs3svc_decode_fhandleargs()
decoder, so that too is removed.

Signed-off-by: Chuck Lever <cel@kernel.org>
---
 fs/nfsd/nfs3proc.c | 94 +++++++++++++++++++++++++++-------------------
 fs/nfsd/nfs3xdr.c  | 57 ----------------------------
 fs/nfsd/xdr3.h     | 12 ++----
 3 files changed, 59 insertions(+), 104 deletions(-)

diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index ff159d3a0fa6..c1bb9ede4535 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -204,6 +204,13 @@ struct FSINFO3args_wrapper {
 
 static_assert(offsetof(struct FSINFO3args_wrapper, xdrgen) == 0);
 
+struct PATHCONF3args_wrapper {
+	struct PATHCONF3args	xdrgen;
+	struct svc_fh		fh;
+};
+
+static_assert(offsetof(struct PATHCONF3args_wrapper, xdrgen) == 0);
+
 static int nfsd3_ftype3_to_mode(ftype3 ftype)
 {
 	switch (ftype) {
@@ -1670,40 +1677,47 @@ static __be32 nfsd3_proc_fsinfo(struct svc_rqst *rqstp)
 	return rpc_success;
 }
 
-/*
- * Get pathconf info for the specified file
+/**
+ * nfsd3_proc_pathconf - PATHCONF: Retrieve POSIX information
+ * @rqstp: RPC transaction context
+ *
+ * Return:
+ *   %rpc_success:		RPC executed successfully
+ *
+ * RPC synopsis:
+ *   PATHCONF3res NFSPROC3_PATHCONF(PATHCONF3args) = 20;
  */
-static __be32
-nfsd3_proc_pathconf(struct svc_rqst *rqstp)
+static __be32 nfsd3_proc_pathconf(struct svc_rqst *rqstp)
 {
-	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct PATHCONF3args_wrapper *argp = rqstp->rq_argp;
 	struct nfsd3_pathconfres *resp = rqstp->rq_resp;
+	struct svc_fh *fhp = &argp->fh;
 
-	dprintk("nfsd: PATHCONF(3) %s\n",
-				SVCFH_fmt(&argp->fh));
+	nfsd3_fh3_to_svc_fh(fhp, &argp->xdrgen.object);
 
-	/* Set default pathconf */
-	resp->p_link_max = 255;		/* at least */
-	resp->p_name_max = 255;		/* at least */
-	resp->p_no_trunc = 0;
-	resp->p_chown_restricted = 1;
-	resp->p_case_insensitive = false;
-	resp->p_case_preserving = true;
+	resp->xdrgen.status = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
 
-	resp->status = fh_verify(rqstp, &argp->fh, 0, NFSD_MAY_NOP);
-
-	if (resp->status == nfs_ok) {
-		struct super_block *sb = argp->fh.fh_dentry->d_sb;
+	if (resp->xdrgen.status == nfs_ok) {
+		struct PATHCONF3resok *resok = &resp->xdrgen.u.resok;
+		struct super_block *sb = fhp->fh_dentry->d_sb;
 		int err;
 
+		resok->obj_attributes.attributes_follow = false;
+		resok->linkmax = 255;
+		resok->name_max = NAME_MAX;
+		resok->no_trunc = false;
+		resok->chown_restricted = true;
+		resok->case_insensitive = false;
+		resok->case_preserving = true;
+
 		if (sb->s_magic == EXT2_SUPER_MAGIC) {
-			resp->p_link_max = EXT2_LINK_MAX;
-			resp->p_name_max = EXT2_NAME_LEN;
+			resok->linkmax = EXT2_LINK_MAX;
+			resok->name_max = EXT2_NAME_LEN;
 		}
 
-		err = nfsd_get_case_info(argp->fh.fh_dentry,
-					 &resp->p_case_insensitive,
-					 &resp->p_case_preserving);
+		err = nfsd_get_case_info(fhp->fh_dentry,
+					 &resok->case_insensitive,
+					 &resok->case_preserving);
 		/*
 		 * RFC 1813 lists NFS3ERR_STALE, NFS3ERR_BADHANDLE, and
 		 * NFS3ERR_SERVERFAULT as the only PATHCONF errors.
@@ -1720,19 +1734,23 @@ nfsd3_proc_pathconf(struct svc_rqst *rqstp)
 			 * handle is unusable without implying a server
 			 * malfunction.
 			 */
-			resp->status = nfserr_stale;
+			resp->xdrgen.status = nfserr_stale;
 			break;
 		case -ESTALE:
-			resp->status = nfserr_stale;
+			resp->xdrgen.status = nfserr_stale;
 			break;
 		default:
-			resp->status = nfserr_serverfault;
+			resp->xdrgen.status = nfserr_serverfault;
 			break;
 		}
+	} else {
+		struct PATHCONF3resfail *resfail = &resp->xdrgen.u.resfail;
+
+		resp->xdrgen.status = nfsd3_map_status(resp->xdrgen.status);
+		resfail->obj_attributes.attributes_follow = false;
 	}
 
-	fh_put(&argp->fh);
-	resp->status = nfsd3_map_status(resp->status);
+	fh_put(fhp);
 	return rpc_success;
 }
 
@@ -1770,7 +1788,6 @@ nfsd3_proc_commit(struct svc_rqst *rqstp)
  * Only the results of non-idempotent operations are cached.
  */
 #define nfsd3_readdirplusargs		nfsd3_readdirargs
-#define nfsd3_fhandleargs		nfsd_fhandle
 
