1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 /* 3 * This file describes the layout of the file handles as passed 4 * over the wire. 5 * 6 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de> 7 */ 8 9 #ifndef _UAPI_LINUX_NFSD_FH_H 10 #define _UAPI_LINUX_NFSD_FH_H 11 12 #include <linux/types.h> 13 #include <linux/nfs.h> 14 #include <linux/nfs2.h> 15 #include <linux/nfs3.h> 16 #include <linux/nfs4.h> 17 18 /* 19 * This is the old "dentry style" Linux NFSv2 file handle. 20 * 21 * The xino and xdev fields are currently used to transport the 22 * ino/dev of the exported inode. 23 */ 24 struct nfs_fhbase_old { 25 __u32 fb_dcookie; /* dentry cookie - always 0xfeebbaca */ 26 __u32 fb_ino; /* our inode number */ 27 __u32 fb_dirino; /* dir inode number, 0 for directories */ 28 __u32 fb_dev; /* our device */ 29 __u32 fb_xdev; 30 __u32 fb_xino; 31 __u32 fb_generation; 32 }; 33 34 /* 35 * This is the new flexible, extensible style NFSv2/v3/v4 file handle. 36 * 37 * The file handle starts with a sequence of four-byte words. 38 * The first word contains a version number (1) and three descriptor bytes 39 * that tell how the remaining 3 variable length fields should be handled. 40 * These three bytes are auth_type, fsid_type and fileid_type. 41 * 42 * All four-byte values are in host-byte-order. 43 * 44 * The auth_type field is deprecated and must be set to 0. 45 * 46 * The fsid_type identifies how the filesystem (or export point) is 47 * encoded. 48 * Current values: 49 * 0 - 4 byte device id (ms-2-bytes major, ls-2-bytes minor), 4byte inode number 50 * NOTE: we cannot use the kdev_t device id value, because kdev_t.h 51 * says we mustn't. We must break it up and reassemble. 52 * 1 - 4 byte user specified identifier 53 * 2 - 4 byte major, 4 byte minor, 4 byte inode number - DEPRECATED 54 * 3 - 4 byte device id, encoded for user-space, 4 byte inode number 55 * 4 - 4 byte inode number and 4 byte uuid 56 * 5 - 8 byte uuid 57 * 6 - 16 byte uuid 58 * 7 - 8 byte inode number and 16 byte uuid 59 * 60 * The fileid_type identified how the file within the filesystem is encoded. 61 * The values for this field are filesystem specific, exccept that 62 * filesystems must not use the values '0' or '0xff'. 'See enum fid_type' 63 * in include/linux/exportfs.h for currently registered values. 64 */ 65 struct nfs_fhbase_new { 66 union { 67 struct { 68 __u8 fb_version_aux; /* == 1, even => nfs_fhbase_old */ 69 __u8 fb_auth_type_aux; 70 __u8 fb_fsid_type_aux; 71 __u8 fb_fileid_type_aux; 72 __u32 fb_auth[1]; 73 /* __u32 fb_fsid[0]; floating */ 74 /* __u32 fb_fileid[0]; floating */ 75 }; 76 struct { 77 __u8 fb_version; /* == 1, even => nfs_fhbase_old */ 78 __u8 fb_auth_type; 79 __u8 fb_fsid_type; 80 __u8 fb_fileid_type; 81 __u32 fb_auth_flex[]; /* flexible-array member */ 82 }; 83 }; 84 }; 85 86 struct knfsd_fh { 87 unsigned int fh_size; /* significant for NFSv3. 88 * Points to the current size while building 89 * a new file handle 90 */ 91 union { 92 struct nfs_fhbase_old fh_old; 93 __u32 fh_pad[NFS4_FHSIZE/4]; 94 struct nfs_fhbase_new fh_new; 95 } fh_base; 96 }; 97 98 #define ofh_dcookie fh_base.fh_old.fb_dcookie 99 #define ofh_ino fh_base.fh_old.fb_ino 100 #define ofh_dirino fh_base.fh_old.fb_dirino 101 #define ofh_dev fh_base.fh_old.fb_dev 102 #define ofh_xdev fh_base.fh_old.fb_xdev 103 #define ofh_xino fh_base.fh_old.fb_xino 104 #define ofh_generation fh_base.fh_old.fb_generation 105 106 #define fh_version fh_base.fh_new.fb_version 107 #define fh_fsid_type fh_base.fh_new.fb_fsid_type 108 #define fh_auth_type fh_base.fh_new.fb_auth_type 109 #define fh_fileid_type fh_base.fh_new.fb_fileid_type 110 #define fh_fsid fh_base.fh_new.fb_auth_flex 111 112 /* Do not use, provided for userspace compatiblity. */ 113 #define fh_auth fh_base.fh_new.fb_auth 114 115 #endif /* _UAPI_LINUX_NFSD_FH_H */ 116