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From:   "NeilBrown" <neilb@suse.de>
To:     "J.  Bruce Fields" <bfields@fieldses.org>,
        "Chuck Lever" <chuck.lever@oracle.com>
Cc:     "Christoph Hellwig" <hch@lst.de>, linux-nfs@vger.kernel.org
Subject: [PATCH 1/2 v2] NFSD: drop support for ancient filehandles
In-reply-to: <20210827151505.GA19199@lst.de>
References: <162995209561.7591.4202079352301963089@noble.neil.brown.name>,
 <20210827151505.GA19199@lst.de>
Date:   Tue, 31 Aug 2021 14:41:23 +1000
Message-id: <163038488360.7591.7865010833762169362@noble.neil.brown.name>
Precedence: bulk


Filehandles not in the "new" or "version 1" format have not been handed
out for new mounts since Linux 2.4 which was released 20 years ago.
I think it is safe to say that no such file handles are still in use,
and that we can drop support for them.

This patch also moves the nfs_fh.h (with old-format filehandle
information removed) from the include/uapi directory into fs/nfsd.  I
can find no evidence of it being used anywhere outside the kernel.
Certainly nfs-utils and wireshark do not use it.

As these declarations are no longer in 'uapi' we can use the 'u8' style
of integer type rather than '__u8'.

Signed-off-by: NeilBrown <neilb@suse.de>
---
 fs/nfsd/nfsfh.c                 | 157 +++++++++++---------------------
 fs/nfsd/nfsfh.h                 |  69 +++++++++++++-
 include/uapi/linux/nfsd/nfsfh.h | 116 -----------------------
 3 files changed, 119 insertions(+), 223 deletions(-)
 delete mode 100644 include/uapi/linux/nfsd/nfsfh.h

diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index c475d2271f9c..9194a940b23d 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -154,11 +154,12 @@ static inline __be32 check_pseudo_root(struct svc_rqst =
*rqstp,
 static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
 {
 	struct knfsd_fh	*fh =3D &fhp->fh_handle;
-	struct fid *fid =3D NULL, sfid;
+	struct fid *fid =3D NULL;
 	struct svc_export *exp;
 	struct dentry *dentry;
 	int fileid_type;
 	int data_left =3D fh->fh_size/4;
+	int len;
 	__be32 error;
=20
 	error =3D nfserr_stale;
@@ -167,48 +168,35 @@ static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp=
, struct svc_fh *fhp)
 	if (rqstp->rq_vers =3D=3D 4 && fh->fh_size =3D=3D 0)
 		return nfserr_nofilehandle;
=20
-	if (fh->fh_version =3D=3D 1) {
-		int len;
-
-		if (--data_left < 0)
-			return error;
-		if (fh->fh_auth_type !=3D 0)
-			return error;
-		len =3D key_len(fh->fh_fsid_type) / 4;
-		if (len =3D=3D 0)
-			return error;
-		if  (fh->fh_fsid_type =3D=3D FSID_MAJOR_MINOR) {
-			/* deprecated, convert to type 3 */
-			len =3D key_len(FSID_ENCODE_DEV)/4;
-			fh->fh_fsid_type =3D FSID_ENCODE_DEV;
-			/*
-			 * struct knfsd_fh uses host-endian fields, which are
-			 * sometimes used to hold net-endian values. This
-			 * confuses sparse, so we must use __force here to
-			 * keep it from complaining.