 #define ST 1		/* status*/
 #define AT 21		/* attributes */
@@ -2002,15 +2019,15 @@ static const struct svc_procedure nfsd_procedures3[22] = {
 		.pc_name	= "FSINFO",
 	},
 	[NFSPROC3_PATHCONF] = {
-		.pc_func = nfsd3_proc_pathconf,
-		.pc_decode = nfs3svc_decode_fhandleargs,
-		.pc_encode = nfs3svc_encode_pathconfres,
-		.pc_argsize = sizeof(struct nfsd3_fhandleargs),
-		.pc_argzero = sizeof(struct nfsd3_fhandleargs),
-		.pc_ressize = sizeof(struct nfsd3_pathconfres),
-		.pc_cachetype = RC_NOCACHE,
-		.pc_xdrressize = ST+pAT+6,
-		.pc_name = "PATHCONF",
+		.pc_func	= nfsd3_proc_pathconf,
+		.pc_decode	= nfs_svc_decode_PATHCONF3args,
+		.pc_encode	= nfs_svc_encode_PATHCONF3res,
+		.pc_argsize	= sizeof(struct PATHCONF3args_wrapper),
+		.pc_argzero	= 0,
+		.pc_ressize	= sizeof(struct nfsd3_pathconfres),
+		.pc_cachetype	= RC_NOCACHE,
+		.pc_xdrressize	= NFS3_PATHCONF3res_sz,
+		.pc_name	= "PATHCONF",
 	},
 	[NFSPROC3_COMMIT] = {
 		.pc_func = nfsd3_proc_commit,
@@ -2066,6 +2083,7 @@ union nfsd3_xdrstore {
 	struct nfsd3_fsstatres		fsstatres;
 	struct FSINFO3args_wrapper	fsinfoargs;
 	struct nfsd3_fsinfores		fsinfores;
+	struct PATHCONF3args_wrapper	pathconfargs;
 	struct nfsd3_pathconfres	pathconfres;
 	struct nfsd3_commitres		commitres;
 	struct nfsd3_getaclres		getaclres;
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index 9e400a97e435..3da66b5cac22 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -17,13 +17,6 @@
 #include "vfs.h"
 #include "nfserr.h"
 
-/*
- * Force construction of an empty post-op attr
- */
-static const struct svc_fh nfs3svc_null_fh = {
-	.fh_no_wcc	= true,
-};
-
 /*
  * Mapping of S_IF* types to NFS file types
  */
@@ -310,14 +303,6 @@ svcxdr_encode_wcc_data(struct svc_rqst *rqstp, struct xdr_stream *xdr,
  * XDR decode functions
  */
 
-bool
-nfs3svc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
-{
-	struct nfsd_fhandle *args = rqstp->rq_argp;
-
-	return svcxdr_decode_nfs_fh3(xdr, &args->fh);
-}
-
 bool
 nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 {
@@ -611,48 +596,6 @@ int nfs3svc_encode_entryplus3(void *data, const char *name, int namlen,
 	return -EINVAL;
 }
 
-static bool
-svcxdr_encode_pathconf3resok(struct xdr_stream *xdr,
-			     const struct nfsd3_pathconfres *resp)
-{
-	__be32 *p;
-
-	p = xdr_reserve_space(xdr, XDR_UNIT * 6);
-	if (!p)
-		return false;
-	*p++ = cpu_to_be32(resp->p_link_max);
-	*p++ = cpu_to_be32(resp->p_name_max);
-	p = xdr_encode_bool(p, resp->p_no_trunc);
-	p = xdr_encode_bool(p, resp->p_chown_restricted);
-	p = xdr_encode_bool(p, resp->p_case_insensitive);
-	xdr_encode_bool(p, resp->p_case_preserving);
-
-	return true;
-}
-
-/* PATHCONF */
-bool
-nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
-{
-	struct nfsd3_pathconfres *resp = rqstp->rq_resp;
-
-	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
-		return false;
-	switch (resp->status) {
-	case nfs_ok:
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
-			return false;
-		if (!svcxdr_encode_pathconf3resok(xdr, resp))
-			return false;
-		break;
-	default:
-		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
-			return false;
-	}
-
-	return true;
-}
-
 /* COMMIT */
 bool
 nfs3svc_encode_commitres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h
index 979b9ea5b86d..6428d9a190b0 100644
--- a/fs/nfsd/xdr3.h
+++ b/fs/nfsd/xdr3.h
@@ -99,15 +99,11 @@ struct nfsd3_fsinfores {
 static_assert(offsetof(struct nfsd3_fsinfores, xdrgen) == 0);
 
 struct nfsd3_pathconfres {
-	__be32			status;
-	__u32			p_link_max;
-	__u32			p_name_max;
-	__u32			p_no_trunc;
-	__u32			p_chown_restricted;
-	bool			p_case_insensitive;
-	bool			p_case_preserving;
+	struct PATHCONF3res	xdrgen;
 };
 
+static_assert(offsetof(struct nfsd3_pathconfres, xdrgen) == 0);
+
 struct nfsd3_commitres {
 	__be32			status;
 	struct svc_fh		fh;
@@ -123,14 +119,12 @@ struct nfsd3_getaclres {
 	struct kstat		stat;
 };
 
-bool nfs3svc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_commitargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 
 bool nfs3svc_encode_accessres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
-bool nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_commitres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 
 void nfs3svc_release_fhandle(struct svc_rqst *);
-- 
2.55.0

[PATCH v3 26/34] NFSD: Use xdrgen XDR functions for the NFSv3 COMMIT procedure

[Chuck Lever]

Replace the NFSPROC3_COMMIT entry in the nfsd_procedures3 array with
an entry that dispatches the xdrgen-generated
nfs_svc_decode_COMMIT3args and nfs_svc_encode_COMMIT3res. A wrapper
structure bridges the generated xdrgen argument type and the legacy
svc_fh representation the NFSD VFS layer still uses.

The pc_argzero field is now set to zero for the NFSv3 COMMIT
procedure. The xdrgen decoders are trusted to initialize all
arguments in the argp->xdrgen field, making the early defensive
memset unnecessary. The remaining argp fields are cleared as needed.

