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
ino_t_to_u32(ino_t ino)17 static inline __u32 ino_t_to_u32(ino_t ino)
18 {
19 return (__u32) ino;
20 }
21
u32_to_ino_t(__u32 uino)22 static 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 */
31 typedef 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
69 enum 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
80 enum fsid_source {
81 FSIDSOURCE_DEV,
82 FSIDSOURCE_FSID,
83 FSIDSOURCE_UUID,
84 };
85 extern 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 */
mk_fsid(int vers,u32 * fsidv,dev_t dev,ino_t ino,u32 fsid,unsigned char * uuid)98 static 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
key_len(int type)150 static 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 */
168 extern 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 *);
176 void fh_put(struct svc_fh *);
177
178 static __inline__ struct svc_fh *
fh_copy(struct svc_fh * dst,struct svc_fh * src)179 fh_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
187 static inline void
fh_copy_shallow(struct knfsd_fh * dst,struct knfsd_fh * src)188 fh_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
194 static __inline__ struct svc_fh *
fh_init(struct svc_fh * fhp,int maxsize)195 fh_init(struct svc_fh *fhp, int maxsize)
196 {
197 memset(fhp, 0, sizeof(*fhp));
198 fhp->fh_maxsize = maxsize;
199 return fhp;
200 }
201
fh_match(struct knfsd_fh * fh1,struct knfsd_fh * fh2)202 static 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
fh_fsid_match(struct knfsd_fh * fh1,struct knfsd_fh * fh2)211 static 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 */
knfsd_fh_hash(const struct knfsd_fh * fh)228 static 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
knfsd_fh_hash(const struct knfsd_fh * fh)233 static 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 */
244 static inline void
fh_clear_wcc(struct svc_fh * fhp)245 fh_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 */
nfsd4_change_attribute(struct kstat * stat,struct inode * inode)262 static 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
279 extern void fill_pre_wcc(struct svc_fh *fhp);
280 extern 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
295 static inline void
fh_lock_nested(struct svc_fh * fhp,unsigned int subclass)296 fh_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
315 static inline void
fh_lock(struct svc_fh * fhp)316 fh_lock(struct svc_fh *fhp)
317 {
318 fh_lock_nested(fhp, I_MUTEX_NORMAL);
319 }
320
321 /*
322 * Unlock a file handle/inode
323 */
324 static inline void
fh_unlock(struct svc_fh * fhp)325 fh_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 */
335