-			 */
-			fh->fh_fsid[0] =3D new_encode_dev(MKDEV(ntohl((__force __be32)fh->fh_fsid=
[0]),
-							ntohl((__force __be32)fh->fh_fsid[1])));
-			fh->fh_fsid[1] =3D fh->fh_fsid[2];
-		}
-		data_left -=3D len;
-		if (data_left < 0)
-			return error;
-		exp =3D rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_fsid);
-		fid =3D (struct fid *)(fh->fh_fsid + len);
-	} else {
-		__u32 tfh[2];
-		dev_t xdev;
-		ino_t xino;
-
-		if (fh->fh_size !=3D NFS_FHSIZE)
-			return error;
-		/* assume old filehandle format */
-		xdev =3D old_decode_dev(fh->ofh_xdev);
-		xino =3D u32_to_ino_t(fh->ofh_xino);
-		mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
-		exp =3D rqst_exp_find(rqstp, FSID_DEV, tfh);
+	if (fh->fh_version !=3D 1)
+		return error;
+
+	if (--data_left < 0)
+		return error;
+	if (fh->fh_auth_type !=3D 0)
+		return error;
+	len =3D key_len(fh->fh_fsid_type) / 4;
+	if (len =3D=3D 0)
+		return error;
+	if (fh->fh_fsid_type =3D=3D FSID_MAJOR_MINOR) {
+		/* deprecated, convert to type 3 */
+		len =3D key_len(FSID_ENCODE_DEV)/4;
+		fh->fh_fsid_type =3D FSID_ENCODE_DEV;
+		/*
+		 * struct knfsd_fh uses host-endian fields, which are
+		 * sometimes used to hold net-endian values. This
+		 * confuses sparse, so we must use __force here to
+		 * keep it from complaining.
+		 */
+		fh->fh_fsid[0] =3D new_encode_dev(MKDEV(ntohl((__force __be32)fh->fh_fsid[=
0]),
+						      ntohl((__force __be32)fh->fh_fsid[1])));
+		fh->fh_fsid[1] =3D fh->fh_fsid[2];
 	}
+	data_left -=3D len;
+	if (data_left < 0)
+		return error;
+	exp =3D rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_fsid);
+	fid =3D (struct fid *)(fh->fh_fsid + len);
=20
 	error =3D nfserr_stale;
 	if (IS_ERR(exp)) {
@@ -253,18 +241,7 @@ static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp,=
 struct svc_fh *fhp)
 	if (rqstp->rq_vers > 2)
 		error =3D nfserr_badhandle;
=20
-	if (fh->fh_version !=3D 1) {
-		sfid.i32.ino =3D fh->ofh_ino;
-		sfid.i32.gen =3D fh->ofh_generation;
-		sfid.i32.parent_ino =3D fh->ofh_dirino;
-		fid =3D &sfid;
-		data_left =3D 3;
-		if (fh->ofh_dirino =3D=3D 0)
-			fileid_type =3D FILEID_INO32_GEN;
-		else
-			fileid_type =3D FILEID_INO32_GEN_PARENT;
-	} else
-		fileid_type =3D fh->fh_fileid_type;
+	fileid_type =3D fh->fh_fileid_type;
=20
 	if (fileid_type =3D=3D FILEID_ROOT)
 		dentry =3D dget(exp->ex_path.dentry);
@@ -452,20 +429,6 @@ static void _fh_update(struct svc_fh *fhp, struct svc_ex=
port *exp,
 	}
 }
=20
-/*
- * for composing old style file handles
- */
-static inline void _fh_update_old(struct dentry *dentry,
-				  struct svc_export *exp,
-				  struct knfsd_fh *fh)
-{
-	fh->ofh_ino =3D ino_t_to_u32(d_inode(dentry)->i_ino);
-	fh->ofh_generation =3D d_inode(dentry)->i_generation;
-	if (d_is_dir(dentry) ||
-	    (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
-		fh->ofh_dirino =3D 0;
-}
-
 static bool is_root_export(struct svc_export *exp)
 {
 	return exp->ex_path.dentry =3D=3D exp->ex_path.dentry->d_sb->s_root;