Because nfsd3_proc_commit() now fills in the WCC data, including
both the pre-op and post-op attributes, the fh_getattr() calls are
made in the proc function rather than in the XDR result encoder, and
the reference to the file handle can be released directly by
nfsd3_proc_commit(). A separate ->pc_release callback is thus no
longer needed. This makes it straightforward to confirm that the
file handle is properly released during every error flow.

nfs3svc_decode_commitargs() and nfs3svc_encode_commitres() no longer
have any callers, so they are removed. COMMIT was the last caller of
the hand-written WCC encoders, so svcxdr_encode_wcc_data() and its
svcxdr_encode_pre_op_attr() and svcxdr_encode_wcc_attr() helpers are
removed as well, along with the now-orphaned svcxdr_encode_writeverf3()
encode helper.

Signed-off-by: Chuck Lever <cel@kernel.org>
---
 fs/nfsd/nfs3proc.c |  80 +++++++++++++++++++-------------
 fs/nfsd/nfs3xdr.c  | 113 ---------------------------------------------
 fs/nfsd/xdr3.h     |  14 ++----
 3 files changed, 52 insertions(+), 155 deletions(-)

diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index c1bb9ede4535..7a03c9ed8fbd 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -211,6 +211,13 @@ struct PATHCONF3args_wrapper {
 
 static_assert(offsetof(struct PATHCONF3args_wrapper, xdrgen) == 0);
 
+struct COMMIT3args_wrapper {
+	struct COMMIT3args	xdrgen;
+	struct svc_fh		fh;
+};
+
+static_assert(offsetof(struct COMMIT3args_wrapper, xdrgen) == 0);
+
 static int nfsd3_ftype3_to_mode(ftype3 ftype)
 {
 	switch (ftype) {
@@ -1754,31 +1761,47 @@ static __be32 nfsd3_proc_pathconf(struct svc_rqst *rqstp)
 	return rpc_success;
 }
 
-/*
- * Commit a file (range) to stable storage.
+/**
+ * nfsd3_proc_commit - COMMIT: Commit cached data on a server to stable storage
+ * @rqstp: RPC transaction context
+ *
+ * Return:
+ *   %rpc_success:		RPC executed successfully
+ *
+ * RPC synopsis:
+ *   COMMIT3res NFSPROC3_COMMIT(COMMIT3args) = 21;
  */
-static __be32
-nfsd3_proc_commit(struct svc_rqst *rqstp)
+static __be32 nfsd3_proc_commit(struct svc_rqst *rqstp)
 {
-	struct nfsd3_commitargs *argp = rqstp->rq_argp;
+	struct COMMIT3args_wrapper *argp = rqstp->rq_argp;
 	struct nfsd3_commitres *resp = rqstp->rq_resp;
+	struct svc_fh *fhp = &argp->fh;
 	struct nfsd_file *nf;
 
-	dprintk("nfsd: COMMIT(3)   %s %u@%Lu\n",
-				SVCFH_fmt(&argp->fh),
-				argp->count,
-				(unsigned long long) argp->offset);
+	nfsd3_fh3_to_svc_fh(fhp, &argp->xdrgen.file);
 
-	fh_copy(&resp->fh, &argp->fh);
-	resp->status = nfsd_file_acquire_gc(rqstp, &resp->fh, NFSD_MAY_WRITE |
-					    NFSD_MAY_NOT_BREAK_LEASE, &nf);
-	if (resp->status)
+	resp->xdrgen.status = nfsd_file_acquire_gc(rqstp, fhp, NFSD_MAY_WRITE |
+						   NFSD_MAY_NOT_BREAK_LEASE, &nf);
+	if (resp->xdrgen.status)
 		goto out;
-	resp->status = nfsd_commit(rqstp, &resp->fh, nf, argp->offset,
-				   argp->count, resp->verf);
+	resp->xdrgen.status = nfsd_commit(rqstp, fhp, nf,
+					  argp->xdrgen.offset, argp->xdrgen.count,
+					  (__be32 *)resp->xdrgen.u.resok.verf);
 	nfsd_file_put(nf);
+
 out:
-	resp->status = nfsd3_map_status(resp->status);
+	if (resp->xdrgen.status == nfs_ok) {
+		struct COMMIT3resok *resok = &resp->xdrgen.u.resok;
+
+		nfsd3_fill_wcc_data(rqstp, &resok->file_wcc, fhp);
+	} else {
+		struct COMMIT3resfail *resfail = &resp->xdrgen.u.resfail;
+
+		resp->xdrgen.status = nfsd3_map_status(resp->xdrgen.status);
+		nfsd3_fill_wcc_data(rqstp, &resfail->file_wcc, fhp);
+	}
+
+	fh_put(fhp);
 	return rpc_success;
 }
 
@@ -1789,11 +1812,6 @@ nfsd3_proc_commit(struct svc_rqst *rqstp)
  */
 #define nfsd3_readdirplusargs		nfsd3_readdirargs
 
-#define ST 1		/* status*/
-#define AT 21		/* attributes */
-#define pAT (1+AT)	/* post attributes - conditional */
-#define WC (7+pAT)	/* WCC attributes */
-
 static const struct svc_procedure nfsd_procedures3[22] = {
 	[NFSPROC3_NULL] = {
 		.pc_func	= nfsd3_proc_null,
@@ -2030,16 +2048,15 @@ static const struct svc_procedure nfsd_procedures3[22] = {
 		.pc_name	= "PATHCONF",
 	},
 	[NFSPROC3_COMMIT] = {
-		.pc_func = nfsd3_proc_commit,
-		.pc_decode = nfs3svc_decode_commitargs,
-		.pc_encode = nfs3svc_encode_commitres,
-		.pc_release = nfs3svc_release_fhandle,
-		.pc_argsize = sizeof(struct nfsd3_commitargs),
-		.pc_argzero = sizeof(struct nfsd3_commitargs),
-		.pc_ressize = sizeof(struct nfsd3_commitres),
-		.pc_cachetype = RC_NOCACHE,
-		.pc_xdrressize = ST+WC+2,
-		.pc_name = "COMMIT",
+		.pc_func	= nfsd3_proc_commit,
+		.pc_decode	= nfs_svc_decode_COMMIT3args,
+		.pc_encode	= nfs_svc_encode_COMMIT3res,
+		.pc_argsize	= sizeof(struct COMMIT3args_wrapper),
+		.pc_argzero	= 0,
+		.pc_ressize	= sizeof(struct nfsd3_commitres),
+		.pc_cachetype	= RC_NOCACHE,
+		.pc_xdrressize	= NFS3_COMMIT3res_sz,
+		.pc_name	= "COMMIT",
 	},
 };
 
