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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
4 *
5 * This file describes the layout of the file handles as passed
6 * over the wire.
7 */
8#ifndef _LINUX_NFSD_NFSFH_H
9#define _LINUX_NFSD_NFSFH_H
10
11#include <linux/crc32.h>
12#include <linux/sunrpc/svc.h>
13#include <linux/iversion.h>
14#include <linux/exportfs.h>
15#include <linux/nfs4.h>
16
17/*
18 * The file handle starts with a sequence of four-byte words.
19 * The first word contains a version number (1) and three descriptor bytes
20 * that tell how the remaining 3 variable length fields should be handled.
21 * These three bytes are auth_type, fsid_type and fileid_type.
22 *
23 * All four-byte values are in host-byte-order.
24 *
25 * The auth_type field is deprecated and must be set to 0.
26 *
27 * The fsid_type identifies how the filesystem (or export point) is
28 * encoded.
29 * Current values:
30 * 0 - 4 byte device id (ms-2-bytes major, ls-2-bytes minor), 4byte inode number
31 * NOTE: we cannot use the kdev_t device id value, because kdev_t.h
32 * says we mustn't. We must break it up and reassemble.
33 * 1 - 4 byte user specified identifier
34 * 2 - 4 byte major, 4 byte minor, 4 byte inode number - DEPRECATED
35 * 3 - 4 byte device id, encoded for user-space, 4 byte inode number
36 * 4 - 4 byte inode number and 4 byte uuid
37 * 5 - 8 byte uuid
38 * 6 - 16 byte uuid
39 * 7 - 8 byte inode number and 16 byte uuid
40 *
41 * The fileid_type identifies how the file within the filesystem is encoded.
42 * The values for this field are filesystem specific, exccept that
43 * filesystems must not use the values '0' or '0xff'. 'See enum fid_type'
44 * in include/linux/exportfs.h for currently registered values.
45 */
46
47struct knfsd_fh {
48 unsigned int fh_size; /*
49 * Points to the current size while
50 * building a new file handle.
51 */
52 union {
53 char fh_raw[NFS4_FHSIZE];
54 struct {
55 u8 fh_version; /* == 1 */
56 u8 fh_auth_type; /* deprecated */
57 u8 fh_fsid_type;
58 u8 fh_fileid_type;
59 u32 fh_fsid[]; /* flexible-array member */
60 };
61 };
62};
63
64static inline __u32 ino_t_to_u32(ino_t ino)
65{
66 return (__u32) ino;
67}
68
69static inline ino_t u32_to_ino_t(__u32 uino)
70{
71 return (ino_t) uino;
72}
73
74/*
75 * This is the internal representation of an NFS handle used in knfsd.
76 * pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
77 */
78typedef struct svc_fh {
79 struct knfsd_fh fh_handle; /* FH data */
80 int fh_maxsize; /* max size for fh_handle */
81 struct dentry * fh_dentry; /* validated dentry */
82 struct svc_export * fh_export; /* export pointer */
83
84 bool fh_want_write; /* remount protection taken */
85 bool fh_no_wcc; /* no wcc data needed */
86 bool fh_no_atomic_attr;
87 /*
88 * wcc data is not atomic with
89 * operation
90 */
91 int fh_flags; /* FH flags */
92 bool fh_post_saved; /* post-op attrs saved */
93 bool fh_pre_saved; /* pre-op attrs saved */
94
95 /* Pre-op attributes saved when inode is locked */
96 __u64 fh_pre_size; /* size before operation */
97 struct timespec64 fh_pre_mtime; /* mtime before oper */
98 struct timespec64 fh_pre_ctime; /* ctime before oper */
99 /*
100 * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode)
101 * to find out if it is valid.