@@ -600,35 +563,21 @@ fh_compose(struct svc_fh *fhp, struct svc_export *exp, =
struct dentry *dentry,
 	fhp->fh_dentry =3D dget(dentry); /* our internal copy */
 	fhp->fh_export =3D exp_get(exp);
=20
-	if (fhp->fh_handle.fh_version =3D=3D 0xca) {
-		/* old style filehandle please */
-		memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
-		fhp->fh_handle.fh_size =3D NFS_FHSIZE;
-		fhp->fh_handle.ofh_dcookie =3D 0xfeebbaca;
-		fhp->fh_handle.ofh_dev =3D  old_encode_dev(ex_dev);
-		fhp->fh_handle.ofh_xdev =3D fhp->fh_handle.ofh_dev;
-		fhp->fh_handle.ofh_xino =3D
-			ino_t_to_u32(d_inode(exp->ex_path.dentry)->i_ino);
-		fhp->fh_handle.ofh_dirino =3D ino_t_to_u32(parent_ino(dentry));
-		if (inode)
-			_fh_update_old(dentry, exp, &fhp->fh_handle);
-	} else {
-		fhp->fh_handle.fh_size =3D
-			key_len(fhp->fh_handle.fh_fsid_type) + 4;
-		fhp->fh_handle.fh_auth_type =3D 0;
-
-		mk_fsid(fhp->fh_handle.fh_fsid_type,
-			fhp->fh_handle.fh_fsid,
-			ex_dev,
-			d_inode(exp->ex_path.dentry)->i_ino,
-			exp->ex_fsid, exp->ex_uuid);
-
-		if (inode)
-			_fh_update(fhp, exp, dentry);
-		if (fhp->fh_handle.fh_fileid_type =3D=3D FILEID_INVALID) {
-			fh_put(fhp);
-			return nfserr_opnotsupp;
-		}
+	fhp->fh_handle.fh_size =3D
+		key_len(fhp->fh_handle.fh_fsid_type) + 4;
+	fhp->fh_handle.fh_auth_type =3D 0;
+
+	mk_fsid(fhp->fh_handle.fh_fsid_type,
+		fhp->fh_handle.fh_fsid,
+		ex_dev,
+		d_inode(exp->ex_path.dentry)->i_ino,
+		exp->ex_fsid, exp->ex_uuid);
+
+	if (inode)
+		_fh_update(fhp, exp, dentry);
+	if (fhp->fh_handle.fh_fileid_type =3D=3D FILEID_INVALID) {
+		fh_put(fhp);
+		return nfserr_opnotsupp;
 	}
=20
 	return 0;
@@ -649,16 +598,12 @@ fh_update(struct svc_fh *fhp)
 	dentry =3D fhp->fh_dentry;
 	if (d_really_is_negative(dentry))
 		goto out_negative;
-	if (fhp->fh_handle.fh_version !=3D 1) {
-		_fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
-	} else {
-		if (fhp->fh_handle.fh_fileid_type !=3D FILEID_ROOT)
-			return 0;
+	if (fhp->fh_handle.fh_fileid_type !=3D FILEID_ROOT)
+		return 0;
=20
-		_fh_update(fhp, fhp->fh_export, dentry);
-		if (fhp->fh_handle.fh_fileid_type =3D=3D FILEID_INVALID)
-			return nfserr_opnotsupp;
-	}
+	_fh_update(fhp, fhp->fh_export, dentry);
+	if (fhp->fh_handle.fh_fileid_type =3D=3D FILEID_INVALID)
+		return nfserr_opnotsupp;
 	return 0;
 out_bad:
 	printk(KERN_ERR "fh_update: fh not verified!\n");
diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h
index 6106697adc04..17fc6f57d1bb 100644
--- a/fs/nfsd/nfsfh.h
+++ b/fs/nfsd/nfsfh.h
@@ -10,9 +10,76 @@
=20
 #include <linux/crc32.h>
 #include <linux/sunrpc/svc.h>
-#include <uapi/linux/nfsd/nfsfh.h>
 #include <linux/iversion.h>
 #include <linux/exportfs.h>
+#include <linux/nfs4.h>
+
+/*
+ * The file handle starts with a sequence of four-byte words.
+ * The first word contains a version number (1) and three descriptor bytes
+ * that tell how the remaining 3 variable length fields should be handled.
+ * These three bytes are auth_type, fsid_type and fileid_type.