@@ -2085,6 +2102,7 @@ union nfsd3_xdrstore {
 	struct nfsd3_fsinfores		fsinfores;
 	struct PATHCONF3args_wrapper	pathconfargs;
 	struct nfsd3_pathconfres	pathconfres;
+	struct COMMIT3args_wrapper	commitargs;
 	struct nfsd3_commitres		commitres;
 	struct nfsd3_getaclres		getaclres;
 };
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index 3da66b5cac22..e93983d08aa5 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -133,19 +133,6 @@ svcxdr_encode_cookieverf3(struct xdr_stream *xdr, const __be32 *verf)
 	return true;
 }
 
-static bool
-svcxdr_encode_writeverf3(struct xdr_stream *xdr, const __be32 *verf)
-{
-	__be32 *p;
-
-	p = xdr_reserve_space(xdr, NFS3_WRITEVERFSIZE);
-	if (!p)
-		return false;
-	memcpy(p, verf, NFS3_WRITEVERFSIZE);
-
-	return true;
-}
-
 static bool
 svcxdr_encode_fattr3(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 		     const struct svc_fh *fhp, const struct kstat *stat)
@@ -198,35 +185,6 @@ svcxdr_encode_fattr3(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 	return true;
 }
 
-static bool
-svcxdr_encode_wcc_attr(struct xdr_stream *xdr, const struct svc_fh *fhp)
-{
-	__be32 *p;
-
-	p = xdr_reserve_space(xdr, XDR_UNIT * 6);
-	if (!p)
-		return false;
-	p = xdr_encode_hyper(p, (u64)fhp->fh_pre_size);
-	p = encode_nfstime3(p, &fhp->fh_pre_mtime);
-	encode_nfstime3(p, &fhp->fh_pre_ctime);
-
-	return true;
-}
-
-static bool
-svcxdr_encode_pre_op_attr(struct xdr_stream *xdr, const struct svc_fh *fhp)
-{
-	if (!fhp->fh_pre_saved) {
-		if (xdr_stream_encode_item_absent(xdr) < 0)
-			return false;
-		return true;
-	}
-
-	if (xdr_stream_encode_item_present(xdr) < 0)
-		return false;
-	return svcxdr_encode_wcc_attr(xdr, fhp);
-}
-
 /**
  * svcxdr_encode_post_op_attr - Encode NFSv3 post-op attributes
  * @rqstp: Context of a completed RPC transaction
@@ -266,39 +224,6 @@ svcxdr_encode_post_op_attr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 	return xdr_stream_encode_item_absent(xdr) > 0;
 }
 
-/*
- * Encode weak cache consistency data
- */
-static bool
-svcxdr_encode_wcc_data(struct svc_rqst *rqstp, struct xdr_stream *xdr,
-		       const struct svc_fh *fhp)
-{
-	struct dentry *dentry = fhp->fh_dentry;
-
-	if (!dentry || !d_really_is_positive(dentry) || !fhp->fh_post_saved)
-		goto neither;
-
-	/* before */
-	if (!svcxdr_encode_pre_op_attr(xdr, fhp))
-		return false;
-
-	/* after */
-	if (xdr_stream_encode_item_present(xdr) < 0)
-		return false;
-	if (!svcxdr_encode_fattr3(rqstp, xdr, fhp, &fhp->fh_post_attr))
-		return false;
-
-	return true;
-
-neither:
-	if (xdr_stream_encode_item_absent(xdr) < 0)
-		return false;
-	if (!svcxdr_encode_post_op_attr(rqstp, xdr, fhp))
-		return false;
-
-	return true;
-}
-
 /*
  * XDR decode functions
  */
@@ -343,21 +268,6 @@ nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 	return true;
 }
 
-bool
-nfs3svc_decode_commitargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
-{
-	struct nfsd3_commitargs *args = rqstp->rq_argp;
-
-	if (!svcxdr_decode_nfs_fh3(xdr, &args->fh))
-		return false;
-	if (xdr_stream_decode_u64(xdr, &args->offset) < 0)
-		return false;
-	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
-		return false;
-
-	return true;
-}
-
 /*
  * XDR encode functions
  */
@@ -596,29 +506,6 @@ int nfs3svc_encode_entryplus3(void *data, const char *name, int namlen,
 	return -EINVAL;
 }
 
-/* COMMIT */
-bool
-nfs3svc_encode_commitres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
-{
-	struct nfsd3_commitres *resp = rqstp->rq_resp;
-
-	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
-		return false;
-	switch (resp->status) {
-	case nfs_ok:
-		if (!svcxdr_encode_wcc_data(rqstp, xdr, &resp->fh))
-			return false;
-		if (!svcxdr_encode_writeverf3(xdr, resp->verf))
-			return false;
-		break;
-	default:
-		if (!svcxdr_encode_wcc_data(rqstp, xdr, &resp->fh))
-			return false;
-	}
-
-	return true;
-}
-
 /*
  * XDR release functions
  */
diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h
index 6428d9a190b0..e2110f9a126b 100644
--- a/fs/nfsd/xdr3.h
+++ b/fs/nfsd/xdr3.h
@@ -31,12 +31,6 @@ struct nfsd3_readdirargs {
 	__be32 *		verf;
 };
 