102 */
103 u64 fh_pre_change;
104
105 /* Post-op attributes saved in fh_fill_post_attrs() */
106 struct kstat fh_post_attr; /* full attrs after operation */
107 u64 fh_post_change; /* nfsv4 change; see above */
108} svc_fh;
109#define NFSD4_FH_FOREIGN (1<<0)
110#define SET_FH_FLAG(c, f) ((c)->fh_flags |= (f))
111#define HAS_FH_FLAG(c, f) ((c)->fh_flags & (f))
112
113enum nfsd_fsid {
114 FSID_DEV = 0,
115 FSID_NUM,
116 FSID_MAJOR_MINOR,
117 FSID_ENCODE_DEV,
118 FSID_UUID4_INUM,
119 FSID_UUID8,
120 FSID_UUID16,
121 FSID_UUID16_INUM,
122};
123
124enum fsid_source {
125 FSIDSOURCE_DEV,
126 FSIDSOURCE_FSID,
127 FSIDSOURCE_UUID,
128};
129extern enum fsid_source fsid_source(const struct svc_fh *fhp);
130
131
132/*
133 * This might look a little large to "inline" but in all calls except
134 * one, 'vers' is constant so moste of the function disappears.
135 *
136 * In some cases the values are considered to be host endian and in
137 * others, net endian. fsidv is always considered to be u32 as the
138 * callers don't know which it will be. So we must use __force to keep
139 * sparse from complaining. Since these values are opaque to the
140 * client, that shouldn't be a problem.
141 */
142static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
143 u32 fsid, unsigned char *uuid)
144{
145 u32 *up;
146 switch(vers) {
147 case FSID_DEV:
148 fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) |
149 MINOR(dev));
150 fsidv[1] = ino_t_to_u32(ino);
151 break;
152 case FSID_NUM:
153 fsidv[0] = fsid;
154 break;
155 case FSID_MAJOR_MINOR:
156 fsidv[0] = (__force __u32)htonl(MAJOR(dev));
157 fsidv[1] = (__force __u32)htonl(MINOR(dev));
158 fsidv[2] = ino_t_to_u32(ino);
159 break;
160
161 case FSID_ENCODE_DEV:
162 fsidv[0] = new_encode_dev(dev);
163 fsidv[1] = ino_t_to_u32(ino);
164 break;
165
166 case FSID_UUID4_INUM:
167 /* 4 byte fsid and inode number */
168 up = (u32*)uuid;
169 fsidv[0] = ino_t_to_u32(ino);
170 fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
171 break;
172
173 case FSID_UUID8:
174 /* 8 byte fsid */
175 up = (u32*)uuid;
176 fsidv[0] = up[0] ^ up[2];
177 fsidv[1] = up[1] ^ up[3];
178 break;
179
180 case FSID_UUID16:
181 /* 16 byte fsid - NFSv3+ only */
182 memcpy(fsidv, uuid, 16);
183 break;
184
185 case FSID_UUID16_INUM:
186 /* 8 byte inode and 16 byte fsid */
187 *(u64*)fsidv = (u64)ino;
188 memcpy(fsidv+2, uuid, 16);
189 break;
190 default: BUG();
191 }
192}
193
194static inline int key_len(int type)
195{
196 switch(type) {
197 case FSID_DEV: return 8;
198 case FSID_NUM: return 4;
199 case FSID_MAJOR_MINOR: return 12;
200 case FSID_ENCODE_DEV: return 8;
201 case FSID_UUID4_INUM: return 8;
202 case FSID_UUID8: return 8;
203 case FSID_UUID16: return 16;
204 case FSID_UUID16_INUM: return 24;
205 default: return 0;
206 }
207}
208
209/*
210 * Shorthand for dprintk()'s
211 */
212extern char * SVCFH_fmt(struct svc_fh *fhp);
213
214/*
215 * Function prototypes
216 */
217__be32 fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int);
218__be32 fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
219__be32 fh_update(struct svc_fh *);
220void fh_put(struct svc_fh *);
221
222static __inline__ struct svc_fh *
223fh_copy(struct svc_fh *dst, const struct svc_fh *src)
224{
225 WARN_ON(src->fh_dentry);
226
227 *dst = *src;
228 return dst;
229}
230
231static inline void
232fh_copy_shallow(struct knfsd_fh *dst, const struct knfsd_fh *src)
233{
234 dst->fh_size = src->fh_size;
235 memcpy(&dst->fh_raw, &src->fh_raw, src->fh_size);
236}
237
238static __inline__ struct svc_fh *
239fh_init(struct svc_fh *fhp, int maxsize)
240{
241 memset(fhp, 0, sizeof(*fhp));
242 fhp->fh_maxsize = maxsize;
243 return fhp;
244}
245
246static inline bool fh_match(const struct knfsd_fh *fh1,
247 const struct knfsd_fh *fh2)
248{
249 if (fh1->fh_size != fh2->fh_size)
250 return false;
251 if (memcmp(fh1->fh_raw, fh2->fh_raw, fh1->fh_size) != 0)
252 return false;
253 return true;
254}
255
256static inline bool fh_fsid_match(const struct knfsd_fh *fh1,
257 const struct knfsd_fh *fh2)
258{
259 if (fh1->fh_fsid_type != fh2->fh_fsid_type)
260 return false;
261 if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0)
262 return false;
263 return true;
264}
265
266#ifdef CONFIG_CRC32
267/**
268 * knfsd_fh_hash - calculate the crc32 hash for the filehandle
269 * @fh - pointer to filehandle
270 *
271 * returns a crc32 hash for the filehandle that is compatible with
272 * the one displayed by "wireshark".