+ *
+ * All four-byte values are in host-byte-order.
+ *
+ * The auth_type field is deprecated and must be set to 0.
+ *
+ * The fsid_type identifies how the filesystem (or export point) is
+ *    encoded.
+ *  Current values:
+ *     0  - 4 byte device id (ms-2-bytes major, ls-2-bytes minor), 4byte ino=
de number
+ *        NOTE: we cannot use the kdev_t device id value, because kdev_t.h
+ *              says we mustn't.  We must break it up and reassemble.
+ *     1  - 4 byte user specified identifier
+ *     2  - 4 byte major, 4 byte minor, 4 byte inode number - DEPRECATED
+ *     3  - 4 byte device id, encoded for user-space, 4 byte inode number
+ *     4  - 4 byte inode number and 4 byte uuid
+ *     5  - 8 byte uuid
+ *     6  - 16 byte uuid
+ *     7  - 8 byte inode number and 16 byte uuid
+ *
+ * The fileid_type identifies how the file within the filesystem is encoded.
+ *   The values for this field are filesystem specific, exccept that
+ *   filesystems must not use the values '0' or '0xff'. 'See enum fid_type'
+ *   in include/linux/exportfs.h for currently registered values.
+ */
+struct nfs_fhbase_new {
+	union {
+		struct {
+			u8		fb_version_aux;	/* =3D=3D 1, even =3D> nfs_fhbase_old */
+			u8		fb_auth_type_aux;
+			u8		fb_fsid_type_aux;
+			u8		fb_fileid_type_aux;
+			u32		fb_auth[1];
+		/*	u32		fb_fsid[0]; floating */
+		/*	u32		fb_fileid[0]; floating */
+		};
+		struct {
+			u8		fb_version;	/* =3D=3D 1, even =3D> nfs_fhbase_old */
+			u8		fb_auth_type;
+			u8		fb_fsid_type;
+			u8		fb_fileid_type;
+			u32		fb_auth_flex[]; /* flexible-array member */
+		};
+	};
+};
+
+struct knfsd_fh {
+	unsigned int	fh_size;	/* significant for NFSv3.
+					 * Points to the current size while building
+					 * a new file handle
+					 */
+	union {
+		u32			fh_pad[NFS4_FHSIZE/4];
+		struct nfs_fhbase_new	fh_new;
+	} fh_base;
+};
+
+#define	fh_version		fh_base.fh_new.fb_version
+#define	fh_fsid_type		fh_base.fh_new.fb_fsid_type
+#define	fh_auth_type		fh_base.fh_new.fb_auth_type
+#define	fh_fileid_type		fh_base.fh_new.fb_fileid_type
+#define	fh_fsid			fh_base.fh_new.fb_auth_flex
=20
 static inline __u32 ino_t_to_u32(ino_t ino)
 {
diff --git a/include/uapi/linux/nfsd/nfsfh.h b/include/uapi/linux/nfsd/nfsfh.h
deleted file mode 100644
index 427294dd56a1..000000000000
--- a/include/uapi/linux/nfsd/nfsfh.h
+++ /dev/null
@@ -1,116 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/*
- * This file describes the layout of the file handles as passed
- * over the wire.
- *
- * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
- */
-
-#ifndef _UAPI_LINUX_NFSD_FH_H
-#define _UAPI_LINUX_NFSD_FH_H
-
-#include <linux/types.h>
-#include <linux/nfs.h>
-#include <linux/nfs2.h>
-#include <linux/nfs3.h>
-#include <linux/nfs4.h>
-
-/*
- * This is the old "dentry style" Linux NFSv2 file handle.
- *
- * The xino and xdev fields are currently used to transport the
- * ino/dev of the exported inode.
- */
-struct nfs_fhbase_old {
-	__u32		fb_dcookie;	/* dentry cookie - always 0xfeebbaca */
-	__u32		fb_ino;		/* our inode number */
-	__u32		fb_dirino;	/* dir inode number, 0 for directories */
-	__u32		fb_dev;		/* our device */
-	__u32		fb_xdev;
-	__u32		fb_xino;
-	__u32		fb_generation;
-};
-
-/*
- * This is the new flexible, extensible style NFSv2/v3/v4 file handle.