-struct nfsd3_commitargs {
-	struct svc_fh		fh;
-	__u64			offset;
-	__u32			count;
-};
-
 struct nfsd3_getaclargs {
 	struct svc_fh		fh;
 	__u32			mask;
@@ -105,11 +99,11 @@ struct nfsd3_pathconfres {
 static_assert(offsetof(struct nfsd3_pathconfres, xdrgen) == 0);
 
 struct nfsd3_commitres {
-	__be32			status;
-	struct svc_fh		fh;
-	__be32			verf[2];
+	struct COMMIT3res	xdrgen;
 };
 
+static_assert(offsetof(struct nfsd3_commitres, xdrgen) == 0);
+
 struct nfsd3_getaclres {
 	__be32			status;
 	struct svc_fh		fh;
@@ -121,11 +115,9 @@ struct nfsd3_getaclres {
 
 bool nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
-bool nfs3svc_decode_commitargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 
 bool nfs3svc_encode_accessres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
-bool nfs3svc_encode_commitres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 
 void nfs3svc_release_fhandle(struct svc_rqst *);
 
-- 
2.55.0

[PATCH v3 27/34] NFSD: Use xdrgen XDR functions for NFSv3 READDIR arguments

[Chuck Lever]

Replace the NFSPROC3_READDIR entry in the nfsd_procedures3 array
with an entry that dispatches the xdrgen-generated
nfs_svc_decode_READDIR3args. A wrapper structure bridges the
generated xdrgen READDIR3args type and the legacy svc_fh
representation the NFSD VFS layer still uses.

The pc_argzero field is now set to zero for the NFSv3 READDIR
procedure. The xdrgen decoders are trusted to initialize all
arguments in the argp->xdrgen field, making the early defensive
memset unnecessary. The remaining argp fields are cleared as
needed.

nfs3svc_decode_readdirargs() no longer has any callers, so it is
removed.

Signed-off-by: Chuck Lever <cel@kernel.org>
---
 fs/nfsd/nfs3proc.c | 59 +++++++++++++++++++++++++++++-----------------
 fs/nfsd/nfs3xdr.c  | 18 --------------
 fs/nfsd/xdr3.h     |  1 -
 3 files changed, 37 insertions(+), 41 deletions(-)

diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index 7a03c9ed8fbd..1764cd5e562d 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -218,6 +218,13 @@ struct COMMIT3args_wrapper {
 
 static_assert(offsetof(struct COMMIT3args_wrapper, xdrgen) == 0);
 
+struct READDIR3args_wrapper {
+	struct READDIR3args	xdrgen;
+	struct svc_fh		fh;
+};
+
+static_assert(offsetof(struct READDIR3args_wrapper, xdrgen) == 0);
+
 static int nfsd3_ftype3_to_mode(ftype3 ftype)
 {
 	switch (ftype) {
@@ -1506,28 +1513,35 @@ static void nfsd3_init_dirlist_pages(struct svc_rqst *rqstp,
 	xdr_init_encode_pages(xdr, buf);
 }
 
-/*
- * Read a portion of a directory.
+/**
+ * nfsd3_proc_readdir - READDIR: Read from directory
+ * @rqstp: RPC transaction context
+ *
+ * Return:
+ *   %rpc_success:		RPC executed successfully
+ *
+ * RPC synopsis:
+ *   READDIR3res NFSPROC3_READDIR(READDIR3args) = 16;
  */
-static __be32
-nfsd3_proc_readdir(struct svc_rqst *rqstp)
+static __be32 nfsd3_proc_readdir(struct svc_rqst *rqstp)
 {
-	struct nfsd3_readdirargs *argp = rqstp->rq_argp;
+	struct READDIR3args_wrapper *argp = rqstp->rq_argp;
 	struct nfsd3_readdirres  *resp = rqstp->rq_resp;
-	loff_t		offset;
+	loff_t offset = argp->xdrgen.cookie;
+	struct svc_fh *fhp = &argp->fh;
 
-	trace_nfsd_vfs_readdir(rqstp, &argp->fh, argp->count, argp->cookie);
+	nfsd3_fh3_to_svc_fh(fhp, &argp->xdrgen.dir);
+	trace_nfsd_vfs_readdir(rqstp, fhp, argp->xdrgen.count,
+			       argp->xdrgen.cookie);
 
-	nfsd3_init_dirlist_pages(rqstp, resp, argp->count);
-
-	fh_copy(&resp->fh, &argp->fh);
+	nfsd3_init_dirlist_pages(rqstp, resp, argp->xdrgen.count);
+	fh_copy(&resp->fh, fhp);
 	resp->common.err = nfs_ok;
 	resp->cookie_offset = 0;
 	resp->rqstp = rqstp;
-	offset = argp->cookie;
 	resp->status = nfsd_readdir(rqstp, &resp->fh, &offset,
 				    &resp->common, nfs3svc_encode_entry3);
-	memcpy(resp->verf, argp->verf, 8);
+	memcpy(resp->verf, argp->xdrgen.cookieverf, NFS3_COOKIEVERFSIZE);
 	nfs3svc_encode_cookie3(resp, offset);
 
