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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
296/*
297 * We could use i_version alone as the change attribute. However,
298 * i_version can go backwards after a reboot. On its own that doesn't
299 * necessarily cause a problem, but if i_version goes backwards and then
300 * is incremented again it could reuse a value that was previously used
301 * before boot, and a client who queried the two values might
302 * incorrectly assume nothing changed.
303 *
304 * By using both ctime and the i_version counter we guarantee that as
305 * long as time doesn't go backwards we never reuse an old value.
306 */
307static inline u64 nfsd4_change_attribute(struct kstat *stat,
308 struct inode *inode)
309{
310 if (inode->i_sb->s_export_op->fetch_iversion)
311 return inode->i_sb->s_export_op->fetch_iversion(inode);
312 else if (IS_I_VERSION(inode)) {
313 u64 chattr;
314
315 chattr = stat->ctime.tv_sec;
316 chattr <<= 30;
317 chattr += stat->ctime.tv_nsec;
318 chattr += inode_query_iversion(inode);
319 return chattr;
320 } else
321 return time_to_chattr(&stat->ctime);
322}
323
324extern void fh_fill_pre_attrs(struct svc_fh *fhp);
325extern void fh_fill_post_attrs(struct svc_fh *fhp);
326extern void fh_fill_both_attrs(struct svc_fh *fhp);
327#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
16static inline __u32 ino_t_to_u32(ino_t ino)
17{
18 return (__u32) ino;
19}
20
21static inline ino_t u32_to_ino_t(__u32 uino)
22{
23 return (ino_t) uino;
24}
25
26/*
27 * This is the internal representation of an NFS handle used in knfsd.
28 * pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
29 */
30typedef struct svc_fh {
31 struct knfsd_fh fh_handle; /* FH data */
32 int fh_maxsize; /* max size for fh_handle */
33 struct dentry * fh_dentry; /* validated dentry */
34 struct svc_export * fh_export; /* export pointer */
35
36 bool fh_locked; /* inode locked by us */
37 bool fh_want_write; /* remount protection taken */
38
39#ifdef CONFIG_NFSD_V3
40 bool fh_post_saved; /* post-op attrs saved */
41 bool fh_pre_saved; /* pre-op attrs saved */
42
43 /* Pre-op attributes saved during fh_lock */
44 __u64 fh_pre_size; /* size before operation */
45 struct timespec fh_pre_mtime; /* mtime before oper */
46 struct timespec fh_pre_ctime; /* ctime before oper */
47 /*
48 * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode)
49 * to find out if it is valid.
50 */
51 u64 fh_pre_change;
52
53 /* Post-op attributes saved in fh_unlock */
54 struct kstat fh_post_attr; /* full attrs after operation */
55 u64 fh_post_change; /* nfsv4 change; see above */
56#endif /* CONFIG_NFSD_V3 */
57
58} svc_fh;
59
60enum nfsd_fsid {
61 FSID_DEV = 0,
62 FSID_NUM,
63 FSID_MAJOR_MINOR,
64 FSID_ENCODE_DEV,
65 FSID_UUID4_INUM,
66 FSID_UUID8,
67 FSID_UUID16,
68 FSID_UUID16_INUM,
69};
70
71enum fsid_source {
72 FSIDSOURCE_DEV,
73 FSIDSOURCE_FSID,
74 FSIDSOURCE_UUID,
75};
76extern enum fsid_source fsid_source(struct svc_fh *fhp);
77
78
79/*
80 * This might look a little large to "inline" but in all calls except
81 * one, 'vers' is constant so moste of the function disappears.
82 *
83 * In some cases the values are considered to be host endian and in
84 * others, net endian. fsidv is always considered to be u32 as the
85 * callers don't know which it will be. So we must use __force to keep
86 * sparse from complaining. Since these values are opaque to the
87 * client, that shouldn't be a problem.
88 */
89static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
90 u32 fsid, unsigned char *uuid)
91{
92 u32 *up;
93 switch(vers) {
94 case FSID_DEV:
95 fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) |
96 MINOR(dev));
97 fsidv[1] = ino_t_to_u32(ino);
98 break;
99 case FSID_NUM:
100 fsidv[0] = fsid;
101 break;
102 case FSID_MAJOR_MINOR:
103 fsidv[0] = (__force __u32)htonl(MAJOR(dev));
104 fsidv[1] = (__force __u32)htonl(MINOR(dev));
105 fsidv[2] = ino_t_to_u32(ino);
106 break;
107
108 case FSID_ENCODE_DEV:
109 fsidv[0] = new_encode_dev(dev);
110 fsidv[1] = ino_t_to_u32(ino);
111 break;
112
113 case FSID_UUID4_INUM:
114 /* 4 byte fsid and inode number */
115 up = (u32*)uuid;
116 fsidv[0] = ino_t_to_u32(ino);
117 fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
118 break;
119
120 case FSID_UUID8:
121 /* 8 byte fsid */
122 up = (u32*)uuid;
123 fsidv[0] = up[0] ^ up[2];
124 fsidv[1] = up[1] ^ up[3];
125 break;
126
127 case FSID_UUID16:
128 /* 16 byte fsid - NFSv3+ only */
129 memcpy(fsidv, uuid, 16);
130 break;
131
132 case FSID_UUID16_INUM:
133 /* 8 byte inode and 16 byte fsid */
134 *(u64*)fsidv = (u64)ino;
135 memcpy(fsidv+2, uuid, 16);
136 break;
137 default: BUG();
138 }
139}
140