- * by Neil Brown <neilb@cse.unsw.edu.au> - March 2000
- *
- * The file handle starts with a sequence of four-byte words.
- * The first word contains a version number (1) and three descriptor bytes
- * that tell how the remaining 3 variable length fields should be handled.
- * These three bytes are auth_type, fsid_type and fileid_type.
- *
- * All four-byte values are in host-byte-order.
- *
- * The auth_type field is deprecated and must be set to 0.
- *
- * The fsid_type identifies how the filesystem (or export point) is
- *    encoded.
- *  Current values:
- *     0  - 4 byte device id (ms-2-bytes major, ls-2-bytes minor), 4byte ino=
de number
- *        NOTE: we cannot use the kdev_t device id value, because kdev_t.h
- *              says we mustn't.  We must break it up and reassemble.
- *     1  - 4 byte user specified identifier
- *     2  - 4 byte major, 4 byte minor, 4 byte inode number - DEPRECATED
- *     3  - 4 byte device id, encoded for user-space, 4 byte inode number
- *     4  - 4 byte inode number and 4 byte uuid
- *     5  - 8 byte uuid
- *     6  - 16 byte uuid
- *     7  - 8 byte inode number and 16 byte uuid
- *
- * The fileid_type identified how the file within the filesystem is encoded.
- *   The values for this field are filesystem specific, exccept that
- *   filesystems must not use the values '0' or '0xff'. 'See enum fid_type'
- *   in include/linux/exportfs.h for currently registered values.
- */
-struct nfs_fhbase_new {
-	union {
-		struct {
-			__u8		fb_version_aux;	/* =3D=3D 1, even =3D> nfs_fhbase_old */
-			__u8		fb_auth_type_aux;
-			__u8		fb_fsid_type_aux;
-			__u8		fb_fileid_type_aux;
-			__u32		fb_auth[1];
-			/*	__u32		fb_fsid[0]; floating */
-			/*	__u32		fb_fileid[0]; floating */
-		};
-		struct {
-			__u8		fb_version;	/* =3D=3D 1, even =3D> nfs_fhbase_old */
-			__u8		fb_auth_type;
-			__u8		fb_fsid_type;
-			__u8		fb_fileid_type;
-			__u32		fb_auth_flex[]; /* flexible-array member */
-		};
-	};
-};
-
-struct knfsd_fh {
-	unsigned int	fh_size;	/* significant for NFSv3.
-					 * Points to the current size while building
-					 * a new file handle
-					 */
-	union {
-		struct nfs_fhbase_old	fh_old;
-		__u32			fh_pad[NFS4_FHSIZE/4];
-		struct nfs_fhbase_new	fh_new;
-	} fh_base;
-};
-
-#define ofh_dcookie		fh_base.fh_old.fb_dcookie
-#define ofh_ino			fh_base.fh_old.fb_ino
-#define ofh_dirino		fh_base.fh_old.fb_dirino
-#define ofh_dev			fh_base.fh_old.fb_dev
-#define ofh_xdev		fh_base.fh_old.fb_xdev
-#define ofh_xino		fh_base.fh_old.fb_xino
-#define ofh_generation		fh_base.fh_old.fb_generation
-
-#define	fh_version		fh_base.fh_new.fb_version
-#define	fh_fsid_type		fh_base.fh_new.fb_fsid_type
-#define	fh_auth_type		fh_base.fh_new.fb_auth_type
-#define	fh_fileid_type		fh_base.fh_new.fb_fileid_type
-#define	fh_fsid			fh_base.fh_new.fb_auth_flex
-
-/* Do not use, provided for userspace compatiblity. */
-#define	fh_auth			fh_base.fh_new.fb_auth
-
-#endif /* _UAPI_LINUX_NFSD_FH_H */
--=20
2.32.0