 	/* Recycle only pages that were part of the reply */
@@ -1993,15 +2007,15 @@ static const struct svc_procedure nfsd_procedures3[22] = {
 		.pc_name	= "LINK",
 	},
 	[NFSPROC3_READDIR] = {
-		.pc_func = nfsd3_proc_readdir,
-		.pc_decode = nfs3svc_decode_readdirargs,
-		.pc_encode = nfs3svc_encode_readdirres,
-		.pc_release = nfs3svc_release_fhandle,
-		.pc_argsize = sizeof(struct nfsd3_readdirargs),
-		.pc_argzero = sizeof(struct nfsd3_readdirargs),
-		.pc_ressize = sizeof(struct nfsd3_readdirres),
-		.pc_cachetype = RC_NOCACHE,
-		.pc_name = "READDIR",
+		.pc_func	= nfsd3_proc_readdir,
+		.pc_decode	= nfs_svc_decode_READDIR3args,
+		.pc_encode	= nfs3svc_encode_readdirres,
+		.pc_release	= nfs3svc_release_fhandle,
+		.pc_argsize	= sizeof(struct READDIR3args_wrapper),
+		.pc_argzero	= 0,
+		.pc_ressize	= sizeof(struct nfsd3_readdirres),
+		.pc_cachetype	= RC_NOCACHE,
+		.pc_name	= "READDIR",
 	},
 	[NFSPROC3_READDIRPLUS] = {
 		.pc_func = nfsd3_proc_readdirplus,
@@ -2091,7 +2105,8 @@ union nfsd3_xdrstore {
 	struct RENAME3res		renameres;
 	struct LINK3args_wrapper	linkargs;
 	struct LINK3res			linkres;
-	struct nfsd3_readdirargs	readdirargs;
+	struct READDIR3args_wrapper	readdirargs;
+	struct nfsd3_readdirargs	readdirplusargs;
 	struct READLINK3res		readlinkres;
 	struct READ3res			readres;
 	struct nfsd3_writeres		writeres;
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index e93983d08aa5..0e83a2245c45 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -228,24 +228,6 @@ svcxdr_encode_post_op_attr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
  * XDR decode functions
  */
 
-bool
-nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
-{
-	struct nfsd3_readdirargs *args = rqstp->rq_argp;
-
-	if (!svcxdr_decode_nfs_fh3(xdr, &args->fh))
-		return false;
-	if (xdr_stream_decode_u64(xdr, &args->cookie) < 0)
-		return false;
-	args->verf = xdr_inline_decode(xdr, NFS3_COOKIEVERFSIZE);
-	if (!args->verf)
-		return false;
-	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
-		return false;
-
-	return true;
-}
-
 bool
 nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
 {
diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h
index e2110f9a126b..3fb4a01011ca 100644
--- a/fs/nfsd/xdr3.h
+++ b/fs/nfsd/xdr3.h
@@ -113,7 +113,6 @@ struct nfsd3_getaclres {
 	struct kstat		stat;
 };
 
-bool nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 
 bool nfs3svc_encode_accessres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
-- 
2.55.0

[PATCH v3 28/34] NFSD: Use xdrgen XDR functions for NFSv3 READDIRPLUS arguments

[Chuck Lever]

Replace the NFSPROC3_READDIRPLUS entry in the nfsd_procedures3 array
with an entry that dispatches the xdrgen-generated
nfs_svc_decode_READDIRPLUS3args. A wrapper structure bridges the
generated xdrgen READDIRPLUS3args type and the legacy svc_fh
representation the NFSD VFS layer still uses.

The pc_argzero field is now set to zero for the NFSv3 READDIRPLUS
procedure. The xdrgen decoders are trusted to initialize all
arguments in the argp->xdrgen field, making the early defensive
memset unnecessary. The remaining argp fields are cleared as
needed.

nfs3svc_decode_readdirplusargs() no longer has any callers, so it
is removed.

Signed-off-by: Chuck Lever <cel@kernel.org>
---
 fs/nfsd/nfs3proc.c | 62 +++++++++++++++++++++++++++-------------------
 fs/nfsd/nfs3xdr.c  | 26 -------------------
 fs/nfsd/xdr3.h     |  9 -------
 3 files changed, 36 insertions(+), 61 deletions(-)

diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index 1764cd5e562d..307a3b195364 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -225,6 +225,13 @@ struct READDIR3args_wrapper {
 
 static_assert(offsetof(struct READDIR3args_wrapper, xdrgen) == 0);
 
+struct READDIRPLUS3args_wrapper {
+	struct READDIRPLUS3args	xdrgen;
+	struct svc_fh		fh;
+};
+
+static_assert(offsetof(struct READDIRPLUS3args_wrapper, xdrgen) == 0);
+
 static int nfsd3_ftype3_to_mode(ftype3 ftype)
 {
 	switch (ftype) {
@@ -1551,27 +1558,32 @@ static __be32 nfsd3_proc_readdir(struct svc_rqst *rqstp)
 	return rpc_success;
 }
 
-/*
- * Read a portion of a directory, including file handles and attrs.
- * For now, we choose to ignore the dircount parameter.
+/**
+ * nfsd3_proc_readdirplus - READDIRPLUS: Extended read from directory
+ * @rqstp: RPC transaction context
+ *
+ * Return:
+ *   %rpc_success:		RPC executed successfully
+ *
+ * RPC synopsis:
+ *   READDIRPLUS3res NFSPROC3_READDIRPLUS(READDIRPLUS3args) = 17;
  */
-static __be32
-nfsd3_proc_readdirplus(struct svc_rqst *rqstp)
+static __be32 nfsd3_proc_readdirplus(struct svc_rqst *rqstp)
 {
-	struct nfsd3_readdirargs *argp = rqstp->rq_argp;
+	struct READDIRPLUS3args_wrapper *argp = rqstp->rq_argp;
 	struct nfsd3_readdirres  *resp = rqstp->rq_resp;
-	loff_t	offset;
+	loff_t offset = argp->xdrgen.cookie;
+	struct svc_fh *fhp = &argp->fh;
 
-	trace_nfsd_vfs_readdir(rqstp, &argp->fh, argp->count, argp->cookie);
+	nfsd3_fh3_to_svc_fh(fhp, &argp->xdrgen.dir);
+	trace_nfsd_vfs_readdir(rqstp, fhp, argp->xdrgen.maxcount,
+			       argp->xdrgen.cookie);
 