273 */
274static inline u32 knfsd_fh_hash(const struct knfsd_fh *fh)
275{
276 return ~crc32_le(0xFFFFFFFF, fh->fh_raw, fh->fh_size);
277}
278#else
279static inline u32 knfsd_fh_hash(const struct knfsd_fh *fh)
280{
281 return 0;
282}
283#endif
284
285/**
286 * fh_clear_pre_post_attrs - Reset pre/post attributes
287 * @fhp: file handle to be updated
288 *
289 */
290static inline void fh_clear_pre_post_attrs(struct svc_fh *fhp)
291{
292 fhp->fh_post_saved = false;
293 fhp->fh_pre_saved = false;
294}
295
296u64 nfsd4_change_attribute(const struct kstat *stat,
297 const struct inode *inode);
298__be32 __must_check fh_fill_pre_attrs(struct svc_fh *fhp);
299__be32 fh_fill_post_attrs(struct svc_fh *fhp);
300__be32 __must_check fh_fill_both_attrs(struct svc_fh *fhp);
301#endif /* _LINUX_NFSD_NFSFH_H */
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
4 *
5 * This file describes the layout of the file handles as passed
6 * over the wire.
7 */
8#ifndef _LINUX_NFSD_NFSFH_H
9#define _LINUX_NFSD_NFSFH_H
10
11#include <linux/crc32.h>
12#include <linux/sunrpc/svc.h>
13#include <uapi/linux/nfsd/nfsfh.h>
14#include <linux/iversion.h>
15#include <linux/exportfs.h>
16
17static inline __u32 ino_t_to_u32(ino_t ino)
18{
19 return (__u32) ino;
20}
21
22static inline ino_t u32_to_ino_t(__u32 uino)
23{
24 return (ino_t) uino;
25}
26
27/*
28 * This is the internal representation of an NFS handle used in knfsd.
29 * pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
30 */
31typedef struct svc_fh {
32 struct knfsd_fh fh_handle; /* FH data */
33 int fh_maxsize; /* max size for fh_handle */
34 struct dentry * fh_dentry; /* validated dentry */
35 struct svc_export * fh_export; /* export pointer */
36
37 bool fh_locked; /* inode locked by us */
38 bool fh_want_write; /* remount protection taken */
39 bool fh_no_wcc; /* no wcc data needed */
40 bool fh_no_atomic_attr;
41 /*
42 * wcc data is not atomic with
43 * operation
44 */
45 int fh_flags; /* FH flags */
46#ifdef CONFIG_NFSD_V3
47 bool fh_post_saved; /* post-op attrs saved */
48 bool fh_pre_saved; /* pre-op attrs saved */
49
50 /* Pre-op attributes saved during fh_lock */
51 __u64 fh_pre_size; /* size before operation */
52 struct timespec64 fh_pre_mtime; /* mtime before oper */
53 struct timespec64 fh_pre_ctime; /* ctime before oper */
54 /*
55 * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode)
56 * to find out if it is valid.