141static inline int key_len(int type)
142{
143 switch(type) {
144 case FSID_DEV: return 8;
145 case FSID_NUM: return 4;
146 case FSID_MAJOR_MINOR: return 12;
147 case FSID_ENCODE_DEV: return 8;
148 case FSID_UUID4_INUM: return 8;
149 case FSID_UUID8: return 8;
150 case FSID_UUID16: return 16;
151 case FSID_UUID16_INUM: return 24;
152 default: return 0;
153 }
154}
155
156/*
157 * Shorthand for dprintk()'s
158 */
159extern char * SVCFH_fmt(struct svc_fh *fhp);
160
161/*
162 * Function prototypes
163 */
164__be32 fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int);
165__be32 fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
166__be32 fh_update(struct svc_fh *);
167void fh_put(struct svc_fh *);
168
169static __inline__ struct svc_fh *
170fh_copy(struct svc_fh *dst, struct svc_fh *src)
171{
172 WARN_ON(src->fh_dentry || src->fh_locked);
173
174 *dst = *src;
175 return dst;
176}
177
178static inline void
179fh_copy_shallow(struct knfsd_fh *dst, struct knfsd_fh *src)
180{
181 dst->fh_size = src->fh_size;
182 memcpy(&dst->fh_base, &src->fh_base, src->fh_size);
183}
184
185static __inline__ struct svc_fh *
186fh_init(struct svc_fh *fhp, int maxsize)
187{
188 memset(fhp, 0, sizeof(*fhp));
189 fhp->fh_maxsize = maxsize;
190 return fhp;
191}
192
193static inline bool fh_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
194{
195 if (fh1->fh_size != fh2->fh_size)
196 return false;
197 if (memcmp(fh1->fh_base.fh_pad, fh2->fh_base.fh_pad, fh1->fh_size) != 0)
198 return false;
199 return true;
200}
201
202static inline bool fh_fsid_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
203{
204 if (fh1->fh_fsid_type != fh2->fh_fsid_type)
205 return false;
206 if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0)
207 return false;
208 return true;
209}
210
211#ifdef CONFIG_CRC32
212/**
213 * knfsd_fh_hash - calculate the crc32 hash for the filehandle
214 * @fh - pointer to filehandle
215 *
216 * returns a crc32 hash for the filehandle that is compatible with
217 * the one displayed by "wireshark".
218 */
219
220static inline u32
221knfsd_fh_hash(struct knfsd_fh *fh)
222{
223 return ~crc32_le(0xFFFFFFFF, (unsigned char *)&fh->fh_base, fh->fh_size);
224}
225#else
226static inline u32
227knfsd_fh_hash(struct knfsd_fh *fh)
228{
229 return 0;
230}
231#endif
232
233#ifdef CONFIG_NFSD_V3
234/*
235 * The wcc data stored in current_fh should be cleared
236 * between compound ops.
237 */
238static inline void
239fh_clear_wcc(struct svc_fh *fhp)
240{
241 fhp->fh_post_saved = false;
242 fhp->fh_pre_saved = false;
243}
244
245/*
246 * We could use i_version alone as the change attribute. However,
247 * i_version can go backwards after a reboot. On its own that doesn't
248 * necessarily cause a problem, but if i_version goes backwards and then
249 * is incremented again it could reuse a value that was previously used
250 * before boot, and a client who queried the two values might
251 * incorrectly assume nothing changed.
252 *
253 * By using both ctime and the i_version counter we guarantee that as
254 * long as time doesn't go backwards we never reuse an old value.
255 */
256static inline u64 nfsd4_change_attribute(struct kstat *stat,
257 struct inode *inode)
258{
259 u64 chattr;
260
261 chattr = stat->ctime.tv_sec;
262 chattr <<= 30;
263 chattr += stat->ctime.tv_nsec;
264 chattr += inode_query_iversion(inode);
265 return chattr;
266}
267
268extern void fill_pre_wcc(struct svc_fh *fhp);
269extern void fill_post_wcc(struct svc_fh *fhp);
270#else
271#define fh_clear_wcc(ignored)
272#define fill_pre_wcc(ignored)
273#define fill_post_wcc(notused)
274#endif /* CONFIG_NFSD_V3 */
275
276
277/*
278 * Lock a file handle/inode
279 * NOTE: both fh_lock and fh_unlock are done "by hand" in
280 * vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
281 * so, any changes here should be reflected there.
282 */
283
284static inline void
285fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
286{
287 struct dentry *dentry = fhp->fh_dentry;
288 struct inode *inode;
289
290 BUG_ON(!dentry);
291
292 if (fhp->fh_locked) {
293 printk(KERN_WARNING "fh_lock: %pd2 already locked!\n",
294 dentry);
295 return;
296 }
297
298 inode = d_inode(dentry);
299 inode_lock_nested(inode, subclass);
300 fill_pre_wcc(fhp);
301 fhp->fh_locked = true;
302}
303
304static inline void
305fh_lock(struct svc_fh *fhp)
306{
307 fh_lock_nested(fhp, I_MUTEX_NORMAL);
308}
309
310/*
311 * Unlock a file handle/inode
312 */
313static inline void
314fh_unlock(struct svc_fh *fhp)
315{
316 if (fhp->fh_locked) {
317 fill_post_wcc(fhp);
318 inode_unlock(d_inode(fhp->fh_dentry));
319 fhp->fh_locked = false;
320 }
321}
322
323#endif /* _LINUX_NFSD_NFSFH_H */