-	nfsd3_init_dirlist_pages(rqstp, resp, argp->count);
-
-	fh_copy(&resp->fh, &argp->fh);
+	nfsd3_init_dirlist_pages(rqstp, resp, argp->xdrgen.maxcount);
+	fh_copy(&resp->fh, fhp);
 	resp->common.err = nfs_ok;
 	resp->cookie_offset = 0;
 	resp->rqstp = rqstp;
-	offset = argp->cookie;
-
 	resp->status = fh_verify(rqstp, &resp->fh, S_IFDIR, NFSD_MAY_NOP);
 	if (resp->status != nfs_ok)
 		goto out;
@@ -1583,7 +1595,7 @@ nfsd3_proc_readdirplus(struct svc_rqst *rqstp)
 
 	resp->status = nfsd_readdir(rqstp, &resp->fh, &offset,
 				    &resp->common, nfs3svc_encode_entryplus3);
-	memcpy(resp->verf, argp->verf, 8);
+	memcpy(resp->verf, argp->xdrgen.cookieverf, NFS3_COOKIEVERFSIZE);
 	nfs3svc_encode_cookie3(resp, offset);
 
 	/* Recycle only pages that were part of the reply */
@@ -1824,8 +1836,6 @@ static __be32 nfsd3_proc_commit(struct svc_rqst *rqstp)
  * NFSv3 Server procedures.
  * Only the results of non-idempotent operations are cached.
  */
-#define nfsd3_readdirplusargs		nfsd3_readdirargs
-
 static const struct svc_procedure nfsd_procedures3[22] = {
 	[NFSPROC3_NULL] = {
 		.pc_func	= nfsd3_proc_null,
@@ -2018,15 +2028,15 @@ static const struct svc_procedure nfsd_procedures3[22] = {
 		.pc_name	= "READDIR",
 	},
 	[NFSPROC3_READDIRPLUS] = {
-		.pc_func = nfsd3_proc_readdirplus,
-		.pc_decode = nfs3svc_decode_readdirplusargs,
-		.pc_encode = nfs3svc_encode_readdirres,
-		.pc_release = nfs3svc_release_fhandle,
-		.pc_argsize = sizeof(struct nfsd3_readdirplusargs),
-		.pc_argzero = sizeof(struct nfsd3_readdirplusargs),
-		.pc_ressize = sizeof(struct nfsd3_readdirres),
-		.pc_cachetype = RC_NOCACHE,
-		.pc_name = "READDIRPLUS",
+		.pc_func	= nfsd3_proc_readdirplus,
+		.pc_decode	= nfs_svc_decode_READDIRPLUS3args,
+		.pc_encode	= nfs3svc_encode_readdirres,
+		.pc_release	= nfs3svc_release_fhandle,
+		.pc_argsize	= sizeof(struct READDIRPLUS3args_wrapper),
+		.pc_argzero	= 0,
+		.pc_ressize	= sizeof(struct nfsd3_readdirres),
+		.pc_cachetype	= RC_NOCACHE,
+		.pc_name	= "READDIRPLUS",
 	},
 	[NFSPROC3_FSSTAT] = {
 		.pc_func	= nfsd3_proc_fsstat,
@@ -2106,7 +2116,7 @@ union nfsd3_xdrstore {
 	struct LINK3args_wrapper	linkargs;
 	struct LINK3res			linkres;
 	struct READDIR3args_wrapper	readdirargs;
-	struct nfsd3_readdirargs	readdirplusargs;
+	struct READDIRPLUS3args_wrapper	readdirplusargs;
 	struct READLINK3res		readlinkres;
 	struct READ3res			readres;
 	struct nfsd3_writeres		writeres;
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index 0e83a2245c45..b1a930b857d7 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -224,32 +224,6 @@ svcxdr_encode_post_op_attr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 	return xdr_stream_encode_item_absent(xdr) > 0;
 }
 
-/*
- * XDR decode functions
- */
-
-bool
-nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
-{
-	struct nfsd3_readdirargs *args = rqstp->rq_argp;
-	u32 dircount;
-
-	if (!svcxdr_decode_nfs_fh3(xdr, &args->fh))
-		return false;
-	if (xdr_stream_decode_u64(xdr, &args->cookie) < 0)
-		return false;
-	args->verf = xdr_inline_decode(xdr, NFS3_COOKIEVERFSIZE);
-	if (!args->verf)
-		return false;
-	/* dircount is ignored */
-	if (xdr_stream_decode_u32(xdr, &dircount) < 0)
-		return false;
-	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
-		return false;
-
-	return true;
-}
-
 /*
  * XDR encode functions
  */
diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h
index 3fb4a01011ca..4c4642077342 100644
--- a/fs/nfsd/xdr3.h
+++ b/fs/nfsd/xdr3.h
@@ -24,13 +24,6 @@ struct nfsd3_accessargs {
 	__u32			access;
 };
 
-struct nfsd3_readdirargs {
-	struct svc_fh		fh;
-	__u64			cookie;
-	__u32			count;
-	__be32 *		verf;
-};
-
 struct nfsd3_getaclargs {
 	struct svc_fh		fh;
 	__u32			mask;
@@ -113,8 +106,6 @@ struct nfsd3_getaclres {
 	struct kstat		stat;
 };
 
-bool nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
-
 bool nfs3svc_encode_accessres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool nfs3svc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 
-- 
2.55.0

[PATCH v3 29/34] NFSD: Refactor NFSv3 directory cookie encoding

[Chuck Lever]

The current synopsis of nfs3svc_encode_cookie3() takes a "struct
nfsd3_readdirres" argument, which is common to the NFSv3 READDIR and
READDIRPLUS procedures.

xdrgen defines two distinct argument structures for these procedures
since they are actually two distinct procedures and have different
arguments.