57 */
58 u64 fh_pre_change;
59
60 /* Post-op attributes saved in fh_unlock */
61 struct kstat fh_post_attr; /* full attrs after operation */
62 u64 fh_post_change; /* nfsv4 change; see above */
63#endif /* CONFIG_NFSD_V3 */
64} svc_fh;
65#define NFSD4_FH_FOREIGN (1<<0)
66#define SET_FH_FLAG(c, f) ((c)->fh_flags |= (f))
67#define HAS_FH_FLAG(c, f) ((c)->fh_flags & (f))
68
69enum nfsd_fsid {
70 FSID_DEV = 0,
71 FSID_NUM,
72 FSID_MAJOR_MINOR,
73 FSID_ENCODE_DEV,
74 FSID_UUID4_INUM,
75 FSID_UUID8,
76 FSID_UUID16,
77 FSID_UUID16_INUM,
78};
79
80enum fsid_source {
81 FSIDSOURCE_DEV,
82 FSIDSOURCE_FSID,
83 FSIDSOURCE_UUID,
84};
85extern enum fsid_source fsid_source(const struct svc_fh *fhp);
86
87
88/*
89 * This might look a little large to "inline" but in all calls except
90 * one, 'vers' is constant so moste of the function disappears.
91 *
92 * In some cases the values are considered to be host endian and in
93 * others, net endian. fsidv is always considered to be u32 as the
94 * callers don't know which it will be. So we must use __force to keep
95 * sparse from complaining. Since these values are opaque to the
96 * client, that shouldn't be a problem.
97 */
98static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
99 u32 fsid, unsigned char *uuid)
100{
101 u32 *up;
102 switch(vers) {
103 case FSID_DEV:
104 fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) |
105 MINOR(dev));
106 fsidv[1] = ino_t_to_u32(ino);
107 break;
108 case FSID_NUM:
109 fsidv[0] = fsid;
110 break;
111 case FSID_MAJOR_MINOR:
112 fsidv[0] = (__force __u32)htonl(MAJOR(dev));
113 fsidv[1] = (__force __u32)htonl(MINOR(dev));
114 fsidv[2] = ino_t_to_u32(ino);
115 break;
116
117 case FSID_ENCODE_DEV:
118 fsidv[0] = new_encode_dev(dev);
119 fsidv[1] = ino_t_to_u32(ino);
120 break;
121
122 case FSID_UUID4_INUM:
123 /* 4 byte fsid and inode number */
124 up = (u32*)uuid;
125 fsidv[0] = ino_t_to_u32(ino);
126 fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
127 break;
128
129 case FSID_UUID8:
130 /* 8 byte fsid */
131 up = (u32*)uuid;
132 fsidv[0] = up[0] ^ up[2];
133 fsidv[1] = up[1] ^ up[3];
134 break;
135
136 case FSID_UUID16:
137 /* 16 byte fsid - NFSv3+ only */
138 memcpy(fsidv, uuid, 16);
139 break;
140
141 case FSID_UUID16_INUM:
142 /* 8 byte inode and 16 byte fsid */
143 *(u64*)fsidv = (u64)ino;
144 memcpy(fsidv+2, uuid, 16);
145 break;
146 default: BUG();
147 }
148}
149
150static inline int key_len(int type)
151{
152 switch(type) {
153 case FSID_DEV: return 8;
154 case FSID_NUM: return 4;
155 case FSID_MAJOR_MINOR: return 12;
156 case FSID_ENCODE_DEV: return 8;
157 case FSID_UUID4_INUM: return 8;
158 case FSID_UUID8: return 8;
159 case FSID_UUID16: return 16;
160 case FSID_UUID16_INUM: return 24;
161 default: return 0;
162 }
163}
164
165/*
166 * Shorthand for dprintk()'s
167 */
168extern char * SVCFH_fmt(struct svc_fh *fhp);
169
170/*
171 * Function prototypes
172 */
173__be32 fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int);
174__be32 fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
175__be32 fh_update(struct svc_fh *);
176void fh_put(struct svc_fh *);
177
178static __inline__ struct svc_fh *
179fh_copy(struct svc_fh *dst, struct svc_fh *src)
180{
181 WARN_ON(src->fh_dentry || src->fh_locked);
182
183 *dst = *src;
184 return dst;
185}
186
187static inline void
188fh_copy_shallow(struct knfsd_fh *dst, struct knfsd_fh *src)
189{
190 dst->fh_size = src->fh_size;
191 memcpy(&dst->fh_base, &src->fh_base, src->fh_size);
192}
193
194static __inline__ struct svc_fh *
195fh_init(struct svc_fh *fhp, int maxsize)
196{
197 memset(fhp, 0, sizeof(*fhp));
198 fhp->fh_maxsize = maxsize;
199 return fhp;
200}
201
202static inline bool fh_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
203{
204 if (fh1->fh_size != fh2->fh_size)
205 return false;
206 if (memcmp(fh1->fh_base.fh_pad, fh2->fh_base.fh_pad, fh1->fh_size) != 0)
207 return false;
208 return true;
209}
210
211static inline bool fh_fsid_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
212{
213 if (fh1->fh_fsid_type != fh2->fh_fsid_type)
214 return false;
215 if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0)
216 return false;
217 return true;
218}
219
220#ifdef CONFIG_CRC32
221/**
222 * knfsd_fh_hash - calculate the crc32 hash for the filehandle
223 * @fh - pointer to filehandle
224 *
225 * returns a crc32 hash for the filehandle that is compatible with
226 * the one displayed by "wireshark".