With a "struct READDIR3args" and a "struct READDIRPLUS3args," the
cookie3 encoder will need generic parameter types in order to be
callable from both.

Note that NFSD can't use the xdrgen-generated cookie3 encoder. This
is because directory cookies need to point to the previous directory
entry. Space for each cookie in the send buffer is reserved when
each directory entry is encoded; when the /next/ entry is encoded,
the encoder writes its offset into that reserved space.

As a clean-up, remove "resp->cookie_offset = 0;" :

- In nfs3svc_encode_entry3() and nfs3svc_encode_entryplus3(),
  immediately after calling nfs3svc_encode_cookie3(), the code calls
  svcxdr_encode_entry3_common() which sets a new resp->cookie_offset
  value. The cookie_offset value was immediately overwritten.
- In nfsd3_proc_readdir() and nfsd3_proc_readdirplus(),
  nfs3svc_encode_cookie3() is called as the last cookie encoding,
  and no further use of cookie_offset follows.
- The out_toosmall error paths in entry encoders continue to set
  resp->cookie_offset = 0

Signed-off-by: Chuck Lever <cel@kernel.org>
---
 fs/nfsd/nfs3proc.c |  4 ++--
 fs/nfsd/nfs3xdr.c  | 22 +++++++++++-----------
 fs/nfsd/xdr3.h     |  3 ++-
 3 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index 307a3b195364..9d2fcb697e72 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -1549,7 +1549,7 @@ static __be32 nfsd3_proc_readdir(struct svc_rqst *rqstp)
 	resp->status = nfsd_readdir(rqstp, &resp->fh, &offset,
 				    &resp->common, nfs3svc_encode_entry3);
 	memcpy(resp->verf, argp->xdrgen.cookieverf, NFS3_COOKIEVERFSIZE);
-	nfs3svc_encode_cookie3(resp, offset);
+	nfs3svc_encode_cookie3(&resp->xdr, resp->cookie_offset, offset);
 
 	/* Recycle only pages that were part of the reply */
 	rqstp->rq_next_page = resp->xdr.page_ptr + 1;
@@ -1596,7 +1596,7 @@ static __be32 nfsd3_proc_readdirplus(struct svc_rqst *rqstp)
 	resp->status = nfsd_readdir(rqstp, &resp->fh, &offset,
 				    &resp->common, nfs3svc_encode_entryplus3);
 	memcpy(resp->verf, argp->xdrgen.cookieverf, NFS3_COOKIEVERFSIZE);
-	nfs3svc_encode_cookie3(resp, offset);
+	nfs3svc_encode_cookie3(&resp->xdr, resp->cookie_offset, offset);
 
 	/* Recycle only pages that were part of the reply */
 	rqstp->rq_next_page = resp->xdr.page_ptr + 1;
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index b1a930b857d7..279b19d5e3ac 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -300,22 +300,22 @@ compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
 }
 
 /**
- * nfs3svc_encode_cookie3 - Encode a directory offset cookie
- * @resp: readdir result context
- * @offset: offset cookie to encode
+ * nfs3svc_encode_cookie3 - Encode a directory cookie
+ * @xdr: stream into which to encode the cookie
+ * @pos: byte position in the stream
+ * @cookie: cookie to be encoded
  *
  * The buffer space for the offset cookie has already been reserved
  * by svcxdr_encode_entry3_common().
  */
-void nfs3svc_encode_cookie3(struct nfsd3_readdirres *resp, u64 offset)
+void nfs3svc_encode_cookie3(struct xdr_stream *xdr, unsigned int pos,
+			    u64 cookie)
 {
-	__be64 cookie = cpu_to_be64(offset);
+	__be64 wire_cookie = cpu_to_be64(cookie);
 
-	if (!resp->cookie_offset)
+	if (!pos)
 		return;
-	write_bytes_to_xdr_buf(&resp->dirlist, resp->cookie_offset, &cookie,
-			       sizeof(cookie));
-	resp->cookie_offset = 0;
+	write_bytes_to_xdr_buf(xdr->buf, pos, &wire_cookie, XDR_UNIT * 2);
 }
 
 static bool
@@ -369,7 +369,7 @@ int nfs3svc_encode_entry3(void *data, const char *name, int namlen,
 	unsigned int starting_length = resp->dirlist.len;
 
 	/* The offset cookie for the previous entry */
-	nfs3svc_encode_cookie3(resp, offset);
+	nfs3svc_encode_cookie3(&resp->xdr, resp->cookie_offset, offset);
 
 	if (!svcxdr_encode_entry3_common(resp, name, namlen, offset, ino))
 		goto out_toosmall;
@@ -444,7 +444,7 @@ int nfs3svc_encode_entryplus3(void *data, const char *name, int namlen,
 	unsigned int starting_length = resp->dirlist.len;
 
 	/* The offset cookie for the previous entry */
-	nfs3svc_encode_cookie3(resp, offset);
+	nfs3svc_encode_cookie3(&resp->xdr, resp->cookie_offset, offset);
 
 	if (!svcxdr_encode_entry3_common(resp, name, namlen, offset, ino))
 		goto out_toosmall;
diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h
index 4c4642077342..fdb2e68e16d5 100644
--- a/fs/nfsd/xdr3.h
+++ b/fs/nfsd/xdr3.h
@@ -111,7 +111,8 @@ bool nfs3svc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 
 void nfs3svc_release_fhandle(struct svc_rqst *);
 
-void nfs3svc_encode_cookie3(struct nfsd3_readdirres *resp, u64 offset);
+void nfs3svc_encode_cookie3(struct xdr_stream *xdr, unsigned int pos,
+			    u64 cookie);
 int nfs3svc_encode_entry3(void *data, const char *name, int namlen,
 			  loff_t offset, u64 ino, unsigned int d_type);
 int nfs3svc_encode_entryplus3(void *data, const char *name, int namlen,
-- 
2.55.0