227 */
228static inline u32 knfsd_fh_hash(const struct knfsd_fh *fh)
229{
230 return ~crc32_le(0xFFFFFFFF, (unsigned char *)&fh->fh_base, fh->fh_size);
231}
232#else
233static inline u32 knfsd_fh_hash(const struct knfsd_fh *fh)
234{
235 return 0;
236}
237#endif
238
239#ifdef CONFIG_NFSD_V3
240/*
241 * The wcc data stored in current_fh should be cleared
242 * between compound ops.
243 */
244static inline void
245fh_clear_wcc(struct svc_fh *fhp)
246{
247 fhp->fh_post_saved = false;
248 fhp->fh_pre_saved = false;
249}
250
251/*
252 * We could use i_version alone as the change attribute. However,
253 * i_version can go backwards after a reboot. On its own that doesn't
254 * necessarily cause a problem, but if i_version goes backwards and then
255 * is incremented again it could reuse a value that was previously used
256 * before boot, and a client who queried the two values might
257 * incorrectly assume nothing changed.
258 *
259 * By using both ctime and the i_version counter we guarantee that as
260 * long as time doesn't go backwards we never reuse an old value.
261 */
262static inline u64 nfsd4_change_attribute(struct kstat *stat,
263 struct inode *inode)
264{
265 if (inode->i_sb->s_export_op->fetch_iversion)
266 return inode->i_sb->s_export_op->fetch_iversion(inode);
267 else if (IS_I_VERSION(inode)) {
268 u64 chattr;
269
270 chattr = stat->ctime.tv_sec;
271 chattr <<= 30;
272 chattr += stat->ctime.tv_nsec;
273 chattr += inode_query_iversion(inode);
274 return chattr;
275 } else
276 return time_to_chattr(&stat->ctime);
277}
278
279extern void fill_pre_wcc(struct svc_fh *fhp);
280extern void fill_post_wcc(struct svc_fh *fhp);
281#else
282#define fh_clear_wcc(ignored)
283#define fill_pre_wcc(ignored)
284#define fill_post_wcc(notused)
285#endif /* CONFIG_NFSD_V3 */
286
287
288/*
289 * Lock a file handle/inode
290 * NOTE: both fh_lock and fh_unlock are done "by hand" in
291 * vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
292 * so, any changes here should be reflected there.
293 */
294
295static inline void
296fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
297{
298 struct dentry *dentry = fhp->fh_dentry;
299 struct inode *inode;
300
301 BUG_ON(!dentry);
302
303 if (fhp->fh_locked) {
304 printk(KERN_WARNING "fh_lock: %pd2 already locked!\n",
305 dentry);
306 return;
307 }
308
309 inode = d_inode(dentry);
310 inode_lock_nested(inode, subclass);
311 fill_pre_wcc(fhp);
312 fhp->fh_locked = true;
313}
314
315static inline void
316fh_lock(struct svc_fh *fhp)
317{
318 fh_lock_nested(fhp, I_MUTEX_NORMAL);
319}
320
321/*
322 * Unlock a file handle/inode
323 */
324static inline void
325fh_unlock(struct svc_fh *fhp)
326{
327 if (fhp->fh_locked) {
328 fill_post_wcc(fhp);
329 inode_unlock(d_inode(fhp->fh_dentry));
330 fhp->fh_locked = false;
331 }
332}
333
334#endif /* _LINUX_NFSD_NFSFH_H */